Neoadjuvant therapy for locally advanced breast cancer: Focus on chemotherapy and biological targeted treatments' armamentarium

How Can Oncoplastic Breast Surgery Contribute to the Management of Locally Advanced Breast Cancer in Sub-Saharan Africa?

Background

Because of resource constrains in sub-Saharan African countries, breast-conserving surgery (BCS) has no role in patients with locally advanced breast cancer (LABC) following neoadjuvant chemotherapy (NACT), and mastectomy remains the standard surgical treatment for these patients.

Objectives

The first objective of the study was to assess the safety of oncoplastic BCS in patients with LABC who showed good clinical response to NACT in a breast center with enhanced level of resources in Sudan. The second objective was to assess the cosmetic outcome.

Patients and Methods

Two hundred and fifty patients with LABC were treated with NACT at Khartoum Breast Care Center during the period 2013-2019. Out of this, 52 patients were surgically treated with oncoplastic breast-conserving surgery. Kaplan-Meier curve was used to calculate the survival rates. The cosmetic outcome was subjectively assessed by the Harris scale.

Results

The median follow-up period was 53 months. The 3- and 5-years distant metastasis-free survival rates were 92.9% and 82.2%, respectively. One patient developed regional recurrence, and 6 patients developed distant metastasis. Eighty percentage of patients were admitted to have good to excellent cosmetic outcome.

Conclusion

This Sudanese experience showed that oncoplastic BCS is oncologically safe and aesthetically satisfactory in patients with LABC who demonstrated good clinical response to NACT in a setting with enhanced levels of resources for breast cancer care.

Dynamic characterization of breast cancer response to neoadjuvant therapy using biophysical metrics of spatial proliferation

Current tools to assess breast cancer response to neoadjuvant chemotherapy cannot reliably predict disease eradication, which if possible, could allow early cessation of therapy. In this work, we assessed the ability of an image data-driven mathematical modeling approach for dynamic characterization of breast cancer response to neoadjuvant therapy. We retrospectively analyzed patients enrolled in the I-SPY 2 TRIAL at the Atrium Health Wake Forest Baptist Comprehensive Cancer Center. Patients enrolled on the study received four MR imaging examinations during neoadjuvant therapy with acquisitions at baseline (T₀), 3-weeks/early-treatment (T₁), 12-weeks/mid-treatment (T₂), and completion of therapy prior to surgery (T₃). We use a biophysical mathematical model of tumor growth to generate spatial estimates of tumor proliferation to characterize the dynamics of treatment response. Using histogram summary metrics to quantify estimated tumor proliferation maps, we found strong correlation of mathematical model-estimated tumor proliferation with residual cancer burden, with Pearson correlation coefficients ranging from 0.88 and 0.97 between T₀ and T₂, representing a significant improvement from conventional assessment methods of change in mean apparent diffusion coefficient and functional tumor volume. This data shows the significant promise of imaging-based biophysical mathematical modeling methods for dynamic characterization of patient-specific response to neoadjuvant therapy with correlation to residual disease outcomes.

A Novel Model Incorporating Tumor Stiffness, Blood Flow Characteristics, and Ki-67 Expression to Predict Responses After Neoadjuvant Chemotherapy in Breast Cancer

Objective

To investigate the ability of tumor stiffness, tumor blood flow, and Ki-67 expression alone or in combination in predicting the pathological response to neoadjuvant chemotherapy (NACT) in breast cancer.

Patients and Methods

This prospective cohort study included 145 breast cancer patients treated with NACT. Tumor stiffness (maximum stiffness (Emax), mean stiffness (Emean)), blood score (BS), and their relative changes, were evaluated before (t0), during (t1-t5), and at the end of NACT (t6) by shear-wave elastography and optical imaging. Ki-67 expression was quantitatively evaluated by immunohistochemistry using core biopsy specimens obtained before NACT. Pathological responses were evaluated by residual cancer burden. The ability of tumor stiffness, BS, Ki-67, and predRCB-which combined ΔEmean (t2) (the relative changes in Emean after the second NACT cycle), BS2 (BS after the second NACT cycle), and Ki-67-in predicting tumor responses was compared using receiver operating characteristic curves and the Z-test.

