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Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) 3 is involved in calcium mobilization from the endoplasmic reticulum into the cytosol and is closely linked to metabolism, neuronal plasticity, gene transcription, cell growth, differentiation, apoptosis, protein folding and carcinogenesis. In order to elucidate the role of SERCA3 in colorectal carcinogenesis and subsequent progression, its expression was examined using immunohistochemistry and in situ hybridization (ISH) on tissue microarrays containing colorectal carcinomas, adjacent non-neoplastic mucosa (NNM) and adenoma, and metastatic carcinoma in lymph node and liver. Colorectal carcinoma tissue and cell lines were assessed for SERCA3 expression by western blotting or RT-PCR, respectively. SERCA3 was distinctively expressed in Colo201, Colo205, DLD-1, HCT-15, HCT-116, HT-29, KM-12, SW480, SW620 and WiDr cells at both the mRNA and protein levels. SERCA3 mRNA expression was low in carcinoma when compared to that in matched NNM by quantitative PCR (P0.05), while the converse was true by ISH. Lower expression of SERCA3 was immunohistochemically observed in colorectal carcinoma when compared to that in NNM and adenoma (P0.05). In contrast, primary carcinoma showed high SERCA3 expression when compared to that in metastatic carcinoma in lymph node or liver by IHC (P0.05). Immunohistochemically, SERCA3 expression was negatively related to lymphatic invasion, but not with age, gender, depth of invasion, venous invasion, lymph node metastasis, distant metastasis, TNM stage, degree of differentiation or survival rate (P0.05). There was a positive relationship between SERCA3 expression and serum CEA levels in the carcinoma patients (P0.05). Cox's proportional hazards model indicated that depth of invasion and distant metastasis are independent prognostic factors for overall colorectal carcinomas (P0.05). These findings suggest that aberrant SERCA3 expression is closely linked to the adenoma-adenocarcinoma sequence and progression of colorectal carcinomas.

Background : Parafibromin is a protein encoded by the HRPT2 (hyperparathyroidism 2) oncosuppressor gene and its down-regulated expression is involved in pathogenesis of parathyroid, breast, gastric and colorectal carcinomas. This study aimed to clarify the effects of parafibromin expression on the phenotypes and relevant mechanisms of DLD-1 colon carcinoma cells. Methods: DLD-1 cells transfected with a parafibromin-expressing plasmid were subjected to examination of phenotype, including proliferation, differentiation, apoptosis, migration and invasion. Phenotype-related proteins were measured by Western blot. Parafibromin and ki-67 expression was detected by immunohistochemistry on tissue microarrays. Results: The transfectants showed higher proliferation by CCK-8, better differentiation by electron microscopy and ALP activity and more apoptotic resistance to cisplatin by DNA fragmentation than controls. There was no difference in early apoptosis by annexin V, capase-3 activity, migration and invasion between DLD-1 cells and their transfectants. Ectopic parafibromin expression resulted in down-regulated expression of smad4, MEKK, GRP94, GRP78, GSK3β-ser9, and Caspase-9. However, no difference was detectable in caspase-12 and -8 expression. A positive relationship was noted between parafibromin and ki-67 expression in colorectal carcinoma. Conclusions: Parafibromin overexpression could promote cell proliferation, apoptotic resistance, and differentiation of DLD-1 cells. Keywords: Colon carcinoma cells - parafibromin - cell phenotypes - molecular mechanisms

Background Although its biological function remains poorly understood, REG4 is reported to be a potent activator of the EGFR/Akt/AP-1 signaling pathway in colon cancer cells and closely linked with the inhibition of apoptosis. Methods SKOV3 cells were transfected with a REG4-expressing plasmid or treated with recombinant REG4. We then analyzed proliferation, cell cycle, apoptosis, invasion and metastasis or expression of related molecules. REG4 expression was examined in normal ovarian tissue, benign and borderline tumors, and cancers by immunohistochemistry or real-time PCR. Results REG4 overexpression and the recombinant protein inhibited cell apoptosis, enhanced G2/S progression, proliferation, migration and invasion. Furthermore, expression of Wnt5a, p70s6k, survivin and VEGF expression was increased, while Bax expression was decreased at both the mRNA and protein levels compared to control or mock cells (P

Purpose: Extracellular matrix metalloproteinase inducer (EMMPRIN) was reported to involve in the invasion and metastasis of malignancies by regulating the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) in stromal and cancer cells. The study aimed to clarify the role of EMMPRIN expression in tumorigenesis and progression of ovarian epithelial carcinomas. Methods: EMMPRIN siRNA were transfected into ovarian carcinoma cells with the phenotypes and their related molecules examined. EMMPRIN expression was determined in ovarian normal tissue, benign and borderline tumors, and epithelial carcinomas by real-time PCR, western blot, and immunohistochemisty. Results: EMMPRIN siRNA treatment resulted in a lower growth, G1 arrest, apoptotic induction, decreased migration, and invasion. The transfectants showed reduced expression of Wnt5a, Akt, p70s6k, Bcl-xL, survivin, VEGF, and MMP-9 than mock and control cells at both mRNA and protein levels. According to real-time PCR and western blot, EMMPRIN mRNA or protein level was higher in ovarian borderline tumor and carcinoma than normal ovary and benign tumors (P < 0.05), and positively correlated with dedifferentiation and FIGO staging (P < 0.05). Immuhistochemically, EMMPRIN expression was positively correlated with FIGO staging, dedifferentiation, Ki-67 expression, the lower cumulative and relapse-free survival rate (P < 0.05). Conclusions: Upregulated expression of EMMPRIN protein and mRNA might be involved in the pathogenesis, differentiation, and progression of ovarian carcinomas, possibly by modulating cellular events, such as proliferation, cell cycle, apoptosis, migration, and invasion.