Together, all our results indicate that HRH3 facilitates cell growth through inactivating the cAMP/PKA/CREB signaling pathway in HCC
February 14, 2022
Together, all our results indicate that HRH3 facilitates cell growth through inactivating the cAMP/PKA/CREB signaling pathway in HCC. Previous studies revealed a cluster of PKA, protein kinase C (PKC), and casein kinase II consensus recognition sites near the N terminus of CREB, which indicated the possibility of interaction in a positive or unfavorable fashion to regulate CREB bioactivity.27 Transcription was stimulated on binding to the cAMP response element of a phosphorylated CREB dimer. effect of HRH3 on tumor growth in vivo. Results Our results indicated that HRH3 was significantly upregulated in HCC, which promoted cell survival by accelerating cell proliferation and inhibiting cell apoptosis. Our results also showed that HRH3 in HCC downregulated the expression of cyclin-dependent kinase inhibitor p21 (CDKN1A) to promote G1-S phase transition by Fendiline hydrochloride inactivating the cAMP/PKA/CREB pathway, which finally contributed to the malignant growth of HCC. Conclusion Our findings indicated that HRH3 functioned in promoting HCC survival by inactivating the cAMP/PKA/CREB pathway to downregulate CDKN1A expression. Thus, HRH3 might serve as a potential therapeutic target in HCC treatment. for 10 min. Then, the supernatant extract was further analyzed for cAMP level according to the manufacturers protocol. Read the plate at 450 nm using a microplate reader (Bio-Rad). The cAMP concentration was quantified according to the standard curve. The PKA activity was detected using the PKA kinase activity kit. Briefly, cells were lysed with lysis buffer for 10 min on ice, followed by collecting and centrifuging at 21?000 for 15 min. Then, the supernatant extract was further analyzed for PKA kinase activity according to the manufacturers protocol. Finally, the microplate was read at 450 nm using a microplate reader (Bio-Rad). Nude Mice Xenograft Model All animal procedures were approved by the Institutional Animal Care and Use Committee of West China Hospital of Sichuan University. Experimental procedures were performed in accordance with the Guideline for the Care and Use of Laboratory Animals (National Institutes of Health Publications) and according to the institutional ethical guidelines for animal experiments. Fifteen male BALB/c mice (5 weeks aged; body weight, 18C22 g) were randomly divided into five groups. Xenografts were initiated by subcutaneous injection of HCC cells into the back of mice on the right side (n = 3 per group). One week later, 1.5 mg/kg cholesterol-conjugated siCDKN1A was EIF2B4 administered thrice per week for four weeks by intratumoral injection. The mice in other groups were similarly injected with the same volume of dimethyl sulfoxide (DMSO). The mice were euthanized by injection of an overdose of pentobarbital sodium, and tumor nodules were photographed and weights calculated. A tumor growth curve was plotted according to the data of tumor volume. The tumor volume (mm3) was calculated by the formula (length width2)/2. Statistical Analysis Independent experiments were performed thrice where appropriate. SPSS 17.0 (SPSS, Chicago, IL) was used for all statistical analyses and 0.05 was considered statistically significant. The unpaired 0.01, 0.01, respectively) (Figure 1A and ?andB).B). Similarly, IHC staining results also showed that HRH3 protein expression was remarkably increased in HCC tissues when compared with that in the peritumor tissues ( 0.01) (Physique 1C). Moreover, we analyzed the relationship between the HRH3 expression level and the pathological characteristic of patients with HCC (Table S3) and found that HRH3 expression level in patients with low differentiation HCC was remarkably higher than that in patients with high and medium differentiation HCC (= 0.008). KaplanCMeier survival analysis revealed that HCC patients with high HRH3 expression had significantly shorter overall survival when compared with those in HCC patients with low HRH3 expression (Physique 1D). Taken together, these data indicate that HRH3 is usually upregulated in HCC, which contributes to the progression and poor prognosis of HCC. Open in a separate windows Physique 1 HRH3 was upregulated and associated with clinical prognosis in HCC. (A) qRT-PCR and (B) Western blot analyses of the relative mRNA and protein expression level of HRH3 in 15 paired tumor and peritumor tissues, respectively. -actin was used as the internal control. (C) Representative immunohistochemistry IHCstaining images of HRH3 in paired HCC tissues (n = 86). (D) KaplanCMeier curve analysis of overall survival (OS) in patients with HCC by the expression of HRH3 in HCC tissues. Total number of patients in each subgroup is usually presented. Data are presented as mean SEM from three impartial experiments. HRH3 Promotes HCC Cell Growth in vitro To assess the potential effects of HRH3 on cell growth, a series of biological experiments were performed with gain-of-function or loss-of-function of HRH3. We used siRNA to silence HRH3 expression in HepG2 and PLC/PRF/5 cells, and verified Fendiline hydrochloride the silencing efficiency by qRT-PCR (Supplementary Physique 1A) and Western blot (Physique 2A). MTS assay showed that HRH3 knockdown in HepG2 and PLC/PRF/5 cells significantly reduced cell growth in comparison with the control Fendiline hydrochloride (Physique 2B). As supported, EdU incorporation assay also exhibited that knockdown of HRH3 in HepG2 and PLC/PRF/5 cells significantly attenuated cell proliferation activity compared to the control (Physique 2C). Moreover, we also tested the effect of HRH3 knockdown around the apoptosis of HCC cells. As shown in Physique 2D and supplementary Physique 1B, knockdown of HRH3 in HepG2 and PLC/PRF/5.