PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “squamous”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

Ber-EP4 immunoreactivity depends on the germ layer origin and maturity of the squamous epithelium.

AIM: To map the expression of Ber-EP4 in well-differentiated squamous epithelia, metaplastic squamous epithelia and dysplastic squamous epithelia of different origins. METHODS AND RESULTS: Squamous epithelium of different origin was stained using a standard immunohistochemistry method applied to paraffin sections. We found that normal squamous epithelium of the oral cavity, oesophagus, uterine cervix, vagina, anal canal, and branchial cysts are Ber-Ep4-negative, as are the mature squamous metaplasia of bronchial mucosa, urinary bladder mucosa and uterine cervical mucosa. In contrast, immature squamous metaplasia of bronchial mucosa, or uterine cervical mucosa, and squamous dysplasia of oral mucosa of endodermal origin, or uterine cervical mucosa in most cases expressed Ber-EP4. CONCLUSION: Squamous epithelia of ectodermal origin never express Ber-EP4, whether normal, hyperplastic, dysplastic or neoplastic. In contrast, squamous epithelium of endodermal origin sometimes contains the target glycoproteins of Ber-EP4 when immature, metaplastic, dysplastic or neoplastic. The results indicate that the differences in expression of Ber-EP4 in squamous epithelium depend primarily on germ layer origin, and on the maturity of the epithelium.

Antigens, Surface↗

Monitoring the course of cervical carcinoma with the squamous cell carcinoma serum radioimmunoassay.

Serum samples were collected from 611 gynecologic patients for measurement of squamous cell carcinoma antigen levels using the Abbott Laboratories squamous cell carcinoma antigen radioimmunoassay kit. Sixteen of 83 patients (19.3%) with cervical dysplasia and 72 of 135 (53.3%) with primary or recurrent cervical carcinoma had levels above 2.4 ng/mL. In contrast, only seven of 373 women (1.9%) without genital tract squamous cell intraepithelial neoplasia or carcinoma had squamous cell carcinoma antigen levels above 2.4 ng/mL. Fifty-six patients with cervical cancer were followed for correlation of squamous cell carcinoma antigen levels to disease course, and 20 had persistent or recurrent disease after therapy; rising squamous cell carcinoma antigen levels predicted disease in 15 of these 20 patients with recurrence (13 of 15 with elevated pre-treatment levels and two of five with normal pre-treatment levels). Rising squamous cell carcinoma antigen levels preceded the clinical detection of disease in ten patients by a mean of 4.6 months (range 2-7.5 months); in the remaining five, squamous cell carcinoma antigen levels were elevated only when disease recurrence was documented. Although measurement of squamous cell carcinoma antigen levels is not a sensitive screening method for cervical cancer (sensitivity 53.3%), the test has good specificity (94.3%); the majority of patients with false-positive elevations had other genital tract squamous cell neoplasias. The squamous cell carcinoma antigen assay may be a useful aid for monitoring the disease course of cervical carcinoma.

Antigens, Neoplasm↗

False-positive squamous cell carcinoma in cervical smears: cytologic-histologic correlation in 19 cases.

Cytologic features of squamous intraepithelial lesions (SIL) can mimic those of invasive squamous-cell carcinoma. We compare and correlate the cytological findings of 19 false-positive squamous-cell carcinomas with follow-up cone biopsies or hysterectomy specimens to define which type of dysplasia is more prone to diagnostic errors on cervical Papanicolaou (Pap) smears. Out of 128 patients diagnosed with invasive squamous-cell carcinoma from 1994-2000, 19 (14.8%) with follow-up cone biopsies or hysterectomy specimens were false-positive cases, showing only cervical intraepithelial neoplasia (CIN). We reviewed tissue sections from these 19 cases of CIN for cytologic features of squamous-cell carcinoma, such as markedly pleomorphic and/or dysplastic squamous cells, necrosis, and nucleoli. Twelve of 19 patients (63%) were menopausal. The mean age was 50.5 yr. On review of cervical smears, 18 cases qualified for the cytologic diagnosis of squamous-cell carcinoma, keratinizing type, and one case qualified for squamous-cell carcinoma, nonkeratinizing type. Pleomorphic and/or keratinizing dysplasia was found in 15 out of 19 patients (79%), necrosis within superficial endocervical glands in 9 out of 19 patients (47%), and conspicuous nucleoli in 12 out of 19 patients (63%). One or more of these changes were seen in all but 2 patients (89%). Endocervical gland involvement was present and extensive in 18 of the 19 cases (94%). The mean age was older than expected for SIL (50.5 vs. a reported 40), and matched the mean age found in patients with invasive squamous-cell carcinoma. Pleomorphic and/or keratinizing dysplasia involving endocervical glands may exhibit the cytologic features of squamous-cell carcinoma on cervical Pap smears.

