JAK1 inactivation promotes proliferation and migration of endometrial cancer cells via upregulating the hypoxia-inducible factor signaling pathway

Cardiovascular, cancer, and infection risks of Janus kinase inhibitors in rheumatoid arthritis and ulcerative colitis: A nationwide cohort study

BACKGROUND

Evolving evidence suggests that patients undergoing treatment with Janus kinase inhibitors (JAKi) may face an increased risk of cardiovascular events, malignancies, and serious infections.

OBJECTIVES

We assessed cardiovascular, malignancy, and serious infection risks associated with JAKi use compared to tumor necrosis factor inhibitor (TNFi) use, which served as the active comparator, in patients with rheumatoid arthritis (RA) or ulcerative colitis (UC).

METHODS

This study emulated a target trial using South Korea's nationwide claims database (2013-2023). We constructed two separate cohorts comprising new users of JAKi or TNFi with either RA or UC and performed overlap weighting to control for confounders. Outcomes included three-point-major adverse cardiovascular events (3P-MACE) (cardiovascular death, myocardial infarction, and stroke), malignancy, and serious infection. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

The RA cohort included 14,972 patients, with 4759 initiating JAKi. The UC cohort included 2085 patients, with 347 initiating JAKi. In the overall RA cohort, the weighted HR was 0.92 (95% CI 0.59-1.42) for 3P-MACE, 1.61 (1.08-2.41) for malignancy, and 1.08 (0.94-1.23) for serious infection. In the overall UC cohort, the weighted HR was 0.98 (0.11-8.42) and 0.45 (0.26-0.78) for malignancy and serious infection, respectively. No 3P-MACE cases were observed in JAKi users.

CONCLUSIONS

JAKis were associated with an elevated risk of malignancy but no significant difference in the risk of 3P-MACE and serious infection among all patients with RA. Further data are needed regarding the risk of malignancy and 3P-MACE in patients with UC.

JAK2 inactivating mutations promotes endometrial cancer progression by targeting HIF-1α

OBJECTIVE

Endometrial cancer (EC) is the ninth most common malignancy among women. While mutations in JAK2 are frequently observed in EC, the specific biological functions of JAK2 in endometrial cancer are poorly understood.

METHODS

The genetic alterations of JAK2 in different cancer types were explored using sequencing dataset deposited at TCGA database. JAK2 mutations were detected in EC formalin-fixed paraffin-embedded (FFPE) samples using Sanger sequencing. The expression levels of JAK2 was accessed using the TCGA database and immunohistochemistry. Furthermore, the relationships between JAK2 expression and staging and prognosis of EC patients were investigated using the TCGA database. Down-regulation of JAK2 were achieved by transient transfection with short hairpin RNAs (shRNAs). Effects of JAK2 on cancer cells proliferation and migration were evaluated by CCK8, colony formation, and transwell assay. The potential biological functions of JAK2 in EC were identified based on bioinformatics analysis. Effects of JAK2 on expression levels of target genes were detected by RT-qPCR and western blotting. Co-immunoprecipitation (co-IP) assays was used to detect the physical association between JAK2 and HIF-1α.

RESULTS

Frequent mutations and down-regulation of JAK2 were found in EC. Loss-of-function (LOF) assays suggested that JAK2 silencing in endometrial cancer cells promoted cell proliferation and migration, which were partially dependent on HIF-1α signaling pathway. Furthermore, our findings demonstrated that JAK2 interacted with HIF-1α and reduced HIF1α protein expression under hypoxia.

CONCLUSION

These findings revealed novel molecular mechanisms underlying JAK2 LOF mutations-driven endometrial tumorigenesis and revealed that the HIF-1α pathway may be a potential therapeutic target in JAK2-mutated endometrial cancer.

Hypoxia and the endometrium: An indispensable role for HIF-1α as therapeutic strategies

Hypoxia-inducible factor 1 alpha (HIF-1α) is a major molecular mediator of the hypoxic response. In the endometrium, local hypoxic conditions induced by hormonal fluctuations and endometrial vascular remodeling contribute to the production of HIF-1α, which plays an indispensable role in a series of physiological activities, such as menstruation and metamorphosis. The sensitive regulation of HIF-1α maintains the cellular viability and regenerative capacity of the endometrium against cellular stresses induced by hypoxia and excess reactive oxygen species. In contrast, abnormal HIF-1α levels exacerbate the development of various endometrial pathologies. This knowledge opens important possibilities for the development of promising HIF-1α-centered strategies to ameliorate endometrial disease. Nonetheless, additional efforts are required to elucidate the regulatory network of endometrial HIF-1α and promote the applications of HIF-1α-centered strategies in the human endometrium. Here, we summarize the role of the HIF-1α-mediated pathway in endometrial physiology and pathology, highlight the latest HIF-1α-centered strategies for treating endometrial diseases, and improve endometrial receptivity.

CD74-ROS1 L2026M mutant enhances autophagy through the MEK/ERK pathway to promote invasion, metastasis and crizotinib resistance in non-small cell lung cancer cells

The treatment of non-small cell lung cancer (NSCLC) patients harboring a proto-oncogene tyrosine-protein kinase c-ros oncogene 1 (ROS1) fusion gene has greatly benefited from the use of crizotinib. However, drug resistance inevitably occurs after 1 year of treatment. Clinical studies have shown that patients with an L2026M mutation in the ROS1 kinase domain account for about 6% of the total number of crizotinib-resistant cases, which is an important group that cannot be ignored. To explore the mechanism involved, we constructed the HLA class II histocompatibility antigen gamma chain (CD74)-ROS1 L2026M mutant gene by fusion polymerase chain reaction (PCR) and transfected it into H460 and A549 cells. We found that the invasion and metastasis abilities of drug-resistant cells were increased. The results of monodansylcadaverine (MDC) staining, Acridine orange (AO) staining, and western blot indicated that the autophagy level of CD74-ROS1 L2026M mutant NSCLC cells was increased compared with the CD74-ROS1 group, and the inhibition of autophagy could reverse the increased invasion and metastasis abilities caused by the L2026M mutation. In addition, the L2026M mutation led to excessive activation of the MEK/ERK pathway, and MEK inhibitors could reduce the autophagy level, invasion, and metastasis abilities of cells; additionally, this process could be blocked by rapamycin, an activator of autophagy. Furthermore, crizotinib treatment activated expression of Src homology region 2 domain-containing phosphatase-2 (SHP2; also known as PTPN11) to upregulate the MEK/ERK pathway, and the combination of MEK inhibitors and crizotinib increased apoptosis compared with crizotinib alone. In conclusion, our results indicate that the MEK/ERK pathway mediates the induction of invasion, metastasis, and crizotinib resistance through autophagy caused by CD74-ROS1 L2026M mutation in NSCLC cells, and targeting MEK could reverse these processes.