Pharmacological targets of SGLT2 inhibition on prostate cancer mediated by circulating metabolites: a drug-target Mendelian randomization study.

Background: The relationship between sodium-glucose cotransporter 2 (SGLT2) inhibitors and prostate cancer is still unknown. Although these inhibitors can influence tumor glycolysis, the underlying mechanism requires further exploration. Methods: A two-sample two-step MR was used to determine 1) causal effects of SGLT2 inhibition on prostate cancer; 2) causal effects of 1,400 circulating metabolites or metabolite ratios on prostate cancer; and 3) mediation effects of these circulating metabolites. Genetic proxies for SGLT2 inhibition were identified as variants in the SLC5A2 gene and glycated hemoglobin level (HbA1c). Additionally, positive control analysis on type 2 diabetes mellitus (T2DM) was conducted to test the selection of genetic proxies. Phenome Wide Association Study (PheWAS) and MR-PheWAS analysis were used to explore potential treatable diseases and adverse outcomes of SGLT2 inhibitors. Results: Genetically predicted SGLT2 inhibition (per 1 SD decrement in HbA1c) was associated with reduced risk of T2DM [odds ratio (OR) = 0.66 (95% CI 0.53, 0.82), P = 1.57 × 10-4]; prostate cancer [0.34 (0.23, 0.49), P = 2.21 × 10-8] and prostate-specific antigen [0.26 (0.08, 0.81), P = 2.07 × 10-2]. The effect of SGLT2 inhibition on prostate cancer was mediated by uridine level, with a mediated proportion of 9.34% of the total effect. In MR-PheWAS, 65 traits were found to be associated with SLGT2 inhibitors (P < 1.78 × 10-5), and among them, 13 were related to diabetes. Conclusion: Our study suggested that SGLT2 inhibition could lower prostate cancer risk through uridine mediation. More mechanistic and clinical research is necessary to explore how uridine mediates the link between SGLT2 inhibition and prostate cancer.

Ampelopsin induces MDA-MB-231 cell cycle arrest through cyclin B1-mediated PI3K/AKT/mTOR pathway in vitro and in vivo.

Breast cancer is one of the most common malignant tumors in women and it is the most frequently diagnosed cancer in the world. Ampelopsin (AMP) is a purified component from the root of Ampelopsis grossedentata. It is reported that AMP could significantly inhibit the proliferation of breast cancer cells. However, the antitumor mechanism against breast cancer has not yet been fully elucidated. The purpose of this work was to study the role of AMP against breast cancer MDA-MB-231 cells and to further investigate the underlying mechanism. PI3K/AKT/mTOR plays a very important role in tumor cell growth and proliferation and we hypothesize that AMP may inhibit this pathway. In the present work, the results showed that AMP could significantly inhibit the growth of breast cancer MDA-MB-231 cells in vitro and in vivo. In addition, treatment with AMP decreased the levels of PI3K, AKT and mTOR, as well as cyclin B1 expression, followed by p53/p21 pathway activation to arrest the cell cycle at G2/M. Moreover, it demonstrated a positive association between cyclin B1 and PI3K/AKT/mTOR levels. Importantly, this pathway was found to be regulated by cyclin B1 in MDA-MB-231 cells treated with AMP. Also, it was observed that cyclin B1 overexpression attenuated cell apoptosis and weakened the inhibitory effects of AMP on cell proliferation. Together, AMP could inhibit breast cancer MDA-MB-231 cell proliferation in vitro and in vivo, due to cell cycle arrest at G2/M by inactivating PI3K/AKT/mTOR pathway regulated by cyclin B1.

Effect of Stereotactic Body Radiation Therapy Combined with Thermoplastic Fixation on Set-Up Errors in Breast Cancer Patients Undergoing Radiotherapy.

Objective: To investigate the effect of stereotactic radiotherapy (SBRT) combined with thermoplastic fixation on set-up error in breast cancer (BC) patients undergoing radiotherapy. Methods: Ninety BC patients undergoing radiotherapy who were treated in our hospital (May 2019-May 2020) were selected as the research objects and equally divided into the experimental group and control group according to the order of hospitalization, with 45 patients in each group. The control group received conventional radiotherapy combined with breast bracket, and the experimental group received SBRT combined with thermoplastic fixation. The incidences of adverse reactions, 1-year survival rates, and set-up errors were compared between the two groups. Results: Compared with the control group, the experimental group had much lower total incidence of adverse reactions and remarkably higher 1-year survival rate. The translational errors (X direction, Y direction, and Z direction), translational errors after rotation (X direction, Y direction, and Z direction), and rotation errors (X direction, Y direction, and Z direction) in the experimental group were obviously lower compared with those in the control group. Conclusion: Implementing SBRT combined with thermoplastic fixation in BC patients undergoing radiotherapy can effectively improve set-up efficiency and treatment accuracy and reduce set-up errors. Compared with the breast bracket, the combination of SBRT and thermoplastic fixation has higher application value, and further studies are conducive to providing patients with a better solution plan.