Carcinoma, Squamous Cell↗

Paradoxically abundant expression of Bcl-2 and adrenomedullin in invasive cervical squamous carcinoma.

BACKGROUND: The purpose of this study was to identify the role of Bcl-2 protein and adrenomedullin (AM) expression in relation to apoptosis in the neoplastic changes of squamous epithelium of the uterine cervix. METHODS: Apoptosis in sections of normal cervical epithelium, cervical intraepithelial neoplasia (CIN), and invasive squamous cell carcinoma was determined by terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling (TUNEL) assay. Bcl-2 protein and AM expression were analyzed using the avidin-biotin immunoperoxidase method. RESULTS: On the basis of the TUNEL assay, the apoptosis positive rate of the nuclei in early invasive squamous carcinoma and in bulky invasive squamous carcinoma was significantly higher than that in normal cervical epithelium, but no such increase in the apoptosis-positive rate was noted in the nuclei in CIN. Immunohistochemical staining revealed that Bcl-2 protein and AM were immunolocalized in the cytoplasm of invasive squamous carcinoma cells, but not in either CIN lesions or normal cervical epithelium. Bcl-2 protein expression was more prominent in bulky invasive squamous carcinoma cells than in early invasive squamous carcinoma cells. AM expression was also more abundant in bulky invasive squamous carcinoma compared with that in early invasive squamous carcinoma. CONCLUSION: The present results suggest that the expression of Bcl-2 protein and AM in invasive squamous carcinoma may play crucial roles in selecting carcinoma cells resistant to apoptosis and in promoting malignant progression.

Adrenomedullin↗

Infrared coagulator: a useful tool for treating anal squamous intraepithelial lesions.

PURPOSE: The incidence of invasive anal squamous carcinoma in men who have sex with men is rising, particularly in those with human immunodeficiency virus. As in the cervix the high-grade squamous intraepithelial lesion is thought to be an invasive squamous cell carcinoma precursor. Cervical high-grade squamous intraepithelial lesions are treated by removing the squamocolumnar transition zone. This is not possible in the anus, where treatment is often surgical and is accompanied by significant pain and morbidity. Better office-based techniques to treat anal high-grade squamous intraepithelial lesions are needed. We employed the infrared coagulator in an office setting to ablate high-grade squamous intraepithelial lesions. METHODS: A retrospective review of medical records was performed on 68 human immunodeficiency virus-positive men who have sex with men who underwent infrared coagulator ablation of biopsy-proven high-grade dysplasia from the time we began using the procedure in 1999. All patients have had at least six months of follow-up. Procedures were performed with local anesthesia on patients with discrete high-grade squamous intraepithelial lesions. Follow-up consisted of anal cytology with high-resolution anoscopy and biopsy of suspicious areas every three to six months. New or recurrent high-grade dysplasia was retreated. Patients with circumferential or bulky disease were treated in the operating room and were excluded from the study. RESULTS: Altogether, 68 patients met the enrollment criteria. The median patient age was 41 years (range 29-62 years). A total of 165 lesions were treated (mean 1.6 lesions, range 1-5) and only 46 (28 percent) persisted. However, 44 patients (65 percent) developed a new or persistent high-grade squamous intraepithelial lesion within a median time of 217 days (range 27-566 days) after infrared coagulation. The remaining 24 patients (35 percent) were free of high-grade dysplasia for a median of 413 days (range 162-1313 days) after infrared coagulation. When patients were treated a second or third time, the incidence of new or persistent high-grade dysplasia dropped to 58 percent and 40 percent, respectively. The probability of curing a retreated lesion was 72 percent. Using generalized estimating equations, the incidence of high-grade dysplasia decreased with repeated infrared coagulator treatments. No patient developed squamous-cell carcinoma, had a serious adverse event, or developed anal stenosis. CONCLUSIONS: The infrared coagulator is a safe, office-based modality for treating anal high-grade squamous intraepithelial lesion in human immunodeficiency virus-positive men who have sex with men. Successive treatments led to decreased recurrence rates.

