GRK3 is essential for metastatic cells and promotes prostate tumor progression.

The biochemical mechanisms that regulate the process of cancer metastasis are still poorly understood. Because kinases, and the signaling pathways they comprise, play key roles in regulation of many cellular processes, we used an unbiased RNAi in vitro screen and a focused cDNA in vivo screen against human kinases to identify those with previously undocumented roles in metastasis. We discovered that G-protein-coupled receptor kinase 3 (GRK3; or ß-adrenergic receptor kinase 2) was not only necessary for survival and proliferation of metastatic cells, but also sufficient to promote primary prostate tumor growth and metastasis upon exogenous expression in poorly metastatic cells in mouse xenograft models. Mechanistically, we found that GRK3 stimulated angiogenesis, at least in part through down-regulation of thrombospondin-1 and plasminogen activator inhibitor type 2. Furthermore, GRK3 was found to be overexpressed in human prostate cancers, especially in metastatic tumors. Taken together, these data suggest that GRK3 plays an important role in prostate cancer progression and metastasis.

Prosaposin inhibits tumor metastasis via paracrine and endocrine stimulation of stromal p53 and Tsp-1.

Metastatic tumors can prepare a distant site for colonization via the secretion of factors that act in a systemic manner. We hypothesized that non- or weakly metastatic human tumor cells may act in an opposite fashion by creating a microenvironment in distant tissues that is refractory to colonization. By comparing cell lines with different metastatic potential, we have identified a tumor-secreted inhibitor of metastasis, prosaposin (Psap), which functions in a paracrine and endocrine fashion by stimulating the expression of thrombospondin-1 (Tsp-1) in fibroblasts present in both primary tumors and distant organs, doing so in a p53-dependent manner. Introduction of Psap in highly metastatic cells significantly reduced the occurrence of metastases, whereas inhibition of Psap production by tumor cells was associated with increased metastatic frequency. In human prostate cancer, decreased Psap expression was significantly associated with metastatic tumors. Our findings suggest that prosaposin, or other agents that stimulate p53 activity in the tumor stroma, may be an effective therapy by inhibition of the metastatic process.

Disordered structure and function of liver in HIV/AIDS--a study of thirty cases.

To study abnormalities in liver associated enzymes and histology in AIDS patients with common infections like hepatotrophic viruses and mycobacteria. 30 cases of HIV/AIDS were studied for any significant pattern emerging. The male:female ratio was 4.26:1, occupation being long-distance truck drivers (30%); migrant goldsmiths (27%); migrant labourers (24%). Duration of illness from onset was within three months (46%) and the maximum duration was 26 months (2%). The most common presentation was fever (90%), weakness (79%), weight loss (62%) and diarrhoea (62%). The CD4 cell count was between 200-500/microL (33%). LFT showed hyperglobulinemia in patients having CD4 cell count <500/microL. Rise of alkaline phosphatase was seen in 63% with CD4 cell count <200/microL. 66.6% had HBsAg reactivity, 33.3% had positive anti-HCV antibody and 50% had abnormal liver histology. One third of these had systemic opportunistic infections like tuberculosis. No correlation could be made between hepatic histology and LFT.

No association between seropositivity for hepatitis C virus and lichen planus: a case control study.

BACKGROUND: The epidemiological association of lichen planus (LP) with hepatitis C virus (HCV) infection has been recorded from some countries and HCV RNA3 has been isolated from lesional skin in patients with LP and chronic HCV infection. The observed geographical differences regarding HCV infection and LP could be immuno-genetically related. AIM: To determine whether HCV has a causal relationship with LP. METHODS: Histopathologically proved cases of LP were subjected to antibody to HCV test by the Third Generation Enzyme Immunoassay Kit for the detection of antibody to HCV (Anti-HCV) in human serum or plasma. They were routinely screened in the virology department by the reagent kit, HIVASE 1 + 2, adopting the "direct sandwich principle" for the assay to detect antibodies to HIV-1 and/or HIV-2. There were 150 age and sex matched controls (not suffering from LP) and HIV-I and II negative, and negative for HCV. RESULTS: Of the 104 patients studied only 2 patients (1.92%) of generalized LP with disease duration of more than 3 months were found to be positive for antibodies to HCV. This was not a significant finding and no statistical methods, e.g. Chi square test etc. could be applied. CONCLUSION: Hepatitis C virus is not significant to the causation of LP in India.

Fatty acid synthase expression defines distinct molecular signatures in prostate cancer.

