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Biomedical subjects

Ryuichi Nakashima

Publications and source records attributed to Ryuichi Nakashima.

9 recordsLinked to original sources

Prognostic significance of p53 mutation in suboptimally resected advanced ovarian carcinoma treated with the combination chemotherapy of paclitaxel and carboplatin.

The prognostic significance of p53 mutation, microsattelite instability and DNA mismatch protein hMLH1 expression in suboptimally resected advanced ovarian carcinoma treated with the combination chemotherapy of paclitaxel and carboplatin was evaluated. The overall combination chemotherapy response rate and the complete remission rate were significantly higher among patients with mutant p53 tumors than those with wild-type p53 tumors (35/42 (83%) vs. 32/58 (55%); P=0.003 and 18/42 (43%) vs. 16/58 (28%); P=0.03, respectively). This tendency apparently existed in non-serous carcinoma, but not in serous carcinoma. Univariate analysis showed that the risk of death due to disease and risk of progression was significantly lower among patients with p53 mutation (P=0.0357 and 0.0281, respectively). However, the presence of microsattelite instability or loss of hMLH1 expression was not associated with either the clinical response or prognosis. Determining p53 mutational status can be useful in predicting therapeutic response to drugs in ovarian carcinoma, especially in non-serous tumors.

Adenocarcinoma, Clear Cell↗

Overexpression of LAMP3/TSC403/DC-LAMP promotes metastasis in uterine cervical cancer.

LAMP3 (DC-LAMP, TSC403, CD208) was originally isolated as a gene specifically expressed in lung tissues. LAMP3 is located on a chromosome 3q segment that is frequently amplified in some human cancers, including uterine cervical cancer. Because two other members of the LAMP family of lysosomal membrane glycoproteins, LAMP1 and LAMP2, were previously implicated in potentially modulating the interaction of vascular endothelial and cancer cells, we hypothesized that LAMP3 might also play an important part in metastasis. To clarify the metastatic potential of LAMP3 in cervical cancers, we transfected a LAMP3 expression vector into a human uterine cervical cancer cell line, TCS. In an in vitro invasion assay, the migration of LAMP3-overexpressing TCS cells was significantly higher than in control TCS cells. In an in vivo metastasis assay, distant metastasis was detected in 9 of 11 LAMP3-overexpressing TCS cell-injected mice and in only 1 of 11 control mice. Histologic study showed that LAMP3-overexpressing cells readily invaded into the lymph-vascular space. In clinical samples, quantitative real-time reverse transcription-PCR (RT-PCR) analyses showed that LAMP3 mRNA was significantly up-regulated in 47 of 47 (100%) cervical cancers and in 2 of 15 (13%) cervical intraepithelial neoplasias, compared with a low level of LAMP3 mRNA expressed in normal uterine cervixes. Interestingly, high LAMP3 expression was significantly correlated with the overall survival of patients with stage I/II cervical cancers. These findings indicate that LAMP3 overexpression is associated with an enhanced metastatic potential and may be a prognostic factor for cervical cancer.

Animals↗

Altered protein expression in endometrial carcinogenesis.

We have discovered several protein biomarkers that are altered during carcinogenesis of the human uterine endometrium. Proteins prepared from 19 endometrial carcinomas (Group A), and 20 normal endometria obtained from benign gynecological conditions (Group B), were investigated by Surface Enhanced Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SELDI-TOF-MS). Two proteins, EC1 and EC2, were consistently expressed differentially. EC1 had an increased level of expression in carcinomas (P<0.001), while EC2 was expressed at a lower level (P=0.004). The isoelectric points of EC1 and EC2 were approximately pH 5.0 and 7.0, respectively. These proteins are thus potential biomarkers for detection of endometrial carcinoma.

Adult↗

Correlation between p14(ARF)/p16(INK4A) expression and HPV infection in uterine cervical cancer.