Results

Tumor stiffness and BS decreased during NACT. ΔEmean (t2), BS2, and Ki-67 had better predictive performance than other indexes in identifying a favorable response (AUC = 0.82, 0.81, and 0.80) and resistance responses (AUC = 0.85, 0.79, and 0.84), with no significant differences between the three (p > 0.05). PredRCB had better predictive performance than any parameter alone for a favorable response (AUC = 0.90) and resistance (AUC = 0.93).

Conclusion

Tumor stiffness, BS, and Ki-67 expression showed good and similar abilities for predicting the pathological response to NACT, and predRCB was a significantly better predictor than each index alone. These results may help design therapeutic strategies for breast cancer patients undergoing NACT.

Clinical outcome and predictive factors for docetaxel and epirubicin neoadjuvant chemotherapy of locally advanced breast cancer

BACKGROUND/AIMS

We evaluated the efficacy of docetaxel and epirubicin as neoadjuvant chemotherapy in locally advanced breast cancer and assessed the predictive factors for response to neoadjuvant chemotherapy and prognostic factors related to relapse-free survival.

METHODS

Forty patients who received docetaxel and epirubicinas neoadjuvant chemotherapy for locally advanced breast cancer were evaluated retrospectively. Neoadjuvant chemotherapy consisted of intravenous injection of 75 mg/m2 docetaxel and 60 mg/m2 epirubucin on day 1, every 21 days, and two to six cycles.

RESULTS

Twenty-five (62.5%) patients showed a partial response, and 15 (37.5%) patients showed a stable disease in the first response evaluation after two or three cycles of neoadjuvant chemotherapy. In the second response evaluation of nine patients who received six cycles of neoadjuvant chemotherapy, one patient achieved a complete response, but two patients with hormone receptor-negative, human epidermal growth factor receptor 2-positive breast cancer experienced disease progression. Twenty-five (62.5%) patients experienced downstaging after neoadjuvant chemotherapy. Patients with > 20% pretreatment Ki-67 and decrease of Ki-67 between pre- and post-neoadjuvant chemotherapy showed a trend for better response. In multivariate analysis, advanced pathological stage showed a significant negative effect on relapse-free survival.

CONCLUSION

Docetaxel and epirubicin neoadjuvant chemotherapy showed a good response in locally advanced breast cancer. Pretreatment Ki-67 and change of Ki-67 may play a role as predictive factor for response to neoadjuvant chemotherapy.

A Predictor of Pathological Complete Response to Neoadjuvant Chemotherapy Stratifies Triple Negative Breast Cancer Patients with High Risk of Recurrence

We developed a test to predict which patients will achieve pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) and which will have residual disease (RD). Gene expression data from pretreatment biopsies of patients with all breast cancer subtypes were combined into a 519-patient cohort containing 177 TNBC patients. Two RNA classifiers of 16 genes each were sequentially applied to the total cohort, classifying patients into 3 distinct classes. The test performance was further validated in an independent 304-patient cohort. The test accurately identified 70.5% (79/112) of pCR and 83.5% (340/407) of RD patients in the total population, and 75.0% (45/60) of pCR and 75.2% (88/117) of RD patients in the TNBC subset. For the independent cohort, the test identified 91.5% RD patients in the total population and 86.2% RD patients in the TNBC subset. However, the identification of pCR in both total and TNBC population are as low as 21.1% and 30%, respectively. The TNBC RD patients were subdivided by our classifiers, with one class showing significantly higher levels of Ki67 expression and having significantly poorer survival rates than the other classes. This stratification of patients may allow predicted residual disease classes to be assigned an alternative therapy.

Impact of Radicality Versus Timing of Surgery in Patients with Advanced Ovarian Cancer (Stage III C) Undergoing CRS and HIPEC-a Retrospective Study by INDEPSO

HIPEC in addition to interval CRS has shown a survival benefit of 12 months compared to CRS alone. However, there are many controversial issues pertaining to CRS itself which should be addressed first. To compare NACT and primary CRS approaches when CRS is categorized according to the extent of resection. To evaluate the feasibility of performing HIPEC at these two time points. A retrospective analysis of patients with stage III C ovarian cancer undergoing primary and interval CRS + HIPEC was performed. The surgical approach for interval CRS was classified as (1) resection of sites of residual disease alone or (2) resection of sites involved before NACT. The morphological response was divided into different categories, and surgeons had to state what they consider residual disease and what they do not. From January 2013 to December 2017, 54 patients were included (18-primary; 36-interval). Median PCI 11 vs 6.5 (p = 0.07); CC-0 was obtained in 77.7%. Three surgeons resected previously involved sites; three sites of residual disease only. All surgeons resected areas of scarring. Twenty percent patients had residual disease in "normal-looking" peritoneum. Morbidity (p = 0.09), median OS (p = 0.71), and median DFS (p = 0.54) were similar in the two groups. Early recurrence occurred in 50% with resection of residual disease alone compared to 16.6% when previous disease sites were resected (p = 0.07). Interval CRS should be performed to resect sites involved prior to NACT and not just sites of residual disease. HIPEC can be performed in both primary/interval settings with acceptable morbidity.