Adult↗

Surgical treatment of high-grade anal squamous intraepithelial lesions: a prospective study.

PURPOSE: The prevalence of anal squamous intraepithelial lesions is high among human immunodeficiency virus-positive homosexual males and, to a lesser extent, among human immunodeficiency virus-negative homosexual males. Furthermore, the incidence of high-grade squamous intraepithelial lesions, the putative precursor lesion to invasive cancer, is also high. We report the first prospective study of high-resolution anoscopy-directed surgical treatment of high-grade squamous intraepithelial lesions. METHODS: A prospective study of patients undergoing surgical treatment of high-grade squamous intraepithelial lesions (excision/cauterization of lesions visualized with high-resolution anoscopy) was performed. Follow-up anoscopy with biopsy and Papanicolaou smear was performed every three to six months. RESULTS: Patients diagnosed with high-grade squamous intraepithelial lesions during the course of their participation in a prospective cohort study of anal squamous intraepithelial lesions were identified. From this group, 37 patients who were treated surgically between 1995 and 1999 were studied. Of these, 29 had tested positive for human immunodeficiency virus and 8 were negative for the virus. Mean patient age was 45 +/- 8 years. Mean duration of follow-up was 32.3 +/- 20.6 months in the human immunodeficiency virus-negative group and 28.6 +/- 12.9 months in the human immunodeficiency virus-positive group. No human immunodeficiency virus-negative patient developed recurrent high-grade squamous intraepithelial lesions. Twenty-three of 29 human immunodeficiency virus-positive patients had persistent or recurrent high-grade squamous intraepithelial lesions (P = 0.003; mean time to recurrence, 12 months). Six patients underwent reoperation for high-grade squamous intraepithelial lesions (4 recurred by 6 months). No patients developed incontinence, stenosis, postoperative infection, or significant bleeding after surgical treatment. CONCLUSIONS: Surgical intervention directed by high-resolution anoscopy is safe and eliminates high-grade squamous intraepithelial lesions in human immunodeficiency virus-negative patients. The high persistence or recurrence rate in human immunodeficiency virus-positive patients suggests that multiple staged procedures and continued surveillance may be necessary.

Adult↗

Overexpression of phosphorylated nuclear factor-kappa B in tonsillar squamous cell carcinoma and high-grade dysplasia is associated with poor prognosis.

Intracellular signals along the epidermal growth factor receptor (EGFR)-Akt-nuclear factor-kappa B (NF-kappaB) pathway have been associated with carcinogenesis in various malignant neoplasms. This investigation was to evaluate the expression of EGFR, phosphorylated(p)-Akt and p-NF-kappaB and correlate them with clinical outcomes in patients with squamous cell carcinoma of the tonsil. A total of 45 patients with squamous cell carcinoma of the tonsil were studied by immunohistochemistry to evaluate the expression levels of EGFR, p-Akt and p-NF-kappaB. Results for squamous cell carcinoma of the tonsil were compared with those for associated high-grade dysplasia and adjacent normal appearing epithelium, when present. In addition, tonsillar epithelium from non-neoplastic specimens of age-matched patients also was stained for the same markers. High-grade dysplasia and squamous cell carcinoma of the tonsil demonstrated a similar pattern of expression, which differed from the pattern seen in the adjacent normal epithelium and tonsillar epithelium from normal controls (an overexpression for each of these three protein analytes in high-grade dysplasia and squamous cell carcinoma of the tonsil as demonstrated by immunohistochemistry). When markers from squamous cell carcinoma of the tonsil were correlated with survival status, only increasing levels of p-NF-kappaB immunoreactivity (a relative overexpression) were statistically significant predictors of poor survival. No markers in squamous cell carcinoma of the tonsil were significantly related to rate of recurrence. When analyzing marker scores from tissue with high-grade dysplasia, relative overexpressions of both p-Akt and p-NF-kappaB were significantly related to poor survival. Additionally, increasing levels of p-NF-kappaB immunopositivity from tissue with high-grade dysplasia were also significantly related to rate of recurrence. In summary, p-NF-kappaB, overexpressed in high-grade dysplasia and squamous cell carcinoma of the tonsil, is associated with worse prognosis in terms of high recurrence and poor survival, respectively. This significant finding in patients with squamous cell carcinoma of the tonsil, in combination with previous animal and in vitro studies, suggests that p-NF-kappaB represents a potential therapeutic target in head and neck squamous cell carcinoma.

