CEMIP promotes small cell lung cancer proliferation by activation of glutamine metabolism via FBXW7/c-Myc-dependent axis.

Small cell lung cancer (SCLC) is the most malignant lung cancer with rapid growth and early metastasis, but still lacks effective targeted therapies to improve the prognosis. Here, we demonstrated that a novel oncogenic protein, cell migration inducing hyaluronic binding protein (CEMIP), was robustly overexpressed in SCLC tissues than that in noncancerous tissues and high expression of CEMIP predicted poor outcomes in clinical specimens and in large sample size cohorts from public databases (GEPIA 2 and CPTAC). Liquid chromatography mass spectrometry (LC-MS) and in vitro/in vivo functional assays indicated that CEMIP contributed to the proliferation by increasing glutamine consumption and their metabolites (glutamate and glutathione) levels in SCLC cells. Moreover, the addition of a GLS1 inhibitor CB-839 dramatically reduced CEMIP-induced SCLC cell proliferation. Mechanistically, beyond as a scaffold protein, CEMIP facilitates glutamine-dependent cell proliferation through inhibiting c-Myc ubiquitination and increasing c-Myc stabilization and nuclear accumulation via hindering the interaction between FBXW7 (a E3 ubiquitin ligase) and its target substrate c-Myc. Taken together, our findings reveal a novel oncogenic role of CEMIP in sustaining SCLC growth via FBXW7/c-Myc-dependent axis, and provide new evidence that inhibition of CEMIP might be a potential therapeutic strategy for the treatment of SCLC.

KIAA1199 Correlates With Tumor Microenvironment and Immune Infiltration in Lung Adenocarcinoma as a Potential Prognostic Biomarker.

Background: KIAA1199 has been considered a key regulator of carcinogenesis. However, the relationship between KIAA1199 and immune infiltrates, as well as its prognostic value in lung adenocarcinoma (LUAD) remains unclear. Methods: The expression of KIAA1199 and its influence on tumor prognosis were analyzed using a series of databases, comprising TIMER, GEPIA, UALCAN, LCE, Prognoscan and Kaplan-Meier Plotter. Further, immunohistochemistry (IHC), western blot (WB) and receiver operating characteristic (ROC) curve analyses were performed to verify our findings. The cBioPortal was used to investigate the genomic alterations of KIAA1199. Prediction of candidate microRNA (miRNAs) and transcription factor (TF) targeting KIAA1199, as well as GO and KEGG analyses, were performed based on LinkedOmics. TIMER and TISIDB databases were used to explore the relationship between KIAA1199 and tumor immune infiltration. Results: High expression of KIAA1199 was identified in LUAD and Lung squamous cell carcinoma (LUSC) patients. High expression of KIAA1199 indicated a worse prognosis in LUAD patients. The results of IHC and WB analyses showed that the expression level of KIAA1199 in tumor tissues was higher than that in adjacent tissues. GO and KEGG analyses indicated KIAA1199 was mainly involved in extracellular matrix (ECM)-receptor interaction and extracellular matrix structure constituent. KIAA1199 was positively correlated with infiltrating levels of CD4+ T cells, macrophages, neutrophil cells, dendritic cells, and showed positive relationship with immune marker subsets expression of a variety of immunosuppressive cells. Conclusion: High expression of KIAA1199 predicts a poor prognosis of LUAD patients. KIAA1199 might exert its carcinogenic role in the tumor microenvironment via participating in the extracellular matrix formation and regulating the infiltration of immune cells in LUAD. The results indicate that KIAA1199 might be a novel biomarker for evaluating prognosis and immune cell infiltration in LUAD.

Nitidine chloride induces caspase 3/GSDME-dependent pyroptosis by inhibting PI3K/Akt pathway in lung cancer.

BACKGROUND: As the increasing mortality and incidence of lung cancer (LC), there is an urgent need to discover novel treatment agent. In this study, we aimed to investigate the anti-LC effects of nitidine chloride (NC), a small molecular compound extracted from Chinese herbal medicine, while detailing its underlying mechanisms. METHODS: Cell viability was detected by MTT assays and five cell death inhibitors, including ferrostatin-1 (Fer-1), Z-VAD-FMK, necrostatin-1 (Nec-1), disulfiram (DSF) and IM-54 were used to explore the type of cell death induced by NC. The microscopic features of NC-induced pyroptosis were assessed by transmission electron microscopy (TEM) and the pyroptotic-related proteins such as caspase and gasdermin family, were examined by western blot. Network pharmacology was employed to predict the potential mechanisms of NC in lung cancer treatment. CETSA and DARTs were used to determine the activity of NC binding to targeted protein. Xenograft mice model was established to further investigate the inhibitory effect and mechanism of NC against LC. RESULTS: The pyroptosis inhibitor (DSF) and apoptosis inhibitor (Z-VAD-FMK) but not IM-54, necrostatin-1, or Ferrostatin-1 rescued NC-induced cell death. Morphologically, H1688 and A549 cells treated with NC showed notably pyroptotic features, such as cell swelling and large bubbles emerging from the plasma membrane. Gasdermin E (GSDME) rather than GSDMC or GSDMD was cleaved in NC-treated H1688 and A549 cells with an increased cleavage of caspase 3. Combined with network pharmacology and molecule docking, PI3K/Akt signaling axis was predicted and was further verified by CETSA and DARTs assay. In addition, the activation of PI3K is able to rescue the pyroptosis induced by NC in vitro. In xenograft model of LC, NC significantly hindered the transduction of PI3K-AKT pathway, inducing pyroptosis of tumor. CONCLUSION: Our data indicated that NC is a potential therapeutic agent for the treatment of LC via triggering GSDME-dependent pyroptosis.