Biomedical subjects

Shiv Srivastava

Publications and source records attributed to Shiv Srivastava.

28 records · Page 2Linked to original sources

PubMed2002

Androgen-induced expression of endoplasmic reticulum (ER) stress response genes in prostate cancer cells.

Evaluations of androgen regulated gene (ARG) repertoire provide new insights into the androgen receptor (AR) mediated signaling at the transcriptional level. Definition of ARGs having critical functions in the biology of normal and malignant prostate should aid in identifying new bio-markers and therapeutic targets for prostate cancer (CaP). Using Affymetrix HuGene FL oligonucleotide arrays, temporal expression profiles of ARGs in widely used hormone responsive LNCaP cells, were analysed by hierarchical clustering methods and functional classification. ARGs in response to different androgen concentrations showed temporal co-regulation of genes involved in specific biochemical pathways. This study focuses on our new observations of the coordinated androgen induction of genes (NDRG1, PDIR, HERPUD1, ORP150) involved in the endoplasmic reticulum (ER) stress response pathway. Expression analysis of the two selected ER stress responsive genes, NDRG1 and HERPUD1 in primary CaPs revealed a significantly reduced tumor associated expression. Intriguing linkage of the androgen signaling to ER stress responsive genes, a protective response to protein unfolding or protein damage resulting from cellular stress signals, suggests that androgens may induce such stress signals in CaP cells. Decreased CaP associated expression of two ER stress responsive genes also suggests that possible abrogation of this pathway in prostate tumorigenesis.

Androgens↗

PubMed2002

HEPSIN inhibits cell growth/invasion in prostate cancer cells.

Expression of HEPSIN, a type II transmembrane serine protease in prostate cancer (CaP), has been highlighted by several studies analyzing CaP-specific gene expression alterations by cDNA microarray. Evaluations of the biological functions of HEPSIN in CaP cells are warranted for better assessment of its utility as a biomarker and/or therapeutic target. In stable clones of PC-3/HEPSIN transfectants, there was a dramatic reduction in the cell growth, cell invasion, and soft agar colony formation. A higher proportion of PC-3/HEPSIN cells were in the G(2)-M phase of the cell cycle, and there was also an increase in the cell population undergoing apoptosis. Preliminary analysis of HEPSIN transfections into LNCaP and DU145 cells further revealed cell growth-inhibitory effects. These results underscore that exogenous HEPSIN expression negatively regulates cell growth in metastatic CaP cell lines. Although the cause of the biological consequence of HEPSIN overexpression in primary CaP remains to be determined, the negative cell growth-regulatory effects of HEPSIN in metastatic CaP cells reported here have unraveled possible cellular and molecular mechanisms underlying observations that link decreased/loss of HEPSIN expression with poor prognosis of CaP.

3T3 Cells↗

PubMed2002

Molecular markers in prostate cancer: the role in preoperative staging.

Radical prostatectomy as a primary treatment for clinically localized prostate cancer has increased dramatically over the past decade due to prostate-specific antigen (PSA) screening and the awareness of the increased incidence of localized disease. Despite the stage migration to increase clinically localized disease, there are still vast numbers of men who harbor occult extraprostatic extension and develop recurrence after surgery. The study of molecular markers in the blood or tissue of surgical patients prior to treatment, called " molecular staging, " is the focus of this review. The reverse transcriptase- polymerase chain reaction (RT-PCR) test for PSA gene expression in peripheral blood or bone marrow has received considerable attention since its first report in 1992. The test detects messenger RNA species for prostate-specific/abundant genes such as PSA and prostate-specific membrane antigen. These messenger RNAs were not detected in normal blood or bone marrow, but were detected in some prostate cancer patients presumably due to circulating prostatic epithelial cells. These prostate epithelial cells are thought to be occult metastases cells, and early studies correlated a positive RT-PCR test with surgical pathology adverse features such as positive margins. Despite the many studies over the past few years, there have been inconsistent results, and the most recent studies have not been able to confirm clinical utility. Bone marrow RT-PCR has been more promising; however, it is still a research tool that needs further study. The study of molecular markers in tissue material, ie, prostate biopsy samples prior to radical prostatectomy, is problematic due to the sampling error inherent in a multifocal heterogeneous tumor such as prostate cancer. The tumor suppressor proteins p53 and p27, Bcl-2 oncoprotein, Ki-67 proliferation index protein, E-cadherin, and microvessel density have been assessed in preradical prostatectomy needle biopsy. Results have been conflicting, and none are yet accepted as a clinically useful marker. Current and future work is focusing on analysis of multiple gene expressions or proteins simultaneously via gene chip or proteomics technology. While these expression profiles might be of value in whole prostate surgical specimens where tissues are well characterized, it is unclear how this new technology will be applied to the needle biopsy samples. Although molecular staging of radical prostatectomy patients has been under study for a decade, all assays remain research tools. Still, this area holds great promise for improving the accuracy of staging and providing a more accurate prognosis of individual men with clinically localized prostate cancer.

