Ki67, PCNA, and MCM proteins: Markers of proliferation in the diagnosis of breast cancer

Peritoneal carcinomatosis of colorectal cancer is characterized by structural and functional reorganization of the tumor microenvironment inducing senescence and proliferation arrest in cancer cells

Background : Peritoneal carcinomatosis (PC) is a terminal evolution from primary colorectal cancer (pCRC) associated with poor patient survival. Impact of the immune cell infiltrate on PC pathogenesis is unknown. Therefore, we characterized the immunological tumor microenvironment regarding proliferation, senescence and neovascularization. Methods : Formalin-fixed and paraffin-embedded (FFPE) tissue of PC and pCRC was examined by immunohistochemistry. Cells infiltrating resected tissue were isolated and analyzed by flow cytometry. PCR arrays detected the expression of genes relevant for helper T (T_H) cell responses, like T_H1, T_H2 and T_H17 response. Results : PC tumor cells demonstrate significantly lower proliferation rates than pCRC, but show significantly more senescence. PC is surrounded by significantly increased numbers of cytotoxic active Natural Killer (NK) cells, follicular helper T cells (T_FH) and B cells, whereas pCRC shows more CD4⁺ T_H cells, CD8⁺ cytotoxic T (T_C) cells, eosinophilic granulocytes, T_H17 and regulatory T (T_reg) cells. PC is characterized by significantly increased interferon-γ (IFNγ), an upregulation of tumor necrosis factor (TNF) and the NK cell-regulating cytokine interleukin-15 (IL-15). An upregulation of angiogenesis-related genes, like vascular endothelial growth factor-A (VEGF-A), leads to severe neovascularization in PC. Correlations of PC results reveal that elevated numbers of interleukin-17 (IL-17) positive cells are associated with high cancer cell proliferation, whereas high numbers of IFNγ positive cells correlate with more tumor cells in senescence. Conclusion : The cellular immune reaction is modified during metastasis, inducing senescence in PC tumor cells. Immune surveillance in PC is facilitated by NK cells and high levels of IFNγ and TNF. Counteracting this effect, T_FH and B cells combined with VEGF-A enhancement promote neovascularization in PC (Illustration 1). During metastasis from primary CRC to PC the immune cell infiltrate changes, accompanied by the induction of senescence in PC cancer cells (marked red): In pCRC, the antitumor immune response is facilitated by CD4⁺T_H cells, CD8⁺T_C cells and PRG2⁺ eosinophilic granulocytes. The premetastatic niche development is promoted by T_reg cells and T_H17 cells producing systemic factors like VEGF-A, TGF-β and TNF. Along with T_FH and B cells, as with a pro-tumor immune response, they support metastatic formation and lead to severe neovascularization in PC. This is counterbalanced by the IL-15-induced activation and proliferation of NK cells. The secreted cytokines IFNγ and TNF mediate immunosurveillance.

Low Dose Cadmium Inhibits Proliferation of Human Renal Mesangial Cells via Activation of the JNK Pathway

Cadmium (Cd) is a heavy metal and environmental pollutant. The kidney is the principal target organ of Cd exposure. Previously, we found that low concentration of Cd damages the integrity of the glomerular filtration barrier. However, little is known about the effects of Cd on renal mesangial cells, which provide structural support for the glomerular capillary loops and regulate intraglomerular blood flow. In this study, human renal mesangial cells (HRMCs) were cultured in the presence of serum and treated with 4 μM Cd. We found that Cd activates the c-Jun N-terminal kinase (JNK) pathway, and increases the protein levels of c-Jun and c-Fos. Cd treatment also induces a decrease in proliferation and an increase in apoptosis of HRMCs, but only the decrease in HRMC proliferation was reversed by pretreatment with SP600125, an inhibitor of the JNK pathway. In addition, Cd does not change the expression of α-smooth muscle actin and platelet-derived growth factor receptor-β, the markers of mesangial cells, or the alignment of the filamentous actin (F-actin) cytoskeleton of HRMCs. Our data indicate that the JNK pathway mediates the inhibitory effects of Cd on HRMC proliferation.

Inhibitory effect of metformin combined with gemcitabine on pancreatic cancer cells in vitro and in vivo

Pancreatic cancer is a malignant digestive system tumor with a particularly poor prognosis, and is the fourth leading cause of cancer-associated mortality in the USA. The anti-diabetic therapeutic agent, metformin (MET) has been demonstrated to exert anti-tumor effects. The present study assessed the ability of MET, alone or in combination with gemcitabine (GEM), to inhibit the growth of the human CFPAC-1 pancreatic cancer cell line in vitro and in vivo. Cell counting kit-8 assays were performed to measure CFPAC-1 cell viability and apoptosis was detected with annexin V/propidium iodide. Cell cycle analysis was conducted by flow cytometry. The mRNA and protein levels of B-cell lymphoma-extra large (Bcl-xL), Bcl2 associated X protein (Bax), caspase-3, survivin and cyclin D1 in CFPAC-1 cells and tumor tissues were detected by reverse transcription-polymerase chain reaction and western blotting, respectively. Furthermore, the expression levels of caspase-3 and proliferating cell nuclear antigen in tumor tissues were detected by immunohistochemistry. The results demonstrated that following MET treatment, the growth of CFPAC-1 cells and xenografts in nude mice was inhibited, the expression levels of Bcl-xL, survivin and cyclin D1 were downregulated, while the expression levels of Bax and caspase-3 were upregulated. These effects were enhanced when MET was administered in combination with GEM. The mechanism underlying the anti-tumor effect of MET may be associated with the induction of cell apoptosis and the inhibition of proliferation.