MiR99a modulates MMP7 and MMP13 to regulate invasiveness of Kaposi’s sarcoma

Helicobacter pylori infection and gastric cancer biology: tempering a double-edged sword

Helicobacter pylori (H. pylori) infection affects an estimated 4.4 billion people globally. Moreover, H. pylori presents the most significant risk factor for gastric cancer and low-grade mucosa-associated lymphoid tissue (MALT) lymphoma, and it is the first example of bacterial infection linked to carcinogenesis. Here, we contend that H. pylori research, which focuses on a cancer-causing pathogen resident in a relatively accessible organ, the stomach, could constitute an exemplar for microbial-related carcinogenesis in less tractable organs, such as the pancreas and lung. In this context, molecular biological approaches that could reap rewards are reviewed, including: (1) gastric cancer dynamics, particularly the role of stem cells and the heterogeneity of neoplastic cells, which are currently being investigated at the single-cell sequencing level; (2) mechanobiology, and the role of three-dimensional organoids and matrix metalloproteases; and (3) the connection between H. pylori and host pathophysiology and the gut microbiome. In the context of H. pylori's contribution to gastric cancer, several important conundrums remain to be fully elucidated. From among them, this article discusses (1) why H. pylori infection, which causes both gastric and duodenal inflammation, is only linked to gastric cancer; (2) whether a "precision oncomicrobiology" approach could enable a fine-tuning of the expression of only cancer-implicated H. pylori genes while maintaining beneficial H. pylori-mediated factors in extra-gastric tissues; and (3) the feasibility of using antibiotics targeting the microbial DNA damage system, which shares commonalities with mechanisms for human cell replication, as chemopreventives. Additional therapeutic perspectives are also discussed.

Micro-RNAs as critical regulators of matrix metalloproteinases in cancer

Metastasis is known to be one of the important factors associated with cancer-related deaths worldwide. Several cellular and molecular targets are involved in the metastasis process. Among these targets, matrix metalloproteinases (MMPs) play central roles in promoting cancer metastasis. MMPs could contribute toward tumor growth, angiogenesis, migration, and invasion via degradation of the extracellular matrix and activation of pre-pro-growth factors. Therefore, identification of various cellular and molecular pathways that affect MMPs could contribute toward a better understanding of the metastatic pathways involved in various tumors. Micro-RNAs are important targets that could affect MMPs. Multiple lines of evidence have indicated that deregulation of various micro-RNAs, including miR-9, Let-7, miR-10b, and miR-15b, affects metastasis of tumor cells via targeting MMPs.

Tauroursodeoxycholic acid reduces the invasion of MDA-MB-231 cells by modulating matrix metalloproteinases 7 and 13

Tauroursodeoxycholic acid (TUDCA) is a conjugated form of UDCA that modulates several signaling pathways and acts as a chemical chaperone to relieve endoplasmic reticulum (ER) stress. The present study showed that TUDCA reduced the invasion of the MDA-MB-231 metastatic breast cancer cell line under normoxic and hypoxic conditions using an in vitro invasion assay. Quantitative polymerase chain reaction assay revealed that the reduced invasion following TUDCA treatment was associated with a decreased expression of matrix metalloproteinase (MMP)-7 and -13, which play important roles in invasion and metastasis. Inhibitors and short hairpin RNAs were used to show that the effect of TUDCA in the reduction of invasion appeared to be dependent on the protein kinase RNA-like ER kinase pathway, a downstream ER stress signaling pathway. Thus, TUDCA is a candidate anti-metastatic agent to target the ER stress pathway.

MicroRNA-454 regulates stromal cell derived factor-1 in the control of the growth of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant carcinoma with an extremely high lethality. We recently reported that hypoxia-inducible factor 1 (HIF-1) targets quiescin sulfhydryl oxidase 1 to facilitate PDAC cell growth and invasion. Here, we analyzed the control of another HIF-1 target, stromal cell derived factor-1 (SDF-1), in PDAC cells. We detected significantly more CD68+ macrophages in the PDAC, compared to normal human pancreas (NT). Since macrophages are recruited to the tissue through their expression of CXCR4 in response to SDF-1, we thus examined the SDF-1 levels in the PDAC specimens. Surprisingly, the SDF-1 protein but not mRNA significantly increased in PDAC, compared to NT. Moreover, a SDF-1-targeting microRNA, miR-454, was found to decrease in PDAC. Promoter luciferase assay confirmed that bindings of miR-454 to 3'-UTR of SDF-1 mRNAs inhibited SDF-1 protein translation. Co-culture of bone marrow derived macrophages and miR-454-modified PDAC cells in a transwell migration experiment showed that macrophages migrated less towards miR-454-overexpressing PDAC cells, and migrated more towards miR-454-depleted cells. Implanted miR-454-depleted PDAC cells grew significantly faster than control, while implanted miR-454-overexpressing PDAC cells grew significantly slower than control. Together, our data suggest that miR-454 may regulate SDF-1 in the control of the growth of PDAC.

