Phase II study of apatinib plus exemestane in estrogen receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer.

PURPOSE: Apatinib is a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor (VEGFR)-2. This study was conducted to assess the efficacy and safety of apatinib combined with exemestane in patients with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). METHODS: This single-center, single-arm phase II study enrolled patients with ER+/HER2- MBC progressed on previous letrozole or anastrozole. Stratified analysis was performed according to the number of chemotherapy regimens for metastatic disease. The primary endpoint was progression free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), overall survival (OS) and toxicity. Patients received apatinib at a starting dose of 500 mg/d and exemestane 25 mg/d on days 1-28 of each 4-week cycle. RESULTS: Thirty patients were enrolled with median four prior anticancer therapies. Eighty percent of patients received chemotherapy for metastatic disease. The median PFS (mPFS) and OS were 5.6 (95%CI: 4.3-6.9) months and 15.7 (95% CI: 9.7-21.7) months, respectively. The ORR, DCR, and CBR were 21.4%, 71.4%, and 46.4%, respectively. Patients with 0-1 line chemotherapy for MBC showed a slightly longer mPFS compared to those with ≥2 lines chemotherapy (mPFS: 6.4 months vs 4.8 months, P = .090). Most of the AEs were grade 1/2. One patient (3.3%) who suffered bone marrow metastases experienced grade 4 thrombocytopenia, and 14 experienced grade 3 AEs. Fifty percent of patients were given reduced dose for apatinib. CONCLUSIONS: Apatinib plus exemestane exhibited objective efficacy in patients with ER+/HER2- MBC who have failed multiple lines of treatment. The AEs of apatinib required close monitoring and most of patients were well tolerated.

Efficacy and safety of continuous infusion of Rh-endostatin combined with platinum-based chemotherapy for advanced triple-negative breast cancer.

BACKGROUND: This study aimed to prospectively evaluate and investigate the efficacy and safety of recombinant human endostatin (Rh-endostatin) combined with platinum-based regimens for advanced triple-negative breast cancer (TNBC) patients. METHODS: This study was a prospective, single-arm, single-center, open-label trial. From January 2017 to August 2019, 21 women aged 18-70 years with histologically confirmed advanced TNBC were enrolled. Rh-endostatin at 30 mg/d was continuously pumped for 7 days and used synchronously with the chemotherapy cycle. The primary endpoint of this study was progression-free survival (PFS). Secondary endpoints included objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), overall survival (OS), and toxicity. RESULTS: The median PFS (mPFS) was 8.8 months (95% CI: 7.2-10.4 months), and the median OS was 13.3 months (95% CI: 11.6-15.0 months). The ORR and CBR for the whole population were 47.6% and 52.4%, respectively. Patients sensitive to anthracycline and taxane drugs showed a significantly longer mPFS compared to those who were resistant to anthracycline and taxane drugs (mPFS: 8.8 vs. 5.3 months, P=0.038). For patients who received first- and second-line therapy or beyond, the mPFS was 8.8 and 5.3 months, respectively, with a significant difference (P=0.025). No statistically significant differences in the mPFS between pemetrexed combined with platinum and gemcitabine/taxanes combined with platinum were observed. The most common grade 3-4 hematologic toxicities were neutropenia (14.3%) and anemia (14.3%). One patient (4.8%) experienced febrile neutropenia. No grade 3-4 non-hematologic toxicities were observed, and no treatment-related deaths were reported in this study. CONCLUSIONS: This study revealed that Rh-endostatin might enhance the antitumor effects of platinum-based chemotherapy for advanced TNBC patients with well-tolerated toxicities, which may provide a new basis and novel idea for the treatment of TNBC. However, further investigations and validation of its long-term efficacy and toxicity are warranted in the future.

Mesenchymal Stem Cell-Secreted Exosome Promotes Chemoresistance in Breast Cancer via Enhancing miR-21-5p-Mediated S100A6 Expression.