Co-Delivery of Gemcitabine and Paclitaxel in cRGD-Modified Long Circulating Nanoparticles with Asymmetric Lipid Layers for Breast Cancer Treatment

Combination chemotherapy is a common clinical practice in cancer treatment. Here, cyclic RGD (arginylglycylaspartic acid) peptide was introduced to the surface of lipid/calcium/phosphate (LCP) asymmetric lipid layer nanoparticles for the co-delivery of paclitaxel (PTX) and gemcitabine monophosphate (GMP) (P/G-NPs). The sphere-like morphology of P/G-NPs displays a well-distributed particle size, and high entrapment efficiency and drug loading for both PTX and GMP, with a positive zeta potential. P/G-NPs were stable for up to 15 days. The cellular uptake of these cyclic RGD-modified nanoparticles was significantly higher than that of unmodified nanoparticles over 2 h incubation. Compared with the combination of free PTX and GMP (P/G-Free), P/G-NPs exhibited a longer circulation lifetime and improved absorption for PTX and GMP. Polyethylene glycol was responsible for a higher plasma concentration and a decreased apparent volume of distribution (V_z). Nanoparticles enhanced the drug accumulation in tumors compared with other major organs after 24 h. P/G-NPs nearly halted tumor growth, with little evidence of general toxicity, whereas P/G-Free had only a modest inhibitory effect at 16 mg/kg of GMP and 2.0 mg/kg of PTX. Increased levels of apoptosis within tumors were detected in P/G-NPs group by approximately 43.6% (TUNEL assay). When compared with GMP NPs, PTX NPs, and P/G-Free, P/G-NPs decreased expression of B-cell lymphoma-2 and B-cell lymphoma-extra large proteins, and increased expression of cleaved poly-ADP-ribose polymerase-1. Calreticulin expression in tumors also increased upon the co-delivery of PTX and GMP. The antitumor effect of P/G-NPs is more powerful than P/G-Free, GMP NP, or PTX NP alone, without obvious toxicity.

The expression of aplysia ras homolog I (ARHI) and its inhibitory effect on cell biological behavior in esophageal squamous cell carcinoma

Background

Aplysia ras homolog I (ARHI) is a Ras-related maternally imprinted tumor suppressor gene. Loss of ARHI expression contributes to the malignant progression of various tumors. However, reports on the clinical implications and functional role of ARHI expression in esophageal squamous cell carcinoma (ESCC) are limited. This study examined the role of ARHI in ESCC.

Methods

In total, 81 patients diagnosed with ESCC based on histopathological evaluations who were subjected to surgical resection were included in the study. ARHI expression was analyzed by immunohistochemistry and western blotting, examining the correlations between ARHI expression and patient clinicopathological features. The functional effects of ARHI overexpression were examined using a Cell Counting Kit-8 assay, flow cytometry, a Transwell assay, wound healing, and western blotting in the ECA109 cell line.

Results

ARHI was highly expressed in 27.5% (22/81) of ESCC specimens (adjacent noncancerous tissues, 85.2%, 69/81; P<0.05). The ARHI expression level was significantly lower in patients with lymph node metastasis than in patients without (P<0.05). A Kaplan–Meier survival analysis showed that patients with low ARHI expression had shorter survival than patients with high expression (P<0.05), and a multivariate Cox analysis revealed that ARHI is an independent predictor of overall survival (P=0.029). Finally, overexpression of ARHI in ESCC cells indicates that ARHI suppresses proliferative capacity, invasive capacity, and cell cycle progression and may also suppress epithelial–mesenchymal transition and induce apoptosis and autophagy.

Conclusion

ARHI may be a prognostic biomarker and a potential therapeutic target in ESCC.