Aged↗

Ki67 expression in lichen sclerosus of vulva in patients with and without associated squamous cell carcinoma.

AIMS: To investigate the malignant potential of lichen sclerosus, a study using the cell proliferation marker Ki67 comparing lichen sclerosus with and without associated squamous cell carcinoma was performed. METHODS AND RESULTS: Formalin-fixed, paraffin-embedded slides of 13 cases of lichen sclerosus with associated carcinoma, and 31 cases without associated carcinoma, including 16 random cases, seven with epidermal thickening and eight with epidermal thinning, were examined by the immunoperoxidase technique for Ki67, a cell proliferation marker. Ki67 reactivity was mostly seen in the basal and parabasal cells in both groups of lichen sclerosus and this pattern was similar to normal skin, squamous cell hyperplasia and analogous to that of one form of squamous cell carcinoma. There was a mean of 50 Ki67 positive cells per 100 basal cells in lichen sclerosus with associated squamous cell carcinoma; however, in squamous cell hyperplasia adjacent to carcinoma this rose to 90 Ki67 positive cells per 100 basal cells. In lichen sclerosus without associated carcinoma, the random cases had a count of 53 per 100 basal cells, those with epidermal thickening 53 and those with thinning 42. Non-genital normal skin had a count of 71 per 100 basal cells. CONCLUSION: The lack of qualitative differences of Ki67 expression in normal skin, in lichen sclerosus with and without carcinoma, in squamous cell hyperplasia and in one form of squamous cell carcinoma indicates that these conditions share a common localized pattern of cell proliferation and does not support or deny the malignant potential of lichen sclerosus. The higher Ki67 count in squamous cell hyperplasia adjacent to carcinoma could indicate premalignancy or a reaction to the carcinoma. In patients without carcinoma, the higher Ki67 count in thickened lichen sclerosus compared to thinned suggests that some or all of the cases of thickened lichen sclerosus were lichen sclerosus with squamous cell hyperplasia or that lichen simplex chronicus superimposed on lichen sclerosus has a higher Ki67 expression or that the distinction between squamous cell hyperplasia and lichen simplex chronicus is only one of terminology.

Basal Cell Carcinoma↗

PTCH mutations in squamous cell carcinoma of the skin.

Ultraviolet light exposure is the major risk factor for the development of squamous cell carcinoma in Caucasians. Mutations in the tumor suppressor gene p53 have been identified in both squamous cell carcinomas and basal cell carcinomas. The human homolog of the Drosophila patched gene, has been shown to be mutated in sporadic basal cell carcinomas; however, mutations in the patched gene have not been found in squamous cell carcinoma. In this study, we screened a total of 20 squamous cell carcinoma samples for mutations in the patched gene. Using polymerase chain reaction-single strand conformation polymorphism as an initial screening method, we identified one non-sense mutation, two mis-sense mutations and three silent mutations in five squamous cell carcinoma samples. In one squamous cell carcinoma sample, we identified a tandem GG-->AA transitional change at nucleotide 3152 in exon 18 of the patched gene that resulted in a premature stop codon at codon 1051. The three squamous cell carcinoma samples containing non-sense and mis-sense mutations were isolated from individuals with histories of multiple basal cell carcinoma. Sequence analysis of the p53 gene in these five squamous cell carcinoma samples identified one CC-->TT and three C-->T ultraviolet-specific nucleotide changes. Our study provides evidence that the patched gene is mutated in squamous cell carcinoma from individuals with a history of multiple basal cell carcinoma. The identification of ultraviolet-specific nucleotide changes in both tumor suppressor genes supports the notion that ultraviolet exposure plays an important part in the development of squamous cell carcinoma.

Aged↗

Squamous metaplasia of the prostate. An immunohistochemical study.

