Aurora kinase A inhibition induces synthetic lethality in SMAD4-deficient colorectal cancer cells via spindle assembly checkpoint activation

AURKA knockdown inhibits esophageal squamous cell carcinoma progression through ferroptosis

Aurora kinase A, as a pro-carcinogenic in gastric cancer and glioma kinase, is enhanced in several human tumors. However, it's regulatory mechanism in esophageal squamous cell carcinoma (ESCC) remains unclear. Thus, this study aimed to investigate the expression status, functional roles, and molecular mechanisms of AURKA in ESCC development. AURKA expression was analyzed by the screening of the GEO database and detected using an immunohistochemical method. The biological function of AURKA on ESCC was evaluated in vitro and in vivo. Western blot assay, malondialdehyde (MDA), iron, and glutathione (GSH) kits were utilized to assess changes in ferroptosis. Database analysis results showed that AURKA was a differential gene in ESCC and was highly expressed in human ESCC tissues. Functionally, AURKA knockdown decreased ESCC cell proliferation, invasion, and metastasis both in vitro and in vivo. Moreover, when AURKA was knockdown, cells were more correctly blocked in the G2/M phase, and the ferroptosis-related MDA and Fe increased, whereas the GSH reduced. Consistently, Glutathione peroxidase 4 (GPX4) and solute carrier family 7a member 11 (SLC7A11) expression were downregulated by AURKA knockdown. However, ferroptosis inhibitor partially restore ESCC cell proliferation, invasion, and metastasis caused by AURKA knockdown. AURKA knockdown enhances ferroptosis and acts against cancer progression in ESCC. AURKA acts as a tumor-promoting gene and may serve as potential target for ESCC treatment.

Genome-wide CRISPR Screen Reveals RAB10 as a Synthetic Lethal Gene in Colorectal and Pancreatic Cancers Carrying SMAD4 Loss

The TGFβ signaling mediator SMAD4 is frequently mutated or deleted in colorectal and pancreatic cancers. SMAD4 acts as a tumor suppressor and its loss is associated with poorer patient outcomes. The purpose of this study was to find synthetic lethal interactions with SMAD4 deficiency to find novel therapeutic strategies for the treatment of patients with SMAD4-deficient colorectal or pancreatic cancers. Using pooled lentiviral single-guide RNA libraries, we conducted genome-wide loss-of-function screens in Cas9-expressing colorectal and pancreatic cancer cells harboring altered or wild-type SMAD4. The small GTPase protein RAB10 was identified and validated as a susceptibility gene in SMAD4-altered colorectal and pancreatic cancer cells. Rescue assays showed that RAB10 reintroduction reversed the antiproliferative effects of RAB10 knockout in SMAD4-negative cell lines. Further investigation is necessary to shed light on the mechanism by which RAB10 inhibition decreases cell proliferation of SMAD4-negative cells.

Significance

This study identified and validated RAB10 as new synthetic lethal gene with SMAD4. This was achieved by conducting a whole-genome CRISPR screens in different colorectal and pancreatic cell lines. A future RAB10 inhibitors could correspond to a new therapeutic solution for patients with cancer with SMAD4 deletion.

Chebulagic acid suppresses gastric cancer by inhibiting the AURKA/β-catenin/Wnt pathway

Gastric cancer (GC) is a prevalent malignant neoplasm that poses a serious threat to human health. Overexpression of Aurora A (AURKA) is frequently associated with the self-renewal and tumorigenicity of various cancers. Chebulagic acid (CA) has been examined as a potential tumor suppressor based on its ability against numerous tumor biological activities. However, the possible mechanisms of CA inhibition of the progression of GC by mediating the AURKA/β-catenin/Wnt signaling pathway have not been investigated. The present study investigated the level of AURKA expression in GC. We further examined the effect of CA on cell proliferation, migration, and apoptosis in the MKN1 and NUGC3 GC cell lines, and its efficacy in suppressing tumor growth was assessed in tumor bearing mice model. We demonstrated that AURKA was highly expressed in GC and associated with poor prognosis. We demonstrated that treatment with CA significantly inhibited the proliferation and migration of GC cells and induced apoptosis. Compared to the vehicle group, CA treatment severely diminished the volume and weight and the metastasis of tumors. CA also inhibited the expression of AURKA and the AURKA/β-catenin/Wnt signaling pathway in vitro and in vivo. Collectively, the present results demonstrated that high expression of AURKA may be an independent factor of poor prognosis in patients with GC, and CA significantly suppressed the tumor biological functions of GC and inhibited the AURKA/β-catenin/Wnt pathway.

Co-inhibition of Aurora A and Haspin kinases enhances survivin blockage and p53 induction for mitotic catastrophe and apoptosis in human colorectal cancer

Colorectal cancer (CRC) is a leading cause and mortality worldwide. Aurora A and haspin kinases act pivotal roles in mitotic progression. However, the blockage of Aurora A and Haspin for CRC therapy is still unclear. Here we show that the Haspin and p-H3T3 protein levels were highly expressed in CRC tumor tissues of clinical patients. Overexpression of Haspin increased the protein levels of p-H3T3 and survivin in human CRC cells; conversely, the protein levels of p-H3T3 and survivin were decreased by the Haspin gene knockdown. Moreover, the gene knockdown of Aurora A induced abnormal chromosome segregation, mitotic catastrophe, and cell growth inhibition. Combined targeted by co-treatment of CHR6494, a Haspin inhibitor, and MLN8237, an Aurora A inhibitor, enhanced apoptosis and CRC tumor inhibition. MLN8237 and CHR6494 induced abnormal chromosome segregation and mitotic catastrophe. Meanwhile, MLN8237 and CHR6494 inhibited survivin protein levels but conversely induced p53 protein expression. Ectopic survivin expression by transfection with a survivin-expressed vector resisted the cell death in the MLN8237- and CHR6494-treated cells. In contrast, the existence of functional p53 increased the apoptotic levels by treatment with MLN8237 and CHR6494. Co-treatment of CHR6494 and MLN8237 enhanced the blockage of human CRC xenograft tumors in nude mice. Taken together, co-inhibition of Aurora A and Haspin enhances survivin inhibition, p53 pathway induction, mitotic catastrophe, apoptosis and tumor inhibition that may provide a potential strategy for CRC therapy.