Anthracycline-Free Neoadjuvant Chemotherapy Ensures Higher Rates of Pathologic Complete Response in Breast Cancer

Sexual dysfunction as a challenge in treated breast cancer: in-depth analysis and risk assessment to improve individual outcomes

The increasing number of breast cancer survivors has led to a greater emphasis on issues related to quality of life (QoL). Up to 75% of women treated for breast cancer (BC) report sexual disorders. However, most oncologists are not trained to recognize which patients are at high-risk of developing sexual disorders. Female sexual dysfunction (FSD) is common in patients with BC; we found that patients without FSD prior to BC treatment are at risk of developing FSD after treatment. Treatment of early BC relies on the combination of chemotherapy, surgery, and radiation therapy. All these treatments have side effects or sequelae identified as high-risk factors for the development of FSD. The choice of less toxic treatments in each modality could reduce the risk of FSD in some cases, without affecting the risk of recurrence or effectiveness. A comprehensive approach of BC must consider FSD as a determinant factor of QoL in survivors.

Pathological complete response following cisplatin or carboplatin-based neoadjuvant chemotherapy for triple-negative breast cancer: A systematic review and meta-analysis

The addition of platinum compounds to standard neoadjuvant chemotherapy (NACT) for triple-negative breast cancer (TNBC) is highly controversial. Platinum agents, such as cisplatin and carboplatin, are DNA-damaging agents which exhibit activity in breast cancer, particularly in the TNBC subgroup. In order to assess the efficacy of each most representative platinum agent (cisplatin and carboplatin) in patients with TNBC treated with NACT, the present study performed a systematic review and meta-analysis of all available published studies on TNBC. A search of PubMed was performed to identify studies that investigated platinum-based NACT in patients with TNBC. The primary endpoints were the pooled rate of the pathological complete response (pCR) between cisplatin vs. carboplatin-based NACT. A total of 24 studies were selected (17 studies for carboplatin and 6 studies for cisplatin and 1 study with both carboplatin and cisplatin, with 20 prospective studies) for the analysis of 1,711 patients with TNBC. Overall, the pooled rate of pCR in patients treated with platinum-based NACT was 48%. No significant differences were observed between the rates of pCR obtained under carboplatin vs cisplatin treatment. The carboplatin pCR rate was 0.470 [95% confidence interval (CI), 0.401-0.539], while the cisplatin pCR rate was 0.473 (95% CI, 0.379-0.568). The comparison between these two categories revealed no significant differences (P=0.959). In the whole, the present study demonstrates that neoadjuvant platinum-based chemotherapy improves the pCR rate in patients with TNBC, regardless of the platinum agent used. Carboplatin may thus represent a viable option due to its more favorable toxicity profile.

Luteolin Prevents Cardiac Dysfunction and Improves the Chemotherapeutic Efficacy of Doxorubicin in Breast Cancer

Background: Doxorubicin (Dox) is one of the most effective chemotherapy agents used in the treatment of solid tumors and hematological malignancies. However, it causes dose-related cardiotoxicity that may lead to heart failure in patients. Luteolin (Lut) is a common flavonoid that exists in many types of plants. It has been studied for treating various diseases such as hypertension, inflammatory disorders, and cancer. In this study, we evaluated the cardioprotective and anticancer effects of Lut on Dox-induced cardiomyopathy in vitro and in vivo to explore related mechanisms in alleviating dynamin-related protein (Drp1)-mediated mitochondrial apoptosis.

Methods: MTT and LDH assay were used to determine the viability and toxicity of cardiomyocytes treated with Dox and Lut. Flow cytometry was used to examine ROS levels, and electron and confocal microscopy was employed to assess the mitochondrial morphology. The level of apoptosis was examined by Hoechst 33258 staining. The protein levels of myocardial fission protein and apoptosis-related protein were examined using Western blot. Transcriptome analysis of the protective effect of Lut against Dox-induced cardiac toxicity in myocardial cells was performed using RNA sequencing technology. The protective effects of Lut against cardiotoxicity mediated by Dox in zebrafish were quantified. The effect of Lut increase the antitumor activity of Dox in breast cancer both in vitro and in vivo were further employed.

Results: Lut ameliorated Dox-induced toxicity in H9c2 and AC16 cells. The level of oxidative stress was downregulated by Lut after Dox treatment of myocardial cells. Lut effectively reduced the increased mitochondrial fission post Dox stimulation in cardiomyocytes. Apoptosis, fission protein Drp1, and Ser616 phosphorylation were also increased post Dox and reduced by Lut. In the zebrafish model, Lut significantly preserved the ventricular function of zebrafish after Dox treatment. Moreover, in the mouse model, Lut prevented Dox-induced cardiotoxicity and enhanced the cytotoxicity in triple-negative breast cancer by inhibiting proliferation and metastasis and inducing apoptosis.

Knockdown of Mtfp1 can minimize doxorubicin cardiotoxicity by inhibiting Dnm1l-mediated mitochondrial fission

The long-term usage of doxorubicin (DOX) is largely limited due to the development of severe cardiomyopathy. Many studies indicate that DOX-induced cardiac injury is related to reactive oxygen species generation and ultimate activation of apoptosis. The role of novel mitochondrial fission protein 1 (Mtfp1) in DOX-induced cardiotoxicity remains elusive. Here, we report the pro-mitochondrial fission and pro-apoptotic roles of Mtfp1 in DOX-induced cardiotoxicity. DOX up-regulates the Mtfp1 expression in HL-1 cardiac myocytes. Knockdown of Mtfp1 prevents cardiac myocyte from undergoing mitochondrial fission, and subsequently reduces the DOX-induced apoptosis by preventing dynamin 1-like (Dnm1l) accumulation in mitochondria. In contrast, when Mtfp1 is overexpressed, a suboptimal dose of DOX can induce a significant percentage of cells to undergo mitochondrial fission and apoptosis. These data suggest that knocking down of Mtfp1 can minimize the cardiomyocytes loss in DOX-induced cardiotoxicity. Thus, the regulation of Mtfp1 expression could be a novel therapeutic approach in chemotherapy-induced cardiotoxicity.

Mitochondrial protein 18 (MTP18) plays a pro-apoptotic role in chemotherapy-induced gastric cancer cell apoptosis

One of the severe limitations of chemotherapy is the development of drug resistance. However, the mechanisms underlying chemotherapy resistance remain to be elucidated. Mitochondrial mediated apoptosis is a form of cell death induced by chemotherapy. Several chemotherapeutic agents have been shown to induce mitochondrial fission, and finally activate the apoptosis cascade in various cancer cells. Here, we report that the mitochondrial membrane protein 18 (MTP18) induced mitochondrial fragmentation in gastric cancer cells under doxorubicin (DOX) exposure. Upon over-expression of MTP18, a sub-cytotoxic dose of DOX could sensitize a significant number of cells to undergo mitochondrial fission and subsequent apoptosis. These findings suggest that MTP18 can enhance the sensitivity of gastric cancer cells to DOX. Mechanistically, we found that MTP18 enriched dynamic-related protein 1 (DRP1) accumulation in mitochondria and it was responsible for mediating DOX-induced signaling required for mitochondrial fission. Intriguingly, MTP18 expression was downregulated during DOX treatment. Thus, down-regulation of MTP18 expression could be one of the resistance factors interfering with DOX-induced apoptosis in gastric cancer cells.