Biomarkers, Tumor↗

PubMed2002

Cadmium-induced neoplastic transformation of human prostate epithelial cells.

Cadmium is a ubiquitous environmental human carcinogen. Epidemiological and animal studies have suggested its carcinogenic potential on the prostate. In the present study, non-tumorigenic human prostate epithelial cells (pRNS-1-1) immortalized by simian papovavirus (SV40) were transformed after repeated exposures to cadmium. Such transformants showed morphological alterations, anchorage-independent growth in soft agar, and formed tumors when transplanted into SCID mice. The tumors were characterized histologically as poorly-differentiated adenocarcinomas, expressing prostate-specific antigen (PSA), androgen receptor (AR), prostate stem cell antigen (PSCA), NKX3.1 and cytokeratin 8 (CK8). These findings provide evidence of malignant transformation of human prostate epithelial cells exposed to this environmentally important chemical.

Adenocarcinoma↗

PubMed2002

Maspin expression profile in human prostate cancer (CaP) and in vitro induction of Maspin expression by androgen ablation.

PURPOSE: Expression of tumor suppressor gene, MASPIN, is associated with inhibition of tumor cell invasion and metastasis. Loss of or decreased expression of Maspin is found frequently in breast and prostate cancer cells. The objective of this study is to investigate Maspin expression in prostate tumor specimens and explore the mechanisms of hormonal regulation of Maspin expression in prostate tumors. EXPERIMENTAL DESIGN: Immunohistochemical staining of Maspin expression was performed on surgical whole-mounted prostate specimens. The expression of Maspin was scored on individual tumors. Correlation of Maspin expression with clinicopathological features was analyzed for statistical significance. Androgen ablation-induced Maspin expression was analyzed by Maspin promoter luciferase reporter assay and quantitative reverse transcription-PCR analysis of endogenous Maspin expression in LNCaP cells in vitro and in animal model. RESULTS: Comprehensive evaluation of Maspin expression profile in multiple tumor foci from whole mounted prostate specimens of prostate cancer patients revealed absence of Maspin expression in a significant fraction (63%). However, Maspin expression is significantly higher in tumor specimens (92%) of patients treated with neoadjuvant androgen ablation therapy before radical prostatectomy. LNCaP cells cultured in androgen-depleted medium show induction of Maspin promoter activity in a promoter luciferase reporter assay. In addition, Maspin expression is increased after castration in LNCaP prostate cancer cells derived tumors in nude mice. CONCLUSIONS: Maspin expression is frequently absent in primary prostate cancers. Up-regulation of MASPIN in response to androgen ablation strongly suggests a physiological role of Maspin in growth inhibition and/or apoptosis of prostate cancer cells during androgen ablation.

Aged↗

PubMed2002

Curcumin down-regulates AR gene expression and activation in prostate cancer cell lines.

Curcumin, traditionally used as a seasoning spice in Indian cuisine, has been reported to decrease the proliferation potential of prostate cancer cells, by a mechanism that is not fully understood. In the current study, we have evaluated the effects of curcumin in cell growth, activation of signal transduction, and transforming activities of both androgen-dependent and independent cell lines. Prostate cancer cell lines, LNCaP and PC-3, were treated with curcumin and its effects were further analyzed on signal transduction and expression of androgen receptor (AR) and AR-related cofactors using transient transfection assay and Western blotting. Our results show that curcumin down-regulates transactivation and expression of AR, activator protein-1 (AP-1), nuclear factor-kappaB (NF-kappaB), and CREB (cAMP response element-binding protein)-binding protein (CBP). Curcumin also inhibited the transforming activities of both cell lines as evidenced by the reduced colony forming ability in soft agar. The results obtained here demonstrate that curcumin has a potential therapeutic effect on prostate cancer cells through down-regulation of AR and AR-related cofactors (AP-1, NF-kappaB and CBP).

Antineoplastic Agents↗

PubMed2002

A human novel gene DERPC on 16q22.1 inhibits prostate tumor cell growth and its expression is decreased in prostate and renal tumors.

