From the morphological point of view, the dysplasia-carcinoma sequence is the most plausible carcinogenic pathway for gallbladder cancer, a process which would require a period of approximately 10 years.

Background Gastric cancer (GC) is a deadly malignancy worldwide. In the past, it has been shown that cellular signaling pathway alterations play a crucial role in the development of GC. In particular, deregulation of the PI3K/AKT/mTOR pathway seems to affect multiple GC functions including growth, proliferation, metabolism, motility and angiogenesis. Targeting alterations in this pathway by microRNAs (miRNAs) represents a potential therapeutic strategy, especially in inhibitor-resistant tumors. The objective of this study was to evaluate the expression of 3 pre-selected miRNAs, miR-101-2, miR-125b-2 and miR-451a, in a series of primary GC tissues and matched non-GC tissues and in several GC-derived cell lines, and to subsequently evaluate the functional role of these miRNAs. Methods Twenty-five primary GC samples, 25 matched non-GC samples and 3 GC-derived cell lines, i.e., AGS, MKN28 and MKN45, were included in this study. miRNA and target gene expression levels were assessed by quantitative RT-PCR and western blotting, respectively. Subsequently, cell viability, clone formation, cell death, migration and invasion assays were performed on AGS cells. Results miR-101-2, miR-125b-2 and miR-451a were found to be down-regulated in the primary GC tissues and the GC-derived cell lines tested. MiRNA mimic transfections significantly reduced cell viability and colony formation, increased cell death and reduced cell migration and invasion in AGS cells. We also found that exogenous expression of miR-101-2, miR-125b-2 and miR-451a decreased the expression of their putative targets MTOR, PIK3CB and TSC1, respectively. Conclusions Our expression analyses and in vitro functional assays suggest that miR-101-2, miR-125b-2 and miR-451a act as potential tumor suppressors in primary GCs as well as in GC-derived AGS cells.

The PI3K/AKT/mTOR pathway plays a crucial role in the regulation of multiple cellular functions including cell growth, proliferation, metabolism and angiogenesis. Emerging evidence has shown that deregulation of this pathway has a role promoting gastric cancer (GC). The aim was to assess the expression of genes involved in this pathway by qPCR in 23 tumor and 23 non-tumor gastric mucosa samples from advanced GC patients, and in AGS, MKN28 and MKN45 gastric cancer cell lines. Results showed a slight overexpression of PIK3CA, PIK3CB, AKT1, MTOR, RPS6KB1, EIF4EBP1 and EIF4E genes, and a slightly decreased PTEN and TSC1 expression. In AGS, MKN28 and MKN45 cells a significant gene overexpression of PIK3CA, PIK3CB, AKT1, MTOR, RPS6KB1 and EIF4E, and a significant repression of PTEN gene expression were observed. Immunoblotting showed that PI3K-β, AKT, p-AKT, PTEN, mTOR, p-mTOR, P70S6K1, p-P70S6K1, 4E-BP1, p-4E-BP1, eIF4E and p-eIF4E proteins were present in cell lines at different levels, confirming activation of this pathway in vitro. This is the first time this extensive panel of 9 genes within PI3K/AKT/mTOR pathway has been studied in GC to clarify the biological role of this pathway in GC and develop new strategies for this malignancy.

Most gallbladder cancer (GBC) cases arise in the context of gallstones, which cause inflammation, but few gallstone patients develop GBC. We explored inflammation/immune-related markers measured in bile and serum in GBC cases compared to gallstone patients to better understand how inflammatory patterns in these two conditions differ. We measured 65 immune-related markers in serum and bile from 41 GBC cases and 127 gallstone patients from Shanghai, China, and calculated age- and sex-adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for GBC versus gallstones. We then focused on the markers that were significantly elevated in bile and serum to replicate in serum from 35 GBC cases and 31 gallstone controls from Chile. Comparing the highest versus lowest quantile, 15 markers (23%) were elevated in both serum and bile from GBC versus gallstone patients in the Shanghai study (p<0.05). The strongest OR was for CXCL8 (interleukin-8) in serum (96.8, 95% CI: 11.9–790.2). Of these 15 markers, 6 were also significantly elevated in serum from Chile (CCL20, C-reactive protein, CXCL8, CXCL10, resistin, serum amyloid A). Pooled ORs from Shanghai and Chile for these 6 markers ranged from 7.2 (95% CI: 2.8–18.4) for CXCL10 to 58.2 (95% CI: 12.4–273.0) for CXCL8. GBC is associated with inflammation above and beyond that generated by gallstones alone. This local inflammatory process is reflected systemically. Future longitudinal studies are needed to identify the key players in cancer development, which may guide translational efforts to identify individuals at high risk of developing GBC.