Cervical cancer poses a significant threat to women’s health, and its metastasis is one of the leading causes of cancer-related deaths. Tubeimoside I (TBMS1) is a traditional Chinese medicinal herb with anticancer properties. We previously demonstrated the anticancer effect of TBMS1 in cervical cancer by inducing autophagy-related cell death. Nevertheless, whether and how TBMS1 prevents cervical cancer metastasis remain unclear. Wound healing, transwell assays, and a lung metastasis mouse model were used to evaluate cell metastasis. Immunoprecipitation combined with site-directed mutagenesis was used to explore ubiquitination modifications and ubiquitinated sites of histone deacetylase 5 (HDAC5). HDAC5 depletion and RNA-seq analysis were conducted to investigate the anti-metastatic mechanism of TBMS1. We show that low dose of TBMS1 inhibits cervical cancer metastasis. Mechanistically, TBMS1 binds to HDAC5 and prevents HDAC5 ubiquitination at lysine 137 and 538, leading to a decrease in proteasomal degradation of HDAC5. TBMS1-mediated HDAC5 upregulation further reduces the acetylation level of histone H3 lysine 27 (H3K27ac) and suppresses KPNA2 expression. HDAC5 depletion significantly attenuates TBMS1’s anti-metastatic effect in cervical cancer. Our study reveals HDAC5/H3K27ac/KPNA2 axis as the anti-metastatic mechanism of TBMS1 in cervical cancer, suggesting TBMS1 serves as a promising drug for cervical cancer treatment.

ErbB2 is overexpressed in 15-20% of breast cancer, which is associated with malignancy and poor prognosis. We previously reported that ErbB2 supports malignant progression of breast cancer by upregulating lactate dehydrogenase A (LDHA), an important enzyme in glycolysis. However, whether ErbB2 promotes breast cancer progression through other glycolytic enzymes remains unclear. Hexokinase 1 (HK1) and hexokinase 2 (HK2) are the first rate-limiting enzymes of glycolysis and both of them are increased in breast cancer. Here, we aim to investigate whether ErbB2 upregulates HK1 and HK2 and the role of HK1 and HK2 in the malignant progression of ErbB2-overexpressing breast cancer. In current study, we found that the mRNA level of ErbB2 was positively correlated with that of HK1 and HK2, respectively. Moreover, ErbB2 upregulated the protein levels of HK1 and HK2 in breast cancer cells. We also found that both siHK1 and siHK2 significantly inhibited the proliferation, migration and invasion of ErbB2-overexpressing breast cancer cells. Taken together, our findings suggested that ErbB2 promoted the malignant progression of breast cancer cells by upregulating HK1 and HK2, and HK1 and HK2 might serve as promising therapeutic targets for ErbB2-overexpressing breast cancer.

ErbB2 is overexpressed in approximately 25% of breast cancer cases and promotes metastatic potential. We previously reported that ErbB2 promoted glycolysis via heat shock factor 1 (HSF1)/lactate dehydrogenase A (LDHA) axis and ErbB2-mediated glycolysis was required for the growth of breast cancer cells. However, the importance of HSF1/LDHA axis-mediated glycolysis in ErbB2-enhanced metastatic potential remains to be elucidated. In this study, we investigated the effect of HSF1/LDHA axis-mediated glycolysis on migration and invasion in breast cancer cells. Firstly, we demonstrated that ErbB2-mediated migration and invasion were dependent on glycolysis in breast cancer cells. Secondly, we found that HSF1/LDHA axis played an important role in glycolysis, which contributed to ErbB2-enhanced migration and invasion. Finally, we showed that ErbB2 was positively correlated with HSF1/LDHA axis in invasive breast cancer patients via GEO analysis. Taken together, ErbB2 promoted metastatic potential of breast cancer cells via HSF1/LDHA axis-mediated glycolysis. And our findings indicated that targeting HSF1/LDHA axis may be a promising strategy to treat ErbB2-overexpressing breast cancer patients.

