DAB2IP stabilizes p27Kip1 via suppressing PI3K/AKT signaling in clear cell renal cell carcinoma

An update on the tumor-suppressive functions of the RasGAP protein DAB2IP with focus on therapeutic implications

The dynamic crosstalk between tumor and stromal cells is a major determinant of cancer aggressiveness. The tumor-suppressor DAB2IP (Disabled homolog 2 interacting protein) plays an important role in this context, since it modulates cell responses to multiple extracellular inputs, including inflammatory cytokines and growth factors. DAB2IP is a RasGAP and negatively controls Ras-dependent mitogenic signals. In addition, it modulates other major oncogenic pathways, including TNFα/NF-κB, WNT/β-catenin, PI3K/AKT, and androgen receptor signaling. In line with its tumor-suppressive role, DAB2IP is frequently inactivated in cancer by transcriptional and post-transcriptional mechanisms, including promoter methylation, microRNA-mediated downregulation, and protein-protein interactions. Intriguingly, some observations suggest that downregulation of DAB2IP in cells of the tumor stroma could foster establishment of a pro-metastatic microenvironment. This review summarizes recent insights into the tumor-suppressive functions of DAB2IP and the consequences of its inactivation in cancer. In particular, we explore potential approaches aimed at reactivating DAB2IP, or augmenting its expression levels, as a novel strategy in cancer treatment. We suggest that reactivation or upregulation of DAB2IP would concurrently attenuate multiple oncogenic pathways in both cancer cells and the tumor microenvironment, with implications for improved treatment of a broad spectrum of tumors.

DAB2IP inhibits glucose uptake by modulating HIF-1α ubiquitination under hypoxia in breast cancer

Metabolic reprogramming has become increasingly important in tumor biology research. The glucose metabolic pathway is a major energy source and is often dysregulated in breast cancer. DAB2IP is widely reported to be a tumor suppressor that acts as a scaffold protein to suppress tumor malignancy in breast cancer. Interestingly, DAB2IP has also been found to be a potential regulator of glucose uptake; however, the exact mechanism remains unclear. In this study, we found that DAB2IP inhibited glucose uptake under hypoxia conditions in breast cancer cells by suppressing HIF-1α signals. Mechanically, DAB2IP interacted with the E3 ubiquitin ligase STUB1 via its PER domain, thus triggering STUB1 mediated HIF-1α ubiquitylation and degradation, and inhibit glucose metabolism and tumor progression. Deleting the PER domain abrogated the DAB2IP-related inhibitory effects on glucose uptake, intracellular ATP production, and lactic acid production in breast cancer cells. These findings elucidate the biological roles of DAB2IP in cancer-related glucose metabolism as well as a novel mechanism by which STUB1-driven HIF-1α ubiquitylated degradation is regulated in breast cancer.

Analyzing the Antihyperglycemic Effect of Cissus quadrangularis and Bacopa monnieri on 3T3-L1 Cell Lines

Background Cissus quadrangularis is a perennial shrub of the grape family. Other names for it include devil's backbone, veld grape, and pirandai (Tamil). Bacopa monnieri, a perennial plant, is native to wetlands in eastern and southern India. The 3T3-L1 cell line, which was created from 3T3 cells, was used in the scientific study. The current study's purpose is to evaluate the antihyperglycemic benefits of B. monnieri and C. quadrangularis, which will be added to the current arsenal of efficient herbal hypoglycemic medications. Aim To analyze and compare the anti-hyperglycaemic effects of the two plant extracts, C. quadrangularis and B. monnieri using a 3T3-L1 cell line. Materials and methods C. quadrangularis seeds were gathered, and extraction was conducted. The B. monnieri plant was harvested, and a rotary evaporator was used to extract the flower. Adipocyte cells were obtained from NCCS, Pune. A CO2 incubator was used to incubate the cells. The MTT assay and gene expression analysis were done on the cell line samples. Results The antihyperglycemic effects of C. quadrangularis IRS mRNA levels of 0.7 and AKT mRNA levels of 0.7 are compared to B. monnieri IRS1 mRNA levels of 0.6 and AKT mRNA levels of 0.6 to build better diabetic treatments. The antihyperglycemic benefits of C. quadrangularis levels of IRS mRNA and AKT mRNA are compared to the influence of B. monnieri IRS1 mRNA and AKT mRNA on the development of better diabetic drugs. Conclusion Comparing the effects of C. quadrangularis and B. monnieri on the 3T3 cell line by gene expression of IRS mRNA and AKT mRNA suggests that the particular AKT downregulation shows that insulin suppresses gluconeogenesis and C. quadrangularis inhibits hyperglycemia in 3T3-L1 cells, while research on in vitro rats suggests that B. monnieri may minimize the signs and symptoms of diabetes via enhancing IRS1/AKT signaling.