BACKGROUND: Deletion of chromosome 16q is frequently associated with diverse tumors. Numerous studies strongly suggest the presence of one or more tumor suppressor genes on chromosome 16q22 to 16qter including the widely studied cadherin gene family. However, the specific tumor suppressor genes residing in this region need better definition and characterization. MATERIAL AND METHODS: Standard molecular biology approaches have been used to clone and characterize the DERPC cDNA and its protein product on chromosome 16q22.1. Northern blotting was used to define the expression pattern in a multiple human tissue blots. DERPC expression was examined in multi-tumor array (Clontech, CA, USA) dot blot as well as in laser capture microdissection (LCM) derived prostate cancer (CaP) specimens by quantitative RT-PCR. Western blot analysis and a fluorescent microscopy were used to characterize the molecular size and the cellular location of green fluorescent protein (GFP)-tagged DERPC fusion proteins. A colony formation assay was conducted to determine the effects of DERPC expression on tumor cell growth. RESULTS: A novel gene DERPC (Decreased Expression in Renal and Prostate Cancer) was identified and characterized. DERPC encoded a strong basic, proline- and glycine-rich nuclear protein. DERPC was ubiquitously expressed, with abundant expression in kidney, skeletal muscle, testis, liver, ovary, and heart and moderate expression in prostate. DERPC expression was reduced in renal (67%) and prostate tumors (33%). Expression of DERPC has inhibitory potential on CaP cell growth. Further, overexpression of DERPC in LNCaP cells caused alterations of nuclear morphology. CONCLUSION: This study suggests that decreased expression of DERPC may be implicated in tumorigenesis of renal and CaPs.

Amino Acid Sequence↗

PubMedDate not supplied

Serum protein expression profiling for cancer detection: validation of a SELDI-based approach for prostate cancer.

Multiple studies have reported that analysis of serum and other bodily fluids using surface enhanced laser desorption/ionization time of flight mass spectroscopy (SELDI-TOF-MS) can identify a "fingerprint" or "signature" of spectral peaks that can separate patients with a specific disease from normal control patients. Ultimately, classification by SELDI-TOF-MS relies on spectral differences in position and amplitude of resolved peaks. Since the reproducibility of quantitation, resolution and mass accuracy of the SELDI-TOF-MS, or any high throughput mass spectrometric technique, has never been determined this method has come under some skepticism as to its clinical usefulness. This manuscript describes a detailed design of a three-phase study to validate the clinical usefulness of SELDI-TOF-MS in the identification of patients with prostatic adenocarcinoma (PCA). At the end of this validation study, the usefulness of the general SELDI-TOF-MS approach to identifying patients with PCA will be demonstrated and how it compares with PCA diagnosis by measuring prostate specific antigen.

Adenocarcinoma↗

PubMedDate not supplied

p63 expression profile in normal and malignant prostate epithelial cells.

p63 expression was evaluated in a tissue microarray of prostate tissues including benign glands, prostatic intraepithelial neoplasia and prostatic carcinoma. Immunostaining with anti-p63 antibody was restricted to basal cell nuclei. Detectable p63 was found in immortalized and early passage cell cultures, but not in senescent cultures or metastatic tumor-derived cell lines. The selective presence of p63 in basal cells of the prostate suggests that p63 can be used as a marker of basal cells and in vitro typing cell cultures of prostate cancer (CaP). The basal cell association underscores its critical functions in the biology of basal cells.

Aged↗

PubMedDate not supplied

Androgen and androgen receptor antagonist responsive primary African-American benign prostate epithelial cell line.

The generation of suitable in vitro models is critical for understanding the process associated with the development and progression of prostate cancer in high-risk African-American men. However, the generation of long-term human prostate epithelial cell lines derived from primary human prostate epithelium have been unsuccessful due to the absence of in vitro immortalization. We have successfully established an immortal human prostate epithelial cell line from primary benign tissues of African-American prostate cancer patients by using telomerase. The actively proliferating secondary African-American prostate epithelial RC-165N cells, derived from benign prostate tissue of a radical prostatectomy specimen, were transduced through infection with a retrovirus vector expressing the human telomerase catalytic subunit (hTERT). A high level of telomerase activity was detected in RC-165N/hTERT cells but not in RC-165N cells. RC-165N/hTERT cells are currently growing well at passage 50 whereas RC-165N cells senesced within passage 3. RC-165N/hTERT cells exhibit epithelial morphology. These immortalized cells showed no cell growth in soft agar, and no tumor formation in SCID mice. The RC-165N/hTERT cells express androgen-regulated prostate-specific homobox gene. NKX 3.1 and epithelial cell specific cytokeratin 8, androgen receptor (AR), prostate stem cell antigen and p16, but not PSA. AR protein was detected by Western blot analysis.

Androgen Antagonists↗