The androgen-regulated enzyme fatty acid synthase (FAS), required for de novo lipogenesis, is overexpressed in several cancers including prostate carcinoma and has been associated with aggressive disease. FAS expression was assessed in 81 prostate carcinomas, both by immunohistochemistry in tissue microarrays and by Affymetrix Hu95Av2 oligonucleotide arrays. Both FAS mRNA and protein were significantly overexpressed in prostate carcinomas compared with the corresponding normal tissue. FAS mRNA and protein expression increased substantially from normal to prostatic intraepithelial neoplasia, to low grade, to high grade, and to androgen-independent bone metastases. A significant correlation between FAS mRNA and protein expression was found in two thirds of the cases. In 17% of the cases, FAS protein levels were high despite low mRNA levels, and these tumors exhibited a distinct molecular signature when compared with tumors that did not express FAS protein. Whereas the latter group of tumors expressed some proapoptotic genes, tumors with high FAS levels overexpressed, among other genes, its transcriptional regulator, steroid regulator binding protein, and apolipoprotein E. These data demonstrate (1) the consistent overexpression of FAS in prostate carcinoma compared with the adjacent normal tissue, (2) a strong association between FAS and prostate tumor initiation and progression, (3) the highest FAS expression occurring in androgen-independent bone metastases, (4) the transcriptional and posttranscriptional regulation of FAS in the majority and in a subset of prostate cancers, respectively, and (5) most importantly, the identification by FAS expression of prostate tumors with unique molecular signatures and potentially diverse biologic behavior.

A phase II clinical and pharmacodynamic study of E7070 in patients with metastatic, recurrent, or refractory squamous cell carcinoma of the head and neck: modulation of retinoblastoma protein phosphorylation by a novel chloroindolyl sulfonamide cell cycle inhibitor.

PURPOSE: E7070 is a synthetic sulfonamide cell cycle inhibitor that induces hypophosphorylation of the retinoblastoma (Rb) protein and G(1) arrest in vitro. This Phase II study was conducted to explore the efficacy, safety, and pharmacodynamics of E7070 in squamous cell carcinoma of the head and neck (SCCHN). EXPERIMENTAL DESIGN: Patients with metastatic, recurrent, or refractory SCCHN, treated with no more than one prior therapy for recurrent disease, received E7070 at 700 mg/m(2) over 1 h every 3 weeks. Pre- and posttreatment tumor fine needle aspirates were subjected to immunohistochemistry with a panel of phospho-specific anti-Rb antibodies. End points included progression-free survival, response rate and duration, overall survival, toxicity profile, and inhibition of Rb phosphorylation. RESULTS: Because none of the first 15 patients achieved progression-free survival > 4 months, the early stopping rule was invoked. Eleven patients had oropharyngeal cancer and 12 were male. Median age was 59 years (range, 49-73 years). Thirty-nine cycles of E7070 were delivered (median, 2.6 cycles/patient; range, 1-5 cycles). Six patients had stable disease after 2 cycles and 2 patients each subsequently received 1, 2, and 3 additional cycles, respectively, before experiencing progression. Immunohistochemistry of tumor cell aspirates from 3 patients demonstrated reduced Rb phosphorylation posttreatment. CONCLUSIONS: At this dose and schedule, E7070 is unlikely to be superior over single-agent chemotherapy in SCCHN. However, the data suggest that cdk activity can be inhibited in tumor cells, resulting in posttreatment modulation of Rb phosphorylation. In the absence of cytotoxicity, more frequent administration of E7070 may be required to sustain Rb hypophosphorylation and cytostatic growth arrest.

First report in India of HIV transmission through artificial insemination.

A case of HIV-1 transmission through artificial inseminations from infertility clinics in Kolkata, is reported.

Bone marrow-derived Gr1+ cells can generate a metastasis-resistant microenvironment via induced secretion of thrombospondin-1.

UNLABELLED: Metastatic tumors have been shown to establish permissive microenvironments for metastases via recruitment of bone marrow-derived cells. Here, we show that metastasis-incompetent tumors are also capable of generating such microenvironments. However, in these situations, the otherwise prometastatic Gr1(+) myeloid cells create a metastasis-refractory microenvironment via the induction of thrombospondin-1 (Tsp-1) by tumor-secreted prosaposin. Bone marrow-specific genetic deletion of Tsp-1 abolished the inhibition of metastasis, which was restored by bone marrow transplant from Tsp-1(+) donors. We also developed a 5-amino acid peptide from prosaposin as a pharmacologic inducer of Tsp-1 in Gr1(+) bone marrow cells, which dramatically suppressed metastasis. These results provide mechanistic insights into why certain tumors are deficient in metastatic potential and implicate recruited Gr1(+) myeloid cells as the main source of Tsp-1. The results underscore the plasticity of Gr1(+) cells, which, depending on the context, promote or inhibit metastasis, and suggest that the peptide could be a potential therapeutic agent against metastatic cancer. SIGNIFICANCE: The mechanisms of metastasis suppression are poorly understood. Here, we have identified a novel mechanism whereby metastasis-incompetent tumors generate metastasis-suppressive microenvironments in distant organs by inducing Tsp-1 expression in the bone marrow­derived Gr1+myeloid cells. A 5-amino acid peptide with Tsp-1­inducing activity was identified as a therapeutic agent against metastatic cancer.