Immunoperoxidase strains for prostate-specific antigen (PSA), prostatic acid phosphatase (PAcP), epithelial membrane antigen (EMA), and cytokeratins (MAK 6 and CK-KES) were performed on 1 case of squamous cell carcinoma of the prostate and on 13 cases of squamous metaplasia of prostatic epithelium in an effort to demonstrate prostatic origin of the neoplastic and metaplastic cells and to differentiate them from primary or metastatic well-differentiated squamous cell carcinoma. The authors found no specific staining of the metaplastic or neoplastic cells for PSA and only focal single cell PAcP positivity in three cases of squamous metaplasia. All cases showed strong staining of surrounding normal glandular epithelium for both antigens. In all but one case, both the metaplastic and glandular epithelium had positive results for MAK 6 and CK-KES. EMA was expressed strongly in ten cases, was weak or variable in two, and had negative results in two cases of squamous metaplasia. In only four cases did the glandular epithelium have positive results for EMA. The remaining cases showed no staining. PSA and PAcP marking, therefore, may not be useful for separating atypical squamous metaplasia from well-differentiated squamous cell carcinoma or even primary prostatic from metastatic squamous cell carcinoma. These findings suggest that although prostatic glandular epithelial cells retain their ability to express some prostate-associated antigens, this ability is greatly reduced, lost, or not developed in cells that undergo metaplasia into squamous cells or that develop into squamous cell carcinoma.

Aged↗

Utility of peanut agglutinin (PNA) in the diagnosis of squamous cell carcinoma and keratoacanthoma.

Lectins are glycoproteins that bind to specific carbohydrate groups on cell surfaces. Peanut lectin (PNA) binds to carbohydrates on the membranes of normal keratinocytes. Recently, some authors have proposed that PNA may be a useful marker to help differentiate keratoacanthomas from well-differentiated squamous cell carcinomas of the skin. We studied a total of 34 skin biopsy specimens, including 11 keratoacanthomas, 15 well-differentiated squamous cell carcinomas, and 8 poorly differentiated squamous cell carcinomas, using peanut lectin with the avidin-biotin complex (ABC) peroxidase technique. All keratoacanthomas demonstrated uniform positive membrane staining of keratinocytes, which was identical to PNA staining in normal skin. Keratinocytes in 80% of the well-differentiated squamous cell carcinomas and keratinocytes in all the poorly differentiated squamous cell carcinomas did not stain. With prior digestion by neuraminidase, however, positive membrane staining for PNA was demonstrated in the squamous cells of all well-differentiated squamous cell carcinomas and all but one case of the poorly differentiated squamous cell carcinomas. Our results support the efficacy of PNA in most cases as a marker to aid in the often difficult histologic differentiation of keratoacanthoma from well-differentiated squamous cell carcinoma. Our findings also support those of previous authors who suggested that the negative PNA stain of malignant squamous cells is not the result of a lack of PNA receptors, but is due instead to a masking of receptor sites by terminal sialic acid residues.

Arachis↗

Prostate carcinoma with squamous differentiation: an analysis of 33 cases.

BACKGROUND: Only sporadic cases of prostate carcinomas with squamous differentiation have been reported. DESIGN: The files of two institutions were reviewed for prostate cancers with squamous differentiation. RESULTS: A total of 33 cases were studied. The average age at diagnosis was 68 years (range 49-86 years). The most common presenting symptoms included bladder outlet obstruction and dysuria. Thirteen men had a positive digital rectal examination. Diagnosis was made by needle biopsy (n = 23); transurethral resection of the prostate (n = 5); needle and transurethral resection of the prostate (n = 1); transurethral resection of the bladder (n = 1); or biopsy of metastases (n = 3). In 21 of 33 cases, there was a prior diagnosis of adenocarcinoma of the prostate; 8 patients were treated with hormones, 4 were treated with radiation, and 1 received both radiation and hormone therapy. Of the 12 men without a prior diagnosis of adenocarcinoma, 2 patients had received hormonal therapy for benign prostatic hyperplasia. Eight of 33 cases were pure squamous carcinomas. The remaining cases were adenosquamous carcinoma (n = 16), adenosquamous and urothelial carcinoma (n = 3), and adenosquamous carcinoma and sarcoma (n = 6). The squamous carcinoma component of these mixed cases averaged 40% of the tumor volume (range 5%-95%) and had a range of cytologic atypia (mild [n = 6], moderate [n = 17], severe [n = 10]). In the 25 cases with adenocarcinoma, the glandular component tended to be high-grade (Gleason grade >6 in 19 cases). Immunohistochemistry for prostate specific acid phosphatase and prostate specific antigen was positive in a large percentage of the adenocarcinomas (85% and 75%, respectively) and only very focally positive in 12% of the squamous carcinomas. 34 beta E12 was diffusely positive in >95% of the squamous carcinomas and only focally positive in <10% of the adenocarcinomas. Cytokeratins 7 and 20 did not differentiate the squamous and adenocarcinoma components. Follow-up was available on 25 of 33 cases, with the average survival being 24 months (range 0-63 months). CONCLUSION: Squamous differentiation in prostate cancer is uncommon, often but not necessarily arising in the setting of prior hormone or radiation therapy, and is associated with a poor prognosis. In addition to pure squamous cell carcinoma and adenosquamous cancer, other patterns may be seen. Whereas the adenocarcinoma component is typically high grade, the squamous component has a wide range of differentiation.