The incidence of breast cancer ranks at the top of female malignant tumors in China. Metastasis remains the main cause of death among breast cancer patients. The overexpression of ErbB2 is closely related to the metastasis and poor prognosis of breast cancer patients. Therefore, ErbB2 is an important clinical therapeutic target of breast cancer. However, the molecular mechanism of ErbB2 promoting breast cancer metastasis has not been studied clearly. Stearoyl-CoA desaturase 1 (SCD1) is a key enzyme in catalyzing the conversion of saturated fatty acids (SFAs) into monounsaturated fatty acids (MUFAs). SCD1 is overexpressed in breast cancer, and its overexpression is an indicator of poor prognosis in breast cancer patients. However, the role of SCD1 in ErbB2-overexpressing breast cancer metastasis has not been reported. In this study, we investigated the role of SCD1 in the migration and invasion of ErbB2-overexpressing breast cancer cells and its molecular mechanism. First, we demonstrated that ErbB2 upregulates the expression of SCD1. Second, we found that SCD1 and its catalytic product oleic acid played crucial roles in migration and invasion of ErbB2-overexpressing breast cancer cells. Finally, we found that in breast cancer cells, ErbB2 upregulated SCD1 through lactate dehydrogenase A (LDHA). To sum up, upregulation of SCD1 by ErbB2 via LDHA promotes the migration and invasion of breast cancer cells.

目的 在体外研究小干扰RNA(siRNA)沉默己糖激酶2(HK2)对人乳腺癌SK-BR-3细胞增殖、迁移和侵袭的影响及其分子机制.方法 在SK-BR-3细胞中分别转染siRNA阴性、siHK2-A和siHK2-B,分别采用荧光定量PCR和Western Blot法检测HK2 mRNA和蛋白的表达水平;MTT法检测细胞的增殖;Transwell小室检测细胞的迁移和侵袭;葡萄糖检测试剂盒检测细胞对葡萄糖的摄取.结果 与阴性对照组比较,siHK2能显著降低SK-BR-3细胞的HK2 mRNA及蛋白水平,抑制细胞增殖、迁移和侵袭能力,减少细胞对葡萄糖的摄取.结论 siHK2可能通过降低葡萄糖摄取来抑制SK-BR-3细胞的增殖、迁移和侵袭.

Objective To investigate the heregulin-β1 (HRG-β1)-induced expression of stearoyl-CoA desaturase-1 (SCD1) and the effect of its activity of SCD1 on the proliferation, migration and invasion of breast cancer cells MCF7 and SK-BR-3. Methods MCF7 and SK-BR-3 cells were treated with control (PBS) or HRG-β1 at different concentrations and for different times. Then RT-qPCR and Western blotting were used to detect the mRNA and protein expression levels of SCD1. The wound healing assay and Transwell assay were employed to measure the migration and invasion of MCF7 and SK-BR-3 cells treated with PBS, HRG-β1, A939572 and oleic acid (OA). Results HRG-β1 increased both SCD1 mRNA and protein levels in MCF7 and SK-BR-3 cells at a time-dose dependent manner. Compared with the control group, HRG-β1 promoted cell proliferation in MCF7 and SK-BR-3 cells (P < 0.01), while proliferation rate was decreased after A939572 treatment (P < 0.01). Compared with the control group, HRG-β1 significantly increased the wound healing rates and invaded cell numbers of MCF7 and SK-BR-3 cells (P < 0.01). The wound healing rates and invaded cell numbers of both cell lines were significantly decreased after HRG-β1+A939572 treatment (P < 0.01). The addition of OA rescued the migration and invasion of both cell lines which were weakened by A939572 (P < 0.01). Conclusions HRG-β1 can up-regulate the expression of SCD1, and the protein partially mediates the effect of HRG-β1 in promoting the proliferation, migration and invasion in MCF7 and SK-BR-3 cells.

OBJECTIVE:To investigate the effect of small interfering RNA of lactate dehydrogenase A (siLDHA) on migration and invasion of epidermal growth factor receptor 2 (ErbB2) over expressing breast cancer cell line SK-BR-3, MDA-MB-453 and its molecular mechanism.METHODS:SK-BR-3 and MDA-MB-453 cells were transfected with siLDHA to interfere with the expression of LDHA. The transfection of scramble siRNA was used as negative control. The LDHA protein levels were detected by Western blot ( P<0.01). Cell migration and invasion was detected by Transwell assays. Lactate dehydrogenase (LDH) activity was measured by LDH assay kit. The glucose and lactate concentration in the culture media was determined by glucose and lactate assay kit, respectively, and then glucose uptake and lactate production by the cells were calculated.RESULTS:siLDHA downregulated LDHA protein levels in SK-BR-3 and MDA-MB-453 cells ( P<0.01). Compared with negative control group, siLDHA significantly decreased migration and invasion of SK-BR-3 and MDA-MB-453 cells ( P<0.001). siLDHA reduced LDH activity in SK-BR-3 cells, glucose uptake and lactate production in SK-BR-3 and MDA-MB-453 cells, the difference was significant ( P<0.05).CONCLUSION:Knockdown of LDHA by siRNA inhibits the migration and invasion via downregulation of glycolysis in ErbB2 over expressing breast cancer cell line.