Platelet-associated PF-4 as a biomarker of early tumor growth.

Early tumor detection and intervention are important determinants of survival in patients with cancer. We have recently reported that the "platelet angiogenesis proteome" may be used to detect microscopic tumors in mice. We now present evidence that changes in platelet-associated platelet factor-4 (PF-4) detect malignant growth across a spectrum of human cancers in mice. A deregulated expression of an 8206-Da protein was observed by surfaceenhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-ToF MS) proteomic comparison of platelets from normal and tumor-bearing mice. The differentially expressed protein was identified as PF-4 by tandem mass spectrometry and ProteinChip immunoassay using anti-PF-4 antibody. The platelet-associated PF-4 appeared to be up-regulated in early growth of human liposarcoma, mammary adenocarcinoma, and osteosarcoma. A 120-day follow-up study of liposarcoma revealed a sustained 2-fold or higher increase of platelet-associated PF-4 at 19, 30, and 120 days. In contrast, only an insignificant change of PF-4 was observed in the plasma of mice bearing the different human tumor xenografts, and throughout the 120 days of the liposarcoma study. We conclude that platelet-associated PF-4, but not its plasma counterpart, may represent a potential biomarker of early tumor presence.

Erythropoietin stimulates growth and STAT5 phosphorylation in human prostate epithelial and prostate cancer cells.

BACKGROUND: Erythropoietin (Epo), the principal regulator of erythroid progenitor survival, growth, and differentiation, initiates its action by binding to its cognate cell surface receptor (EpoR). EpoR have been identified on a variety of non-hematopoietic cells, both normal and malignant, however, little is known about the function of EpoR on malignant cells. METHODS: RT-PCR, Western blotting, and immunohistochemistry were used to demonstrate that prostate cancer cells express EpoR at both the gene and protein level. Cell proliferation assays and STAT5 phosphorylation were used to demonstrate Epo's mitogenic action and intracellular signaling, respectively. RESULTS: We have demonstrated that transformed prostate epithelial and prostate cancer cell lines, as well as primary prostate tissue, express the EpoR. Importantly, the EpoR on prostate cells are functional, as demonstrated by the observation that each of the cell lines exhibited a dose-dependent proliferative response to Epo, and that Epo triggered STAT5b phosphorylation in the cells. CONCLUSION: Human prostatic epithelial cells and prostate cancer cells express functional EpoR, and Epo serves as a growth factor for these cells. These results have implications for our understanding of normal prostatic growth and development and of the pathobiology of human prostate cancer.

Leiomyomatosis peritonealis disseminata--a rare case report.

An infertile female aged 34 years was admitted with an abdominopelvic lump of 16 weeks size. On laparotomy innumerable nodular seedlings, in addition to uterine fibroid, simulating disseminated intra-abdominal malignancy were found. Histopathology of removed specimen of uterus and omentum revealed leiomyomatosis peritonealis disseminata.

Intermediate basal cells of the prostate: in vitro and in vivo characterization.

BACKGROUND: Progenitor cells within the prostate basal layer may play important roles in differentiation and carcinogenesis; however, prostate stem cell populations remain uncharacterized. METHODS: Immunohistochemical and immunoblot analyses were used to characterize prostate epithelial cells (PrEC), a commercially available prostate basal cell isolate. RESULTS: Proliferating PrECs exhibited immunophenotypic characteristics most consistent with basal cells, but during senescence PrECs up-regulated androgen receptor (AR) mRNA, p27, and low-molecular-weight cytokeratin (LMWCK) expression, suggestive of partial differentiation. PrECs also stained strongly for involucrin, which marked a subset of intermediate prostate basal cells in vivo. Basal hyperplasia consisting of involucrin-positive cells was prevalent in prostate tissue from androgen-ablated patients, and formed epithelial clusters flanked by involucrin-negative basal and luminal monolayers. Cultivation of PrECs on matrigel together with androgen-treated stromal conditioned media resulted in dense aggregates, with a peripheral rim of basal-like cells expressing p63 and basal cytokeratins. CONCLUSIONS: PrEC represents an epithelial population whose basal characteristics are modified in response to matrigel, stromal factors, and senescence, consistent with a transient amplifying population. These cells may derive from a previously unrecognized, involucrin-positive subset present in vivo.