SOCS1 counteracts ROS-mediated survival signals and promotes apoptosis by modulating cell cycle to increase radiosensitivity of colorectal cancer cells

The SOCS-1 -1478CA/del functional polymorphism (rs33989964) is associated with gastric cancer but is unrelated to overall survival

BACKGROUND

In vitro studies have shown that the functional - 1478CA > del polymorphism (rs33989964) of the suppressor of cytokine signaling (SOCS)-1 gene is associated with an altered trascriptional activity. Here, we sought to examine the potential association of this polymorphism with the risk of gastric cancer (GC) and to analyze its prognostic impact on overall survival (OS).

MATERIALS AND METHODS

The study cohort consisted of 74 Turkish patients with GC and 52 healthy controls. Genotyping of the SOCS-1 -1478CA > del polymorphism was carried out using restriction fragment length polymorphism analysis.

RESULTS

After allowance of age and sex, multivariable logistic regression analysis revealed that the carriage of the del allele of the SOCS-1 -1478CA > del polymorphism was independently associated with an increased risk of GC (odds ratio = 6.78, 95% confidence interval = 3.24-10.99, P < 0.001). Kaplan-Meier analysis revealed no significant differences in OS for patients harboring at least one del allele of rs33989964 compared with CA/CA homozygotes (log-rank test, P = 0.17).

CONCLUSION

While the SOCS-1 -1478CA > del polymorphism is significantly associated with the risk of GC in the Turkish population, it does not affect OS.

Targeting Mitochondrial Metabolism to Reverse Radioresistance: An Alternative to Glucose Metabolism

Radiotherapy failure and poor tumor prognosis are primarily attributed to radioresistance. Improving the curative effect of radiotherapy and delaying cancer progression have become difficult problems for clinicians. Glucose metabolism has long been regarded as the main metabolic process by which tumor cells meet their bioenergetic and anabolic needs, with the complex interactions between the mitochondria and tumors being ignored. This misconception was not dispelled until the early 2000s; however, the cellular molecules and signaling pathways involved in radioresistance remain incompletely defined. In addition to being a key metabolic site that regulates tumorigenesis, mitochondria can influence the radiation effects of malignancies by controlling redox reactions, participating in oxidative phosphorylation, producing oncometabolites, and triggering apoptosis. Therefore, the mitochondria are promising targets for the development of novel anticancer drugs. In this review, we summarize the internal relationship and related mechanisms between mitochondrial metabolism and cancer radioresistance, thus exploring the possibility of targeting mitochondrial signaling pathways to reverse radiation insensitivity. We suggest that attention should be paid to the potential value of mitochondria in prolonging the survival of cancer patients.

SOCS3 Attenuates Dexamethasone-Induced M2 Polarization by Down-Regulation of GILZ via ROS- and p38 MAPK-Dependent Pathways

Suppressors of cytokine signaling (SOCS) have emerged as potential regulators of macrophage function. We have investigated mechanisms of SOCS3 action on type 2 macrophage (M2) differentiation induced by glucocorticoid using human monocytic cell lines and mouse bone marrow-derived macrophages. Treatment of THP1 monocytic cells with dexamethasone (Dex) induced ROS generation and M2 polarization promoting IL-10 and TGF-β production, while suppressing IL-1β, TNF-α and IL-6 production. SOCS3 over-expression reduced, whereas SOCS3 ablation enhanced IL-10 and TGF-β induction with concomitant regulation of ROS. As a mediator of M2 differentiation, glucocorticoid-induced leucine zipper (GILZ) was down-regulated by SOCS3 and up-regulated by shSOCS3. The induction of GILZ and IL-10 by Dex was dependent on ROS and p38 MAPK activity. Importantly, GILZ ablation led to the inhibition of ROS generation and anti-inflammatory cytokine induction by Dex. Moreover, GILZ knock-down negated the up-regulation of IL-10 production induced by shSOCS3 transduction. Our data suggest that SOCS3 targets ROS- and p38-dependent GILZ expression to suppress Dex-induced M2 polarization.