Prognostic Factors in Patients with Stage II/III Breast Cancer Treated with Adjuvant Extension of Neoadjuvant Chemotherapy: A Retrospective Cohort Study with Ten-Years of Follow-Up Data

Novel role of COX6c in the regulation of oxidative phosphorylation and diseases

Cytochrome c oxidase subunit VIc (COX6c) is one of the most important subunits of the terminal enzyme of the respiratory chain in mitochondria. Numerous studies have demonstrated that COX6c plays a critical role in the regulation of oxidative phosphorylation (OXPHOS) and energy production. The release of COX6c from the mitochondria may be a hallmark of the intrinsic apoptosis pathway. Moreover, The changes in COX6c expression are widespread in a variety of diseases and can be chosen as a potential biomarker for diagnosis and treatment. In light of its exclusive effects, we present the elaborate roles that COX6c plays in various diseases. In this review, we first introduced basic knowledge regarding COX6c and its functions in the OXPHOS and apoptosis pathways. Subsequently, we described the regulation of COX6c expression and activity in both positive and negative ways. Furthermore, we summarized the elaborate roles that COX6c plays in various diseases, including cardiovascular disease, kidney disease, brain injury, skeletal muscle injury, and tumors. This review highlights recent advances and provides a comprehensive summary of COX6c in the regulation of OXPHOS in multiple diseases and may be helpful for drug design and the prediction, diagnosis, treatment, and prognosis of diseases.

Estrogen Enhances the Expression of the Multidrug Transporter Gene ABCG2-Increasing Drug Resistance of Breast Cancer Cells through Estrogen Receptors

Background: Multidrug resistance is a major obstacle in the successful therapy of breast cancer. Studies have proved that this kind of drug resistance happens in both human cancers and cultured cancer cell lines. Understanding the molecular mechanisms of drug resistance is important for the reasonable design and use of new treatment strategies to effectively confront cancers. Results: In our study, ATP-binding cassette sub-family G member 2 (ABCG2), adenosine triphosphate (ATP) synthase and cytochrome c oxidase subunit VIc (COX6C) were over-expressed more in the MCF-7/MX cell line than in the normal MCF7 cell line. Therefore, we believe that these three genes increase the tolerance of MCF7 to mitoxantrone (MX). The data showed that the high expression of COX6C made MCF-7/MX have more stable on mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) expression than normal MCF7 cells under hypoxic conditions. The accumulation of MX was greater in the ATP-depleted treatment MCF7/MX cells than in normal MCF7/MX cells. Furthermore, E2 increased the tolerance of MCF7 cells to MX through inducing the expression of ABCG2. However, E2 could not increase the expression of ABCG2 after the inhibition of estrogen receptor α (ERα) in MCF7 cells. According to the above data, under the E2 treatment, MDA-MB231, which lacks ER, had a higher sensitivity to MX than MCF7 cells. Conclusions: E2 induced the expression of ABCG2 through ERα and the over-expressed ABCG2 made MCF7 more tolerant to MX. Moreover, the over-expressed ATP synthase and COX6c affected mitochondrial genes and function causing the over-expressed ABCG2 cells pumped out MX in a concentration gradient from the cell matrix. Finally lead to chemoresistance.

Predictive and prognostic value of ER-α36 expression in breast cancer patients treated with chemotherapy

BACKGROUND

This study is to investigate the predictive and prognostic value of ER-α36 expression in breast cancer patients treated with chemotherapy.

METHODS

ER-α36 expression in 120 breast cancer tumors was assessed by an immunohistochemistry assay. All patients were divided into two groups according to the chemotherapy procedure: group A, 50 patients who underwent neoadjuvant chemotherapy before surgery; group B, 70 patients who were performed adjuvant chemotherapy after surgery, and they all took at least two cycles of anthracycline-based and/or paclitaxel-based chemotherapy after surgery. The therapy effect on group A patients was evaluated two cycles later by Response Evaluation Criteria in Solid Tumors version 1.0 (RECIST 1.0).

RESULTS

ER-α36 protein was positively expressed in 51 tumor specimens (42.5%) and no correlation was found between the expression of ER-α 36 and the expression of the full-length ER-α (ER-α66), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER-2), Ki-67, tumor sizes, and the numbers of lymph node metastasis. Patients with ER-α36 negative expression tumors treated with the neoadjuvant chemotherapy had a higher remission rate [partial response: stable: progressed (n) 25:3:1 vs.11:9:1; P=0.009], a better response (86% vs. 52%; P=0.009), and a more favorable outcomes in triple-negative breast cancer patients compared to ER-α36 positive patients and ER-α36 negative expression was correlated with DFS in patients treated with neoadjuvant chemotherapy.

