HECTD2/TNFAIP1 Axis Regulating the p38/JNK Pathway to Promote an Inflammatory Response in Renal Cell Carcinoma Cells

BACKGROUND/AIM

The underlying processes of renal cell carcinoma (RCC), one of the deadliest malignancies of the urinary system, are still poorly understood. HECT domain E3 ubiquitin protein ligase 2 (HECTD2) is an E3 ubiquitin ligase implicated in the pulmonary inflammatory response. This study investigated the impact of HECTD2 on regulating inflammation in RCC cells and its potential mechanisms.

MATERIALS AND METHODS

HECTD2 expression in RCC tissues was examined. Immunoprecipitation and western blot (WB) analysis confirmed that HECTD2 up-regulated euchromatic histone lysine methyltransferase 2 (EHMT2) protein degradation. ChIP experiments validated tumor necrosis factor α Inducing protein 1 (TNFAIP1) as a direct target of EHMT2. qRT-PCR determined HECTD2 and TNFAIP1 expression in RCC cells. Cell viability was assayed via CCK-8. ELISA was employed to measure the expression of IL-6, TNF-α, IL-8, and IL-1β. WB analysis was conducted to test p38/JNK pathway-related protein (p38, p-p38, JNK, and p-JNK) expression.

RESULTS

HECTD2 and TNFAIP1 were significantly up-regulated in RCC patient tissues and cells. Subsequent investigations revealed that HECTD2 promoted an inflammatory response in RCC cells. Additionally, HECTD2 up-regulated TNFAIP1 expression, and high TNFAIP1 expression could reverse the repressive impact of low HECTD2 expression on the inflammatory response in RCC cells. Rescue experiments demonstrated that the addition of p38/JNK pathway inhibitors attenuated the impact of TNFAIP1 overexpression on the RCC inflammatory response.

CONCLUSION

Our findings establish a new mechanism by which HECTD2 exerts a pro-inflammatory role in RCC cells and present a prospective method for an anti-inflammatory intervention targeting the HECTD2/TNFAIP1 axis in malignancies.

A genome-wide association scan reveals novel loci for facial traits of Koreans

DNA-based prediction of externally visible characteristics (EVC) with SNPs is one of the research areas of interest in the forensic field. Based on a previous study performing GWAS on facial traits in a Korean population, herein, we present results stemming from GWA analysis with KoreanChip and novel genetic loci satisfying genome-wide significant level. We discovered a total of 20 signals and 12 loci were found to have novel associations with facial traits, including six loci located in intergenic regions and six loci located at UBE2O, HECTD2, CCDC108, TPK1, FCN2, and FRMPD1. Additionally, we performed a polygenic score analysis for 33 distance-related traits in facial phenotyping and determined genetic relationships between facial traits and SNPs using the GCTA program. The results of the current study offer an understanding of how facial morphology is influenced by complex genetic structures and provide insights into forensic investigation and population genetics.

[HECTD2 Represses Cell Proliferation in Colorectal Cancer through Driving Ubiquitination and Degradation of LPCAT1]

Colorectal cancer (CRC) is a malignancy featured by a poor overall survival and a high recurrence rate, whereas the biomarkers for CRC remain to be investigated. Herein, it was found that lysophosphatidylcholine acyltransferase 1 (LPCAT1) was highly expressed in CRC, and LPCAT1 overexpression significantly promoted CRC cell proliferation, while it was reversed by LPCAT1 depletion. In addition, HECT domain-containing 2 (HECTD2) protein was determined as a post-translational mediator of LPCAT1 because HECTD2 co-immunoprecipitated with high ubiquitinated LPCAT1. Furthermore, upregulated LPCAT1 rescued the impairment of CRC cell proliferation caused by HECTD2 overexpression. In conclusion, our findings supported HECTD2/LPCAT1 axis as a potential prognostic biomarker in CRC.

HIF-1α Induces HECTD2 Up-Regulation and Aggravates the Malignant Progression of Renal Cell Cancer via Repressing miR-320a

Renal cell carcinoma (RCC) is a frequent malignancy of the urinary system. It has been found that hypoxia mediates the malignant evolvement of RCC. Here, we probe the impact and potential mechanism of HECT domain E3 ubiquitin-protein ligase 2 (HECTD2) and HIF-1α on regulating RCC evolvement. RCC tissues and adjacent normal tissues were collected, and the association between the expression profiles of HECTD2 and HIF-1α and the clinicopathological features was analyzed. Additionally, we constructed HECTD2/HIF-1α overexpression and knockdown models in RCC cell lines to ascertain the impacts of HECTD2 and HIF-1α on RCC cell proliferation, apoptosis, migration, and growth in vivo. We applied bioinformatics to predict the upstream miRNA targets of HECTD2. Meanwhile, RNA immunoprecipitation (RIP), and the dual-luciferase reporter assays were employed to clarify the targeting association between HECTD2 and miR-320a. The effect of miR-320a on HECTD2-mediated RCC progression was investigated. The results suggested that both HIF-1α and HECTD2 were up-regulated in RCC (compared with adjacent non-tumor tissues), and they had positive relationship. Moreover, higher level of HECTD2 and HIF-1α is associated with poorer overall survival of RCC patients. HECTD2 overexpression heightened RCC cell proliferation and migration, and weakened cell apoptosis. On the other hand, the malignant phenotypes of RCC cells were signally impeded by HECTD2 or HIF-1α knockdown. Moreover, miR-320a targeted the 3'-untranslated region of HECTD2 and suppressed HECTD2 expression. The rescue experiments showed that miR-320a restrained HECTD2-mediated malignant progression in RCC, while up-regulation of HIF-1α hampered miR-320a expression. Collectively, HIF-1α mediated HECTD2 up-regulation and aggravated RCC progression by attenuating miR-320a.