LIMCH1 suppress the growth of lung cancer by interacting with HUWE1 to sustain p53 stability

Background: The aim of this study was to identify the expression of LIM and calponin-homology domains 1 (LIMCH1) in lung cancer and normal tissues, to determine the interaction between LIMCH1 and HUWE1 in regulating p53 stability. Methods: The expression of LIMCH1 was detected by the Oncomine and Cancer Genome Atlas databases. Expression of LIMCH1 mRNA was identified using qRT-PCR. In transfected human lung cancer cells, co-immunoprecipitation experiments were performed. The mechanism that HUWE1 sustained lung cancer malignancy was verified by western blotting. The proliferation of tranfected cells was assessed by CCK-8 assay and colony formation. Results: Bioinformatic data and e TCGA database suggested LIMCH1 mRNA levels in tumor tissues were down regulated compared to tumor adjacent tissues. We found low expression of LIMCH1 mRNA in tumor sites and tumor cell line. Exogenous expression of LIMCH1 interacts with HUWE1 promotes expression of p53. Use of siRNA or shRNA against LIMCH1 resulted in decreased p53 protein levels. LIMCH1 deletion lead to enhance of p53 ubiquitination and protein expression of p53 and substrate p21, puma. Growth curve showed that LIMCH1 deletion significantly promoted the proliferation of A549 cells. Conclusions: LIMCH1 was a negative regulator and indicated a new molecular mechanism for the pathogenesis of lung cancer via modulating HUWE1 and p53.