Acid Phosphatase↗

VCAM (CD-106) and ICAM (CD-54) adhesion molecules distinguish keratoacanthomas from cutaneous squamous cell carcinomas.

Keratoacanthomas are rapidly growing benign epithelial derived neoplasms that may evolve into squamous cell carcinomas, or represent a variant of squamous cell carcinoma. ICAM (CD-54) is a ligand for the cell adhesion receptor LFA-1, shown to be important in immune stimulation that is upgraded in inflammatory cutaneous disorders. VCAM (CD-106) is an adhesion molecule normally found in stimulated endothelium, that plays a critical role in the migration of leukocytes. We examined the immunohistochemical expression of ICAM (CD-54) and VCAM (CD-106) in a series of 50 evolving, fully developed, resolving keratoacanthoma and well-differentiated and poorly differentiated squamous cell carcinoma to evaluate the possible temporal and pathogenic relation of these immune recognition markers and epithelial derived tumors. ICAM (CD-54) showed an increase in expression in the fully developed keratoacanthoma and was absent in the evolving and resolved keratoacanthoma. In the squamous cell carcinomas, expression was focally observed in the well-differentiated squamous cell carcinomas with a dramatic increase seen in the poorly differentiated squamous cell carcinomas. Similarly, VCAM (CD-106) was expressed in the fully developed keratoacanthoma and was absent in the evolving and resolved keratoacanthoma. Moderate expression for VCAM (CD-106) was seen in the well-differentiated squamous cell carcinoma, and intense expression was seen in the fully developed keratoacanthoma and poorly differentiated squamous cell carcinoma. As a group, keratoacanthoma and squamous cell carcinoma are immunophenotypically distinct. There is a temporal related increase in expression of VCAM (CD-106) in conjunction with the evolution of keratoacanthoma. Increased expression of both markers is seen with squamous cell carcinoma dedifferentiation. Application of these markers might be an important adjunct in predicting the biologic behavior and pathogenesis of these lesions.

Aged↗

The limited difference between keratin patterns of squamous cell carcinomas and adenocarcinomas is explicable by both cell lineage and state of differentiation of tumour cells.

AIM: To study the differentiation of epithelial tissues within their histological context, and to identify hypothetically, on the basis of keratin pattern, the putative tissue origin of a (metastatic) carcinoma. METHODS: Using well characterised monoclonal antibodies against individual keratins 7, 8, 18, and 19, which are predominantly found in columnar epithelia, and keratins 4, 10, 13, and 14, predominantly expressed in (non)-keratinising squamous epithelia, the keratin patterns for a series of 45 squamous cell carcinomas and 44 adenocarcinomas originating from various epithelial tissues were characterised. RESULTS: The predominant keratins in all adenocarcinomas proved to be 8, 18, and 19. In addition, these keratins were also abundantly present in squamous cell carcinomas of the lung, cervix, and rectum and, to a lesser extent, of the larynx, oesophagus, and tongue, but not in those of the vulva and skin. Keratins 4, 10, 13, and 14 were present in almost all squamous cell carcinomas, but also focally in some of the adenocarcinomas studied. CONCLUSIONS: There is a limited differential expression of distinctive keratin filaments between squamous cell carcinomas and adenocarcinomas. Apparently, squamous cell carcinomas that originate from columnar epithelium by squamous metaplasia gain the keratins of squamous cells but retain the keratins of columnar epithelial cells. However, the simultaneous expression of two of three squamous keratins (4, 10, and 13) identifies a squamous cell carcinoma, and thus might be useful in solving differential diagnostic problems.

Adenocarcinoma↗

Squamous metaplasia induced by transfection of human papillomavirus DNA into cultured adenocarcinoma cells.