Emerging evidence has shown the role of mesenchymal stem cell-derived exosome (MSC-exo) in inducing resistance of cancer cells to chemotherapy. However, it remains unclear whether the change of MSC-exo in response to chemotherapy also contributes to chemoresistance. In this study, we investigated the effect of a standard-of-care chemotherapeutic agent, doxorubicin (Dox), on MSC-exo and its contribution to the development of Dox resistance in breast cancer cells (BCs). We found that the exosome secreted by Dox-treated MSCs (Dt-MSC-exo) induced a higher degree of Dox resistance in BCs when compared with non-treated MSC-exo. By analysis of the MSC-exo-induced transcriptome change in BCs, we identified S100A6, a chemoresistant gene, as a top-ranked gene induced by MSC-exo in BCs, which was further enhanced by Dt-MSC-exo. Furthermore, we found that Dox induced the expression of miR-21-5p in MSCs and MSC-exo, which was required for the expression of S100A6 in BCs. Importantly, silencing of miR-21-5p expression in MSCs and MSC-exo abolished the resistance of BCs to Dox, indicating an exosomal miR-21-5p-regulated S100A6 in chemoresistance. Our study thus uncovered a novel mechanistic insight into the role of MSC-secreted exosome in the development of chemoresistance in the tumor microenvironment.

Leptin promotes bone metastasis of breast cancer by activating the SDF-1/CXCR4 axis.

Obesity is associated with an increased risk of tumorigenesis, and increased leptin levels can promote tumor metastasis. However, the effects of leptin on bone metastasis in breast cancer are not fully understood. Here, we examined leptin receptor expression and bone metastasis in tissue samples from 96 breast cancer patients. In addition, we investigated the effects of leptin on the metastatic capacity of breast cancer cells invitro using a transwell assays. The results indicated that higher leptin receptor levels in breast cancer cells are associated with increased incidence of bone metastasis in breast cancer patients. Additionally, leptin promoted migration and invasion of breast cancer cells. The SDF-1/CXCR4 axis activated by leptin also promoted bone metastasis of breast cancer. Finally, increased CXCR4 expression was accompanied by high leptin receptor expression in bone metastatic tissues from breast cancer patients. These results indicate that leptin induces bone metastasis of breast cancer by activating the SDF-1/CXCR4 axis.

Aspirin alleviates hepatic fibrosis by suppressing hepatic stellate cells activation via the TLR4/NF-κB pathway.

Hepatic fibrosis arises from a sustained wound-healing response to chronic liver injury. Because the occurrence and development of hepatic fibrosis is always associated with chronic inflammation, controlling inflammation within the liver may be an effective means of controlling the development and progression of hepatic fibrosis. Aspirin is a non-steroidal anti-inflammatory drug used to relieve both inflammatory symptoms and pain. The results of our study showed that aspirin significantly attenuated hepatic inflammation and fibrosis. Aspirin effectively inhibited the activation and proliferation of hepatic stellate cells (HSCs), which led to downregulation of inflammatory factors, including IL-6 and TNF-α in those cells. Aspirin also downregulated expression of Toll-like receptor-4 (TLR4) on HSCs, as well as its downstream mediators, MyD88 and NF-κB. The results of our study demonstrate aspirin's potential to inhibit the development of hepatic fibrosis and the molecular mechanism by which it acts. They suggest aspirin may be an effective therapeutic agent for the treatment of hepatic fibrosis.

Gene polymorphisms of TLR2 and TLR3 in HBV clearance and HBV-related hepatocellular carcinoma in a Chinese male population.

