Rho Kinase Inhibition by AT13148 Blocks Pancreatic Ductal Adenocarcinoma Invasion and Tumor Growth

Upregulated expression of ROCK1 promotes cell proliferation by functioning as a target of miR-335-5p in non-small cell lung cancer

Lung cancer is regarded as one of the dominant causes in cancer patients among men and women all over the world. Rho-associated coiled-coil forming protein kinase l (ROCK1) is characterized as pivotal downstream effectors of the small GTPase RhoA and reported to participate in tumor metastasis. miR-335-5p acts as tumor suppressor microRNA and is identified to be downregulated in tumor tissues. miR-335-5p/ROCK1 axis has been demonstrated to promote cell proliferation and metastasis in gastric cancer, hepatocellular carcinoma and so on. However, the role it plays in promoting cell proliferation in non-small cell lung cancer (NSCLC) is poorly understood. Here, we demonstrated that the upregulated expression of ROCK1 was highly correlated with downregulated expression of miR-335-5p in NSCLC tissues and cell lines. Mechanistically, Knockdown of ROCK1 inhibited cell proliferation in vitro, accompanied by cell cycle change confirmed by flow analysis. Furthermore, miR-335-5p can downregulate the ROCK1 expression by directly binding to the 3'-untranslated region in posttranscriptional level. In vivo animal model showed similar results. Our findings highlighted the crucial role that miR-335-5p acted as a tumor suppressor to modulate cell proliferation and cell cycle progression via downregulating ROCK1 expression. And this miR-335-5p/ROCK1 axis contributed to NSCLC pathogenesis and might be promising targets for NSCLC therapy.

Hypoxia-induced microRNA-141 regulates trophoblast apoptosis, invasion, and vascularization by blocking CXCL12β/CXCR2/4 signal transduction

BACKGROUND

An impaired trophoblast invasion ability contributes to the development of pre-eclampsia (PE), and can be induced by the altered expression of various microRNAs (miRs). MiR-141 and CXCL12β (C-X-C motif chemokine ligand 12) signaling regulate trophoblast invasion and vascularization capabilities during PE pathogenesis; however, their interactions and underlying mechanisms of action remain unclear. We investigated how miR-141 modulates trophoblast invasion, with a focus on its interaction with CXCL12β signaling.

METHODS

A PE model was established by using HTR-8/SVneo cells, which were first cultured with 2% O₂ for 48 h, and then with 5% O₂. The expression of miR-141 in human villous trophoblast HTR-8/SVneo cells was modulated with mimics or an inhibitor, and analyzed by quantitative RT-PCR. CXCL12β levels were determined by ELISA. Cell apoptosis was determined by flow cytometry, and the invasion and vascularization capabilities of trophoblasts were evaluated by Transwell and tube formation assays, respectively. Binding of miR-141 with CXCL12β mRNA was verified by the dual luciferase assay. Protein levels were estimated by western blotting.

RESULTS

MiR-141 expression was significantly induced by hypoxia in HTR-8/SVneo cells. MiR-141 was found to promote apoptosis and inhibit the invasion and vascularization abilities of HTR-8/SVneo cells under conditions of hypoxia. MiR-141 could directly bind with the 3'UTR region of CXCL12β mRNA and inhibit its translation. In addition, we proved that miR-141 could inhibit the invasion and vascularization abilities, and promote the apoptosis of HTR-8/SVneo cells by targeting CXCL12β under hypoxic conditions. Furthermore, we demonstrated that arachidonic acid could reverse the invasion and apoptosis abilities of HTR-8/SVneo cells mediated by CXCL12β during hypoxia. In terms of mechanism, MiR-141 could downregulate MMP2, p62, and LC3B expression, and upregulate ROCK1 and RhoA expression in HTR-8/SVneo cells by targeting the CXCL12β gene during hypoxia. The effects of CXCL12βon HTR-8/SVneo cells could be reversed by arachidonic acid (ARA).

CONCLUSION

Induction of miR-141 by hypoxia promotes apoptosis, and inhibits the invasion and vascularization capabilities of HTR-8/SVneo cells by suppressing the CXCL12β and CXCR2/4 signaling pathways.