BACKGROUND/AIM: It has been reported previously in cases of adenosquamous carcinoma of the lung in Okinawa, a subtropical island 2000 km south of mainland Japan, that the squamous cell carcinoma components were positive for human papillomavirus (HPV) by non-isotopic in situ hybridisation (NISH). The adenocarcinoma cells adjacent to the squamous cell carcinoma components were enlarged and also positive for HPV. This is thought to indicate that after adenocarcinoma cells are infected with HPV, they undergo morphological changes, and that "squamous metaplasia" follows. In this present study, the effects of HPV transfection into adenocarcinoma cells were examined. The relation between the region expressing the HPV gene and squamous metaplasia was also studied. METHODS: Plasmid pBR322 containing HPV type 16 (HPV-16) was transfected into cultured colonic adenocarcinoma (DLD-1) and lung adenocarcinoma (PC-14) cells using the calcium phosphate method. Neomycin was used as a selection marker. The presence of HPV E1, E2, E4, E5, E6, E7, L1, and L2 mRNAs and also transglutaminase 1, involucrin, cyclin dependent kinases (CDKs), cyclins, caspases, apoptosis inducing factor, DNase gamma, Fas, and Fas ligand mRNAs in HPV transfected cells was investigated by means of reverse transcription polymerase chain reaction (RT-PCR). The G0-G1 cell population was analysed by flow cytometry. Morphological examination under light and electron microscopes was also carried out. RESULTS: The virus transfected cells showed squamous metaplasia when they were injected into severe combined immunodeficient mice, expressing the high molecular weight keratin (Moll's number 1 keratin) and involucrin molecules immunohistochemically, and involucrin and transglutaminase I mRNAs by RT-PCR. The squamous metaplasia was most conspicuous in the HPV transfected DLD-1 cell when compared with HPV transfected PC-14 cells. Squamous metaplasia was most clearly demonstrated in one HPV transfected DLD-1 cell clone, which expressed not only E2 but also E6-E7 fusion gene mRNA. Viral L1 mRNA expression was absent in HPV transfected cell clones, and was not related to squamous metaplasia. The growth rate of HPV transfected cells was reduced. Transfection of the virus into the cultured adenocarcinoma cells increased the G0-G1 cell population greatly, as assessed by flow cytometer analysis. Furthermore, in the virus transfected cells, apoptosis was also observed by means of the terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labelling method. CONCLUSION: HPV transfection into adenocarcinoma cells induced clear squamous metaplasia. One of the HPV transfected cell clones that expressed E2 and E6-E7 fusion gene mRNA showed the squamous metaplasia particularly clearly, and apoptosis was also demonstrated.

Adenocarcinoma↗

Squamous metaplasia of bronchiolar cell-derived adenocarcinoma induced by N-nitrosomethyl-n-heptylamine in Syrian hamsters.

Morphology and development of experimental bronchiolar lung tumors were studied in Syrian hamsters, using light and electron microscopic techniques. At the age of 9 weeks, 46 hamsters were each given one weekly gavage of 6.8 mg N-nitrosomethyl-n-heptylamine for 35 weeks, and hamsters were examined at intervals from 2 to 46 weeks. The present report describes the progression of adenocarcinomas of bronchiolar cell origin to adenosquamous and squamous cell carcinomas. Squamous metaplasia was commonly noted at the tumor periphery, i.e., zone of growth. In 20 hamsters, 22 adenosquamous and two squamous cell carcinomas (one a large cell carcinoma) were diagnosed by light microscopy. Overt keratinization was infrequent. Squamous cell metaplasia was not a feature of papillary neoplasms but was seen mainly with acinar structures. Ultrastructurally, squamous differentiation (metaplasia) appeared to develop along two different pathways. First, secretory cells were observed with large numbers of intermediate filaments and tonofilaments, with concurrent loss of organelles such as secretory granules and microvilli. Second, squamous metaplasia also appeared to develop from a progeny of tumor cells that failed to mature into secretory cells. Such cells were often present within the basal layer of secretory acini and resembled basal cells of the tracheobronchial tree. These observations were supported by increased expression of cytokeratins, as revealed by immunohistochemical procedures. Immunoelectron microscopic examination localized hamster Clara cell antigen in secretory granules of neoplastic Clara cells, in the cytoplasm between granules, and at the microvillous border. With the onset of squamous differentiation, Clara cell antigen was progressively lost from secretory cells and was only rarely seen in cells with tonofilaments. No labeling was present in squamous cells arising at the base of tumor acini. These results suggest that pulmonary squamous cell carcinomas may develop by direct squamous differentiation of secretory cells or may proceed from undifferentiated tumor cells.