Rab11-FIP2 promotes colorectal cancer migration and invasion by regulating PI3K/AKT/MMP7 signaling pathway

Rab11-family interacting proteins (Rab11-FIPs) belong to an evolutionarily conserved protein family and act as effector molecules for the Rab11 family of small GTPases. Recent evidence suggests that Rab11-FIPs have important roles in tumor progression and metastasis. However, the contribution of Rab11-FIPs to colorectal carcinoma (CRC) remains elusive. Our study focuses on elucidating the role of Rab11-FIP2 in the migration and invasion of colorectal cancer cells. We firstly found upregulation of Rab11-FIP2 in CRC tissues compared with peritumor tissues by oncomine data-mining analysis, western blot analysis and immunohistochemistry (IHC) analysis, respectively. Then, we demonstrated that knockdown of Rab11-FIP2 via siRNAs transfection resulted in a decrease in migration and invasion of CRC cells, while overexpression of Rab11-FIP2 via lentiviral infection increased migration and invasion of CRC cells. In addition, we verified that Rab11-FIP2 promoted migration and invasion of CRC cells through upregulating MMP7 expression. Finally, using several kinase inhibitors, our results showed that Rab11-FIP2 regulated MMP7 expression through activating PI3K/Akt signaling. Our data suggested a potential role of Rab11-FIP2 in tumor progression and provided novel insights into the mechanism of how Rab11-FIP2 positively regulated cell migration and invasion in CRC cells.

MiR-130b inhibits proliferation and induces apoptosis of gastric cancer cells via CYLD

A role of microRNA-130b (miR-130b) in the carcinogenesis of gastric cancer remains undetermined. In this study, we studied the effects and mechanism of miR-130b to the gastric cell proliferation and apoptosis. We found that the levels of miR-130b significantly up-regulated in gastric cancer tissue, compared to the paired adjacent non-tumor gastric tissue. The miR-130b levels in gastric cancer cell lines were significantly higher than those in control normal gastric tissues. Transfection with the miR-130b mimic enhanced the cell proliferation and suppressed cell apoptosis in gastric cancer cells, while transfection with the anti-sense of miR-130b (anti-miR-130b) suppressed cell proliferation and induced cell apoptosis in gastric cancer cells. Bioinformatics analyses showed that cylindromatosis gene (CYLD) was a potential target gene of miR-130b. The luciferase activity assay and western blot verified that miR-130b targeted CYLD messenger RNA (mRNA) to modulate its protein levels. Together, our study suggests that aberrantly expressed miR-130b may regulate cell apoptosis and proliferation of human gastric cancer cells via CYLD, which appears to be a promising therapeutic target for gastric cancer.

Pituitary tumor-transforming gene 1 regulates invasion of prostate cancer cells through MMP13

It is critical to understand the molecular mechanisms underlying the migration and invasiveness of prostate cancer (PC) for improving the outcome of therapy. A relationship of pituitary tumor-transforming gene 1 (Pttg1) and matrix metalloproteinase 13 (MMP13) in PC as well as their roles in the metastases of PC has not been studied. Here, we reported significantly higher levels of Pttg1 and MMP13 in the resected PC specimens, compared to the adjacent normal prostate tissue from the same patient. Interestingly, Pttg1 and MMP13 levels strongly correlated with each other. In vitro, Pttg1 activated MMP13, which determined PC cell invasiveness. However, Pttg1 levels were not significantly affected by MMP13. Furthermore, the Pttg1-activated MMP13 in PC cells was significantly suppressed by inhibition of PI3k/Akt, but not ERK/MAPK or JNK pathways. Together, our data suggest that Pttg1 may increase PC cell metastasis by MMP13, and highlight Pttg1/MMP13 axis as a promising therapeutic target for PC treatment.