Cathelicidin hCAP18/LL-37 promotes cell proliferation and suppresses antitumor activity of 1,25(OH) 2 D 3 in hepatocellular carcinoma
Huidan Zhang 1 , Junai Zhen 1 , Rong Zhang 1 , Yangke Wanyan 1 , Kehang Liu 1 , Xueli Yuan 1 , Liping Tao 1 , Yuqing Chen 2 Affiliations
- PMID: 35039485
- PMCID: PMC8763942
- DOI: 10.1038/s41420-022-00816-w
Free PMC article
Cathelicidin hCAP18/LL-37 can resist infection from various pathogens and is an essential component of the human immune system. Accumulating evidence has indicated that hCAP18/LL-37 plays a tissue-specific role in human cancer. However, its function in hepatocellular carcinoma (HCC) is poorly understood. The present study investigated the effects of hCAP18/LL-37 on HCC in vitro and in vivo. Results showed that hCAP18/LL-37 overexpression significantly promoted the proliferation of cultured HCC cells and the growth of PLC/PRF-5 xenograft tumor. Transcriptome sequencing analyses revealed that the PI3K/Akt pathway was the most significant upregulated pathway induced by LL-37 overexpression. Further analysis demonstrated that hCAP18/LL-37 stimulated the phosphorylation of EGFR/HER2 and activated the PI3K/Akt pathway in HCC cells. Furthermore, stronger EGFR/HER2/Akt signals were observed in the PLC/PRF-5LL-37 xenograft tumor. Interestingly, even though the expression of hCAP18/LL-37 was significantly downregulated in HCC cells and tumors, 1,25(OH)2D3 treatment significantly upregulated the hCAP18/LL-37 level both in HCC cells and xenograft tumors. Moreover, 1,25(OH)2D3 together with si-LL-37 significantly enhanced the antitumor activity of 1,25(OH)2D3 in the PLC/PRF-5 xenograft tumor. Collectively, these data suggest that hCAP18/LL-37 promotes HCC cells proliferation through stimulation of the EGFR/HER2/Akt signals and appears to suppress the antitumor activity of 1,25(OH)2D3 in HCC xenograft tumor. This implies that hCAP18/LL-37 may be an important target when aiming to improve the antitumor activity of 1,25(OH)2D3 supplementation therapy in HCC.