The CDKN2A locus on human chromosome 9p21 encodes two tumor suppressors, p14(ARF) and p16(INK4A), which enhance the growth-suppressive functions of the retinoblastoma (Rb) and the p53 proteins, respectively. Conversely, the E6 and E7 oncoproteins of the high-risk human papillomaviruses (HPVs) causally associated with carcinogenesis of the uterine cervix contributes to tumor development by inactivating p53 and Rb. Nevertheless, a correlation between expression of p14(ARF)/p16(INK4A) and HPV infection in uterine cervix is less clear. To clarify this, we examined 25 cervical cancers and 11 normal uterine cervixes. HPV was detected in 21 of 25 cervical cancers (84%) and their subtype was determined by PCR-RFLP. Quantitative real-time RT-PCR assays showed overexpression of p14(ARF) mRNA in all 21 HPV-positive cases (100%). p16(INK4A) mRNA was overexpressed in 17 cases of the HPV-positive cases (81%). In four HPV-negative cancers, reduced expression of p14(ARF) mRNA was detected in two cases (50%) and reduced p16(INK4A) mRNA in three cases (75%). Our data indicate that the overexpression of p14(ARF) and p16(INK4A) strongly associates with HPV-positive cervical cancers and that reduced expression of p14(ARF) and p16(INK4A) correlates with HPV-negative cervical cancers. These findings may indicate that impaired p14(ARF) and p16(INK4A) mRNA expression contribute to tumor development in HPV-negative cervical cancers by failure to support p53 and Rb instead of their inactivation by HPV E6 and E7.

Carcinoma, Squamous Cell↗

Analysis of clonality and HPV infection in benign, hyperplastic, premalignant, and malignant lesions of the vulvar mucosa.

To elucidate the pathogenesis of vulvar carcinomas, we studied clonality and human papillomavirus (HPV) infection in vulvar epithelial diseases. Monoclonal composition was demonstrated in all 9 invasive tumors (squamous cell carcinoma [SCC], 6; basal cell carcinoma, 1; malignant melanoma, 2), 15 of 20 cases of vulvar intraepithelial neoplasia (VIN), 7 of 9 cases of Paget disease, 2 of 6 cases of lichen sclerosus (LS), and 2 of 3 cases of squamous cell hyperplasia (SCH); high-risk type HPV was revealed in 5 of 6 SCCs and 17 of 20 VINs. These observations might imply that a subset of cases of LS and SCH result from a neoplastic proliferation, similar to VINs but not related to infection with high-risk type HPV. In 1 case of SCC with concurrent VIN 3 in an adjacent lesion, both lesions showed the same pattern of X chromosome inactivation and the presence of HPV-16 in episomal and integrated forms, suggesting that monoclonal expansion triggered by high-risk type HPV integration is an early event for carcinogenesis of HPV-associated SCC.

Carcinoma in Situ↗

Mutations in the STK11 gene characterize minimal deviation adenocarcinoma of the uterine cervix.

Minimal deviation adenocarcinoma (MDA) is a well-differentiated variant of mucinous adenocarcinoma of the uterine cervix and is found relatively infrequently in the general population. However, MDA is strongly associated with Peutz-Jeghers syndrome (PJS), a rare hereditary autosomal disorder characterized by benign hamartomatous polyposis in the gastrointestinal tract and mucocutaneous pigmentation. A serine threonine kinase gene, STK11, has been identified as the tumor suppressor gene responsible for the PJS. In this study we investigated the possible direct role of STK11 in the development of MDA of the uterine cervix. Eleven rare cases of mucinous MDA, not known to be associated with PJS, were screened for the presence of mutations in the STK11 gene by single-strand conformation polymorphism analysis of PCR-amplified DNA fragments. Subsequently our findings were confirmed with cloning and sequencing. As a control, 24 cases of endocervical adenocarcinomas of other histologic subtypes, with no family history of PJS (19 mucinous adenocarcinomas, 4 endometrioid adenocarcinomas, and 1 clear cell adenocarcinoma), 15 cases of squamous cell carcinomas of the uterine cervix, 5 cases of endocervical glands with pyloric gland metaplasia, and 2 deeply situated nabothian cysts were investigated. Somatic mutations of the STK11 gene were confirmed in 6 (55%) of the 11 mucinous MDAs and 1 (5%) of the 19 mucinous adenocarcinomas, but not in the 5 nonmucinous adenocarcinomas, the 15 squamous cell carcinomas, nor the 5 endocervical glands with gastric metaplasia. MDAs with the STK11 mutation had a significantly poorer prognosis than MDAs without the STK11 mutation (p = 0.039). A germline mutation of STK11 was detected in one PJS patient with mucinous adenocarcinoma of the uterine cervix. These results suggest that mutations in the STK11 gene may play an important role in the etiology of MDA of the uterine cervix and may distinguish this rare tumor from other common types of adenocarcinoma of the uterine cervix.

