Molecular profiling of bladder cancer: involvement of the TGF-beta pathway in bladder cancer progression.

A human bladder cancer model of nine cell sublines derived from the BL17/2 cell line was used to evaluate genes related to disease progression. Molecular profiling of sublines that were non-tumorigenic and invasive in nude mice was performed and identified 1367 differentially-expressed genes. Quantitative real-time PCR analysis of six transforming growth factor-beta (TGF-beta) pathway genes using the entire panel of nine cell lines was performed. Bone morphogenetic protein-2 expression was significantly associated with in vivo tumorigenicity of the cell lines (p=0.0228, Mann-Whitney); inhibin-betaB was related to their invasiveness (p=0.0468, Mann-Whitney). Analysis of conditioned medium showed TGF-beta1 production to be significantly associated with the phenotype of the cell line. The study shows the possible involvement of the TGF-beta pathway in bladder cancer progression.

The role of extracellular matrix metalloproteinase inducer protein in prostate cancer progression.

Extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) is a multifunctional membrane glycoprotein overexpressed in many solid tumors, and involved in tumor invasion and angiogenesis. We investigated EMMPRIN expression in human prostate cancer (CaP) tissues and cells, and evaluated whether EMMPRIN expression is related to tumor progression and matrix metalloproteinase (MMPs) expression in human CaP. An immunohistochemical study using tissue microarrays of 120 primary CaPs of different grades and 20 matched lymph node metastases from untreated patients was performed. The association of EMMPRIN expression with clinicopathological parameters was evaluated. Co-immunolocalization for EMMPRIN and MMP-1, MMP-2 or MMP-9 in primary tumors was examined using confocal microscopy. Flow cytometry and immunoblotting were used to examine EMMPRIN expression in 11 metastatic CaP cell lines. Heterogeneous expression of EMMPRIN was found in 78/120 (65%) CaPs, correlated significantly with progression parameters including pre-treatment PSA level (P < 0.05) and increased with progression of CaP (Gleason score, P < 0.05; pathological stage, P < 0.01; nodal involvement, P < 0.05 and surgical margin, P < 0.05). Heterogeneous cytoplasmic MMP-1, MMP-2 and MMP-9 associated with EMMPRIN immunolabeling was observed, particularly in tumors with Gleason scores >3 + 4. Metastatic CaP cell lines, except DuCaP, expressed abundant EMMPRIN protein, indicating highly ( approximately 45 to approximately 65 kDa) and less ( approximately 30 kDa) glycosylated forms, although with no relationship to cells being either androgen responsive or nonresponsive. Our results suggest that EMMPRIN may regulate MMPs and be involved in CaP progression, and as such, could provide a target for treating metastatic CaP disease.

Plant-derived MINA-05 inhibits human prostate cancer proliferation in vitro and lymph node spread in vivo.

Few treatment options exist for metastatic prostate cancer (PC) that becomes hormone refractory (HRPC). In vitro, plant-derived MINA-05 caused dose-dependent decreases in cell numbers in HRPC cell lines LNCaP-C4-2B and PC-3, and in androgen-sensitive LNCaP-FGC, DuCaP, and LAPC-4, by WST-1 assay. MINA-05 pretreatment significantly decreased clonogenic survival in agar and on plastic at 1 x and 2 x IC50 for PC-3 (P < .05 and P < .001, respectively), and at 1/2 x, 1 x, and 2 x IC50 for LNCaP-FGC cells (P < .001). MINA-05 also induced G2M arrest of LNCaP-FGC and PC-3 cells (by flow cytometry) and caused some apoptosis in LNCaP-FGC (sub-G1 peak on flow, expression of activated caspase-3) but not in PC-3 cells. Western blotting indicated that these cell cycle changes were associated with decreased levels of regulatory proteins cyclin B1 and cdc25C. MINA-05 given daily by gavage for 39 days did not diminish primary orthotopic PC-3 growth in nude mice, but decreased the extent of lymph node invasion at higher doses. We conclude that MINA-05 induces G2M arrest, inhibits cell growth, reduces PC cell regrowth in vitro, and reduces lymph node invasion after orthotopic PC-3 cell implantation in vivo. It has potential as an adjuvant treatment for patients with PC.

Relationship between expression of KAI1 metastasis suppressor gene, mRNA levels and p53 in human bladder and prostate cancer cell lines.

The molecular basis for the loss of KAI1 expression in invasive and metastatic tumors and tumor cell lines is not understood. Recently, identification of a sequence with homology to the consensus p53-binding motif in the promoter of the KAI1 metastasis suppressor gene, has led to a proposal that transcriptional regulation by p53 controls expression of KAI1, and that a dramatic down-regulation of KAI1 mRNA levels in invasive tumors and many tumor cell lines, is directly due to loss of p53 function. We have tested this hypothesis by assessing KAI1 mRNA levels in a series of 22 cell lines derived from bladder and prostate cancers, in which we confirmed the p53 gene sequence and characterized the functional status of the endogenous p53 protein. We anticipated that cell lines expressing p53 capable of transactivation should express high levels of KAI1 mRNA compared with cell lines expressing defective p53, or which were p53-null. KAI1 mRNA levels were determined by northern analysis using a full-length KAI1 cDNA probe, and varied widely between cell lines examined. However, there was no association between these levels and p53 status. Furthermore, transfection of representative cell lines with wild-type p53, or exposure to DNA damaging agents, had no effect on KAI1 mRNA levels. Our data suggest that p53 is not a major factor regulating levels of KAI1 mRNA in bladder and prostate cancer cell lines.

Correlation of Histocompatibility Reactions with Fusion Between Conspecifics in the Solitary Urochordate Styela plicata.

Previous transplantation analysis has identified a sensitive histocompatibility system in the solitary urochordate Styela plicata that obeys genetic transplantation "rules" identical to those of vertebrates. The current study demonstrates that histocompatibility acts to prevent fusion between conspecifics in sedentary aggregations of this species. Pairs of naturally fused individuals were present at low frequencies (0.06%) in natural populations. Comparative transplantation analysis, in which grafts were transferred from fused donors to panels of single (non-paired) recipients, confirmed that such fusion occurs only between individuals of identical histocompatibility tissue type. Ninety-four percent of recipients yielded identical responses to allografts from both members of fused pairs, suggesting that fused individuals expressed concordant histocompatibility tissue types. In contrast, only 69% of hosts receiving allografts from pairs of randomly selected unfused individuals yielded identical responses to both donor tissues. Allozyme analysis confirmed the specificity of this correlation between fusion and shared histocompatibility type. Fused individuals retained distinct genetic identities for electrophoretically resolved loci independent of tissue type. In light of these results, it is argued that the role of histocompatibility systems in preventing fusion may have been a strong selective force in the evolution of allogeneic recognition.