CONCLUSIONS

ER-α36 negative tumors benefit more from neoadjuvant chemotherapy and have better prognosis, which may warrant further studies with larger size of the sample.

Treatment outcome in patients with stage III breast cancer treated with neoadjuvant chemotherapy

Despite the good responses of patients (pts) with stage III breast cancer to neoadjuvant chemotherapy (NAC), most eventually relapse and have a poor prognosis. We investigated the prognostic indicators in pts with stage III breast cancer treated with NAC, using epirubicin and/or docetaxel. A total of 22 women with stage III breast cancer underwent NAC between January 2005 and May 2011. The regimens of NAC comprised ED (epirubicin 60 mg/m² and docetaxel 60 mg/m²) in 10 cases, FEC (fluorouracil 500 mg/m², epirubicin 75-100 mg/m² and cyclophosphamide 500 mg/m²) in 10 cases and EC (epirubicin 60 mg/m² and cyclophosphamide 600 mg/m²) in two cases. Following four cycles of each regimen, a further four cycles of D (docetaxel 70 mg/m²) were undertaken in nine cases. Subsequent to the completion of NAC and surgery, we assessed the clinicopathological results and performed prognostic analyses. Statistical analyses concerning disease-free survival (DFS) or overall survival (OS) were conducted by a Cox proportional hazard model. The median survival time was 66 months and there were 12 distant metastases and two local recurrences. Multivariate analyses showed the number of metastatic axillary lymph nodes (ALNs) [hazard ratio (HR), 1.079; P=0.023] was correlated with DFS, while the Ki-67 labeling index (HR, 1.109; P=0.042) and the number of meta-static ALNs (HR, 1.087; P=0.023) were correlated with OS. In conclusion, even if pts with stage III breast cancer show good responses to NAC using epirubicin and/or docetaxel, the majority eventually relapse and have a poor prognosis. The Ki-67 labeling index and the number of involved ALNs are suggested as prognostic indicators in stage III breast cancer.

Gene silencing of FANCF potentiates the sensitivity to mitoxantrone through activation of JNK and p38 signal pathways in breast cancer cells

Fanconi anemia complementation group-F (FANCF) is a key factor to maintain the function of FA/BRCA, a DNA-damage response pathway. However, the functional role of FANCF in breast cancer has not been elucidated. In this study, we examined the effects and mechanisms of FANCF-RNAi on the sensitivity of breast cancer cells to mitoxantrone (MX). FANCF silencing by FANCF-shRNA blocked functions of FA/BRCA pathway through inhibition of FANCD2 mono-ubiquitination in breast cancer cell lines MCF-7 and T-47D. In addition, FANCF shRNA inhibited cell proliferation, induced apoptosis, and chromosome fragmentation in both breast cancer cells. We also found that FANCF silencing potentiated the sensitivity to MX in breast cancer cells, accompanying with an increase in intracellular MX accumulation and a decrease in BCRP expression. Furthermore, we found that the blockade of FA/BRCA pathway by FANCF-RNAi activated p38 and JNK MAPK signal pathways in response to MX treatment. BCRP expression was restored by p38 inhibitor SB203580, but not by JNK inhibitor SP600125. FANCF silencing increased JNK and p38 mediated activation of p53 in MX-treated breast cancer cells, activated the mitochondrial apoptosis pathway. Our findings indicate that FANCF shRNA potentiates the sensitivity of breast cancer cells to MX, suggesting that FANCF may be a potential target for therapeutic strategies for the treatment of breast tumors.

Preclinical models in electrochemotherapy: the role of veterinary patients

Electrochemotherapy is a tumor treatment that adapts the systemic or local delivery of anticancer drugs by the application of permeabilizing electric pulses with appropriate amplitude and waveforms. This allows the use of lipophobic drugs, which frequently have a narrow therapeutic index, with a decreased morbidity for the patient, while maintaining appropriate anticancer efficacy. Electrochemotherapy is used in humans for the treatment of cutaneous neoplasms or the palliation of skin tumor metastases, and a standard operating procedure has been devised. In veterinary oncology, the electrochemotherapy approach is gaining popularity, becoming a first-line treatment in consideration of its high efficacy and low toxicity. This review summarizes the state of the art in veterinary oncology as a preclinical model.