Expression and clinical significance of matrix metalloproteinase-9 in lymphatic invasiveness and metastasis of breast cancer.

BACKGROUND: Matrix metalloproteinase 9 (MMP-9) is a type-IV collagenase that is highly expressed in breast cancer, but its exact role in tumor progression and metastasis is unclear. METHODS: MMP-9 mRNA and protein expression was examined by real-time reverse transcriptase PCR and immunohistochemical staining, respectively, in 41 breast cancer specimens with matched peritumoral benign breast epithelial tissue and suspicious metastatic axillary lymph nodes. Lymph vessels were labeled with D2-40 and lymphatic microvessel density (LMVD) was calculated. Correlation of MMP-9 protein expression with clinicopathological parameters and LMVD was also evaluated. RESULTS: MMP-9(+) staining in breast cancer specimens (35/41, 85.4%) was higher than in matched epithelium (21/41, 51.2%; P<0.05) and lymph nodes (13/41, 31.7%; P<0.001). Higher MMP-9 mRNA expression was also detected in tumor specimens compared with matched epithelial tissues and lymph nodes (P<0.05). Elevated MMP-9 expression was correlated with lymph node metastasis and LMVD (P<0.05). CONCLUSION: MMP-9 was overexpressed in breast cancer specimens compared with peritumoral benign breast epithelium and lymph nodes. Moreover, its expression in the matched epithelium and lymph nodes was positively associated with lymph node metastasis, and its expression in lymph nodes was positively associated with lymphangiogenesis in breast cancer. Thus, MMP-9 is a potential marker for breast cancer progression.

Expression and clinical significance of extracellular matrix protein 1 and vascular endothelial growth factor-C in lymphatic metastasis of human breast cancer.

BACKGROUND: Extracellular matrix protein 1 (ECM1) and vascular endothelial growth factor-C (VEGF-C) are secretory glycoproteins that are associated with lymphangiogenesis; these proteins could, therefore, play important roles in the lymphatic dissemination of tumors. However, very little is known about their potential roles in lymphangiogenesis. The aim of this study was to investigate whether correlations exist between ECM1 and VEGF-C in human breast cancer, lymphangiogenesis, and the clinicopathological characteristics of the disease. METHODS: ECM1 and VEGF-C mRNA and protein expression levels in 41 patients were investigated using real-time reverse transcriptase polymerase chain reaction (RT-PCR), or immunohistochemical (IHC) staining of breast cancer tissue, matched noncancerous breast epithelial tissues, and suspicious metastatic axillary lymph nodes. D2-40 labelled lymph vessels and lymphatic microvessel density (LMVD) were counted. Correlations between ECM1 or VEGF-C protein expression levels, LMVD, and clinicopathological parameters were statistically tested. RESULTS: The rate of ECM1 positive staining in breast cancer tissues was higher (31/41, 75.6%) than that in the corresponding epithelial tissues (4/41, 9.8%, P < 0.001) and lymph nodes (13/41, 31.7%, P < 0.001). Similarly, the VEGF-C expression rate in cancer specimens was higher (33/41, 80.5%) than in epithelial tissues (19/41, 46.3%, P < 0.01) or lymph nodes (15/41, 36.6%, P < 0.01). Higher ECM1 and VEGF-C mRNA expression levels were also detected in the tumor tissues, compared to the non-cancerous tissue types or lymph nodes (P < 0.05). ECM1 protein expression was positively correlated with the estrogen receptor status (P < 0.05) and LMVD (P < 0.05). LMVD in the ECM1- and VEGF-C-positive tumor specimens was higher than that in the tissue types with negative staining (P < 0.05). CONCLUSIONS: Both ECM1 and VEGF-C were overexpressed in breast cancer tissue samples. ECM1 expression was positively correlated with estrogen responsiveness and the metastatic properties of breast cancer. We conclude, therefore, that ECM1 and VEGF-C may have a synergistic effect on lymphangiogenesis to facilitate lymphatic metastasis of breast cancer.