AMP-Activated Protein Kinase Kinases↗

Monoclonal expansion with integration of high-risk type human papillomaviruses is an initial step for cervical carcinogenesis: association of clonal status and human papillomavirus infection with clinical outcome in cervical intraepithelial neoplasia.

To define the natural history of cervical intraepithelial neoplasia (CIN) as related to clonal status, we evaluated 20 cases of CIN1 and 18 cases of CIN2 that had been clinically followed for 7 to 48 months at Osaka University Hospital. These included 10 cases that progressed, 15 cases that persisted, and 13 cases that regressed. We analyzed the clonal status of each case by analysis of the pattern of X-chromosomal inactivation. Human papillomavirus (HPV) infection was detected by PCR-RFLP analysis. CINs that are monoclonal or infected by high-risk HPVs are more likely to progress or persist than cases that are polyclonal or negative for high-risk HPVs (p = 0.009 for monoclonal vs polyclonal, p = 0.024 for high-risk HPV positive vs negative p = 0.024). Eighteen (90%) of 20 monoclonal, high-risk HPV-associated CINs progressed or persisted, whereas 9 (60%) of 15 polyclonal or high-risk HPV-negative CINs regressed. Therefore, the combination of clonality status and high-risk type HPV infection was significantly correlated with clinical outcome (p = 0.003). The physical status of the HPV genome was evaluated in 17 cases of HPV-16 positive CINs by real-time PCR. Of those, the HPV viral genome was present in both episomal and integrated forms in 14 CINs (84%), and 12 of these cases (86%) were monoclonal in composition. By contrast, all three CINs in which the HPV genome was present in episomal form were polyclonal. In one CIN1 that was polyclonal, HPV-16 was originally present in episomal form but after 24 months, the patient developed a monoclonal CIN3 in which the HPV-16 genome was present in mixed form. These results may imply that HPV viral integration into the host genomic DNA is associated with progression from polyclonal to monoclonal status in CIN. These events may play a fundamental role in the progression from low-grade to higher grade dysplasia of the cervical mucosa.

Clone Cells↗

Clonal analysis and mutations in the PTEN and the K-ras genes in endometrial hyperplasia.

The patterns of X chromosome inactivation and mutations of PTEN and K-ras were evaluated in cases of endometrial hyperplasia to determine the presence of potentially premalignant neoplastic versus polyclonal benign cell populations. Endometrial glandular epithelial cells were collected by laser capture microdissection, and genomic DNAs were extracted. Following treatment with the methylation sensitive restriction endonuclease Hha I, polymerase chain reaction amplification was performed targeting a highly polymorphic short tandem repeat of the human androgen receptor gene (HUMARA). PTEN and K-ras gene mutations were evaluated by analysis of single-strand conformation polymorphism. Two pathologists performed histologic diagnosis of the lesions independently. Monoclonal composition was demonstrated in 13 of 15 (87%) endometrial hyperplasias with atypia and 17 of 31 (55%) complex hyperplasias without atypia. Cytological atypia is significantly associated with the clonal status of the endometrial hyperplasia (13/15 vs 17/31, P = 0.049). In contrast, all 14 normal endometrial tissue samples were polyclonal. PTEN gene mutations were detected in 4 of 13 (30%) monoclonal endometrial hyperplasias with atypia and 2 of 17 (12%) monoclonal endometrial hyperplasias without atypia but were not detected in polyclonal endometrial hyperplasias, with or without atypia. K-ras gene mutations were present in 3 of 13 (23%) monoclonal endometrial hyperplasias with atypia but not in 2 cases of polyclonal endometrial hyperplasia with atypia or in 26 cases of endometrial hyperplasia without atypia. K-ras mutation is thus significantly more frequently found in endometrial hyperplasias with atypia than those without atypia (3/15 vs 0/31, P = 0.030). This study indicates that most cases of endometrial hyperplasia with atypia and a high proportion of cases of endometrial hyperplasias without atypia originate from a single progenitor cell, possibly as a result of genetic alterations, rather than as a result of benign reactive processes.

Cell Transformation, Neoplastic↗