BACKGROUND: The Toll-like receptor plays an essential role in controlling immunity and inflammation. This study was to investigate the relationships of genetic variants in TLR2 and TLR3 with hepatitis B virus (HBV) natural clearance and HBV-related hepatocellular carcinoma (HCC) risk in a Chinese male population. METHODS: We analyzed 5 polymorphisms of TLR2 (rs3804099 and rs3804100) and TLR3 (rs5743305, rs3775296 and rs3775291) in a population consisting of 686 participants with HBV natural clearance, 293 chronic HBV carriers and 395 HBV-positive HCC patients, using the improved multiplex ligase detection reaction method. RESULTS: After adjustment for age and smoking and drinking status, no associations were observed either between the 5 single-nucleotide polymorphisms (SNPs) and the HBV natural clearance participants, or between the 5 SNPs and HCC patients. Whereas the stratified analysis showed that under the dominant models, nondrinkers with TLR2 rs3804100 and participants younger than 40 years old with TLR3 rs3775291 were significantly associated with HCC risk when compared with persistent HBV carriers (adjusted odd ratio [OR] = 0.49, 95% confidence interval [95% CI], 0.31-0.78, p = 0.003; and adjusted OR = 0.50, 95% CI, 0.29-0.86, p = 0.013, respectively). Furthermore, the TTTCT haplotype was found to promote the progress of HBV clearance and inhibit development of HBV-related HCC (OR = 0.77, 95% CI, 0.61-0.97, p = 0.029; and OR = 0.72, 95% CI, 0.55-0.94, p = 0.016, respectively). And the CCACC and CCTCT haplotypes were observed to decrease susceptibility to HCC (OR = 0.64, 95% CI, 0.40-1.00, p = 0.048; and OR = 0.43, 95% CI, 0.28-0.68, p<0.001, respectively). CONCLUSIONS: This study revealed that TLR2 rs3804100 and TLR3 rs3775291 polymorphisms may be protective factors for HBV-related HCC.

Mesenchymal stem cells with Sirt1 overexpression suppress breast tumor growth via chemokine-dependent natural killer cells recruitment.

Mesenchymal stem cells (MSCs) are generally used in regenerative medicine, tissue engineering and therapy for immune disorder diseases. However, due to the immunosuppressive function of MSCs, the application of MSCs in breast cancer therapy remains limited. Sirt1 is the closest mammalian homologue of the yeast enzyme Sir2 which has an established capacity to influence yeast replicative lifespan. In this study, we demonstrated the effect of MSCs with Sirt1 overexpression (MSCs-Sirt1) in mice bearing 4T1 breast cancer and investigated the underlying mechanism. Firstly, we found that MSCs could accelerate breast tumor growth with promoted proliferation and inhibited apoptosis, whereas MSCs-Sirt1 significantly suppressed tumor growth with proliferation inhibition and apoptosis promotion. Moreover, we detected that NK cells were the prominent antitumor effectors for the MSCs-Sirt1-induced antitumor activity. Besides that, CXCL10 and IFN-γ showed the high level expression in MSCs-Sirt1 treatment group. The impulsive effect of MSCs-Sirt1 on 4T1 cells in vivo could be reversed by inhibition of CXCL10 and IFN-γ. Overall, our results suggest that MSCs-Sirt1 can effectively inhibit breast tumor growth via the recruitment of NK cells in tumor inflammatory microenvironment.

Inhibition of autophagy enhances the radiosensitivity of nasopharyngeal carcinoma by reducing Rad51 expression.

Radiotherapy has long been considered as the mainstay of treatment for nasopharyngeal carcinoma (NPC). However, locoregional recurrence or distant metastasis may occur in some patients due to the radiation resistance of cancer cells. Autophagy plays a vital role in protecting cells against radiation. However, the mechanism of autophagy in radiation therapy remains obscure. In the present study, we demonstrated that suppression of autophagy related 5 (Atg5) aggravated ionizing radiation (IR)-induced DNA damage and apoptosis in human NPC cells without accelerating the cell cycle, whereas regulation of the cell cycle has been widely regarded as the most important determinant of IR sensitivity. Further study showed that inhibition of autophagy suppressed the mRNA expression of Rad51, a key protein of homologous recombination that has been demonstrated to play a critical role in the repair of DNA double-strand breaks induced by radiation. Moreover, suppression of Atg5 had no impact on the radiosensitivity when cells were pre-treated by the Rad51 inhibitor, and the enhanced radiosensitivity by Atg5 suppression was reversed by overexpression of Rad51 in human NPC cells. Our results suggest that inhibition of autophagy enhances the susceptibility of NPC cells to radiation by reducing Rad51 expression. Therefore, Rad51 targeted therapy may be investigated as a potential novel agent for the adjuvant treatment of traditional radiation of NPC.