Harnessing immune checkpoints in myeloid lineage cells for cancer immunotherapy

Myeloid lineage immune cells, such as macrophages and dendritic cells, play important roles in the induction of antitumor immunity during the initial stage of the cancer-immunity cycle, eliciting antitumor adaptive immunity by phagocytosing cancer cells and processing cancer-specific antigens, and then presenting these antigens to T cells. During this process, cancer cell phagocytosis can be prevented by inhibitory signals, and the signaling cascades that elicit immune responses against cancer antigens can be inhibited by immunosuppressive myeloid cells in the tumor microenvironment. A number of therapeutic strategies for enhancing cancer cell phagocytosis and promoting antitumor immunity by targeting myeloid lineage cells have recently been developed. Here, we discuss recent advances in cancer immunotherapy that involve the targeting of myeloid lineage immune cells to induce effective antitumor immunity.

Myosin II in Cancer Cells Shapes the Immune Microenvironment

Tumor migration is driven by actomyosin contractility. A recent publication by Georgouli et al. (Cell 2019;176:757-774) describes how crosstalk between the cell migration machinery and tumor-associated macrophages (TAMs) shapes the microenvironment to promote tumor growth. Indirectly targeting TAMs by inhibiting the motility of tumor cells could hinder metastatic spread.

Rho–ROCK signaling regulates tumor-microenvironment interactions

Reciprocal biochemical and biophysical interactions between tumor cells, stromal cells and the extracellular matrix (ECM) result in a unique tumor microenvironment that determines disease outcome. The cellular component of the tumor microenvironment contributes to tumor growth by providing nutrients, assisting in the infiltration of immune cells and regulating the production and remodeling of the ECM. The ECM is a noncellular component of the tumor microenvironment and provides both physical and biochemical support to the tumor cells. Rho–ROCK signaling is a key regulator of actomyosin contractility and regulates cell shape, cytoskeletal arrangement and thereby cellular functions such as cell proliferation, differentiation, motility and adhesion. Rho–ROCK signaling has been shown to promote cancer cell growth, migration and invasion. However, it is becoming clear that this pathway also regulates key tumor-promoting properties of the cellular and noncellular components of the tumor microenvironment. There is accumulating evidence that Rho–ROCK signaling enhances ECM stiffness, modifies ECM composition, increases the motility of tumor-associated fibroblasts and lymphocytes and promotes trans-endothelial migration of tumor-associated lymphocytes. In this review, we briefly discuss the current state of knowledge on the role of Rho–ROCK signaling in regulating the tumor microenvironment and the implications of this knowledge for therapy, potentially via the development of selective inhibitors of the components of this pathway to permit the tuning of signaling flux, including one example with demonstrated utility in pre-clinical models.

The Evolving Understanding of the Molecular and Therapeutic Landscape of Pancreatic Ductal Adenocarcinoma

Pancreatic cancer is the third leading cause of cancer-related deaths, characterised by poor survival, marked molecular heterogeneity and high intrinsic and acquired chemoresistance. Only 10⁻20% of pancreatic cancer patients present with surgically resectable disease and even then, 80% die within 5 years. Our increasing understanding of the genomic heterogeneity of cancer suggests that the failure of definitive clinical trials to demonstrate efficacy in the majority of cases is likely due to the low proportion of responsive molecular subtypes. As a consequence, novel treatment strategies to approach this disease are urgently needed. Significant developments in the field of precision oncology have led to increasing molecular stratification of cancers into subtypes, where individual cancers are selected for optimal therapy depending on their molecular or genomic fingerprint. This review provides an overview of the current status of clinically used and emerging treatment strategies, and discusses the advances in and the potential for the implementation of precision medicine in this highly lethal malignancy, for which there are currently no curative systemic therapies.

An Experimenter's Guide to Glioblastoma Invasion Pathways

Glioblastoma is a highly aggressive brain tumor that is characterized by its unparalleled invasiveness. Invasive glioblastoma cells not only escape surgery and focal therapies but also are more resistant to current radio- and chemo-therapeutic approaches. Thus, any curative therapy for this deadly disease likely should include treatment strategies that interfere with glioblastoma invasiveness. Understanding glioblastoma invasion mechanisms is therefore critical. We discuss the strengths and weaknesses of various glioblastoma invasion models and conclude that robust experimental evidence has been obtained for a pro-invasive role of Ephrin receptors, Rho GTPases, and casein kinase 2 (CK2). Extensive interplay occurs between these proteins, suggesting the existence of a glioblastoma invasion signaling network that comprises several targets for therapy.