Animals↗

Further evidence for a novel receptor for amino-terminal parathyroid hormone-related protein on keratinocytes and squamous carcinoma cell lines.

PTH and PTH-related peptides (PTHrPs) interact with a common PTH/PTHrP receptor (type I), which is expressed in many tissues, including bone and kidney. Amino-terminal PTH and PTHrPs also recognize receptors in several nonclassical PTH target tissues, and in some of these, the signaling mechanisms differ qualitatively from those of the classical type I receptor. In normal keratinocytes and squamous carcinoma cell lines, PTH and PTHrP stimulate a rise in intracellular calcium, but not cAMP, suggesting the existence of an alternate, type II PTH/PTHrP receptor. SqCC/Y1 squamous carcinoma cells stably expressing the type I receptor displayed sensitive intracellular cAMP responses to PTHrP and PTH, indicating that these cells express functional GS proteins and that the type I receptor is capable of signaling through adenylyl cyclase in this cell line. Therefore, the endogenous type II receptor in SqCC/Y1 cells differs from the cloned type I receptor. We next examined whether messenger RNA (mRNA) from keratinocytes and squamous cell lines could hybridize to a human type I PTH/PTHrP receptor complementary DNA [1.9 kilobases (kb)]. No type I receptor mRNA (2.3 kb) was detected in polyadenylated RNA from any of the squamous cell lines. However, squamous cell lines did express several mRNA transcripts that hybridized with the type I receptor probe, yet were smaller (1 and 1.5 kb) or larger (3.5-5 kb) than the cloned receptor mRNA. The predominant mRNA in two squamous carcinoma cell lines and normal keratinocytes was a 1-kb transcript. Northern analysis with five different region-specific probes that span the entire coding region of the human type I receptor was used to map homologous regions within each of the transcripts. Several of the transcripts identified in squamous lines are also present in polyadenylated RNA from SaOS-2 human bone cells, but a unique 1-kb transcript hybridizing to probe 2 (nucleotides 490-870) was observed only in squamous cells. The smaller 1- and 1.5-kb transcripts did not hybridize to probes corresponding to the extreme 5'- and 3'-coding regions of the type I receptor complementary DNA. Ribonuclease protection analysis employing riboprobes that correspond to the five region-specific DNA probes revealed strong RNA signals of the expected size in SaOS-2 cells, but no hybridization with squamous cell RNA. Several smaller, but minor, bands that were unique to squamous cells were observed with riboprobe 2 only, suggesting partial homology of this region with the type I receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Base Sequence↗

In situ hybridization study on human papillomavirus DNA expression in benign and malignant squamous lesions of the esophagus.

Histologic changes suggesting HPV infection are occasionally found adjacent to squamous cell carcinoma or in squamous papilloma of the esophagus, but the relationship between HPV infection and benign and malignant squamous lesions of the esophagus is not yet dear. The aim of this study was to examine the role of HPV in squamous lesions of the esophagus. Microscopic examination with emphasis on HPV infection was done on 15 cases of squamous cell carcinoma and 26 cases of squamous papilloma. In situ hybridization technique for wide-spectrum HPV probe was performed on 35 endoscopically biopsied esophageal tissues. Among the histologic parameters suggesting HPV infection, acanthosis was the most frequent finding: 100.0% in benign and malignant esophageal lesions, and koilocytosis and intraepithelial capillary loops were the second (92.7%).: Dyskeratosis, basal cell hyperplasia and bi- or multinucleation were 52.3%, 44.0% and 34.1% in frequency, respectively. On in situ hybridization study, the HPV DNA expression rates of 10 squamous cell carcinomas with evidence of HPV infection and 15 carcinomas without evidence of HPV infection were 60.0% and 33.3%, respectively. In contrast to the carcinoma cases, only one (10.0%) of 10 squamous papillomas revealed positive signal. In conclusion, HPV infection is strongly associated with squamous cell carcinoma, but the causal relation of HPV to squamous papilloma is inconspicous.

DNA, Viral↗