Prognostic value of stromal decorin expression in patients with breast cancer: a meta-analysis

BACKGROUND

Numbers of studies have investigated the biological functions of decorin (DCN) in oncogenesis, tumor progression, angiogenesis and metastasis. Although many of them aim to highlight the prognostic value of stromal DCN expression in breast cancer, some controversial results still exist and a consensus has not been reached until now. Therefore, our meta-analysis aims to determine the prognostic significance of stromal DCN expression in breast cancer patients.

METHODS

PubMed, EMBASE, the Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched for full-text literatures met out inclusion criteria. We applied the hazard ratio (HR) with 95% confidence interval (CI) as the appropriate summarized statistics. Q-test and I(2) statistic were employed to estimate the level of heterogeneity across the included studies. Sensitivity analysis was conducted to further identify the possible origins of heterogeneity. The publication bias was detected by Begg's test and Egger's test.

RESULTS

There were three English literatures (involving 6 studies) included into our meta-analysis. On the one hand, both the summarized outcomes based on univariate analysis (HR: 0.513; 95% CI: 0.406-0.648; P<0.001) and multivariate analysis (HR: 0.544; 95% CI: 0.388-0.763; P<0.001) indicated that stromal DCN expression could promise the high cancer-specific survival (CSS) of breast cancer patients. On the other hand, both the summarized outcomes based on univariate analysis (HR: 0.504; 95% CI: 0.389-0.651; P<0.001) and multivariate analysis (HR: 0.568; 95% CI: 0.400-0.806; P=0.002) also indicated that stromal DCN expression was positively associated with high disease-free survival (DFS) of breast cancer patients. No significant heterogeneity or publication bias was observed within this meta-analysis.

CONCLUSIONS

The present evidences indicate that high stromal DCN expression can significantly predict the good prognosis in patients with breast cancer. The discoveries from our meta-analysis have better be confirmed in the updated review pooling more relevant investigations in the future.

Upregulation of EGFR signaling is correlated with tumor stroma remodeling and tumor recurrence in FGFR1-driven breast cancer

Introduction

Despite advances in early detection and adjuvant targeted therapies, breast cancer is still the second most common cause of cancer mortality among women. Tumor recurrence is one of the major contributors to breast cancer mortality. However, the mechanisms underlying this process are not completely understood. In this study, we investigated the mechanisms of tumor dormancy and recurrence in a preclinical mouse model of breast cancer.

Methods

To elucidate the mechanisms driving tumor recurrence, we employed a transplantable Wnt1/inducible fibroblast growth factor receptor (FGFR) 1 mouse mammary tumor model and utilized an FGFR specific inhibitor, BGJ398, to study the recurrence after treatment. Histological staining was performed to analyze the residual tumor cells and tumor stroma. Reverse phase protein array was performed to compare primary and recurrent tumors to investigate the molecular mechanisms leading to tumor recurrence.

Results

Treatment with BGJ398 resulted in rapid tumor regression, leaving a nonpalpable mass of dormant tumor cells organized into a luminal and basal epithelial layer similar to the normal mammary gland, but surrounded by dense stroma with markedly reduced levels of myeloid-derived tumor suppressor cells (MDSCs) and decreased tumor vasculature. Following cessation of treatment the tumors recurred over a period of 1 to 4 months. The recurrent tumors displayed dense stroma with increased collagen, tenascin-C expression, and MDSC infiltration. Activation of the epidermal growth factor receptor (EGFR) pathway was observed in recurrent tumors, and inhibition of EGFR with lapatinib in combination with BGJ398 resulted in a significant delay in tumor recurrence accompanied by reduced stroma, yet there was no difference observed in initial tumor regression between the groups treated with BGJ398 alone or in combination with lapatinib.

Conclusion

These studies have revealed a correlation between tumor recurrence and changes of stromal microenvironment accompanied by altered EGFR signaling.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0649-1) contains supplementary material, which is available to authorized users.

Breast Cancer: Conventional Diagnosis and Treatment Modalities and Recent Patents and Technologies

Breast cancer is the most prevalent cancer among women worldwide. However, increased survival is due to the dramatic advances in the screening methods, early diagnosis, and breakthroughs in treatments. Over the course of the last decade, many acquisitions have taken place in this critical field of research in the pharmaceutical industry. Advances in molecular biology and pharmacology aided in better understanding of breast cancer, enabling the design of smarter therapeutics able to target cancer and respond to its microenvironment efficiently. Patents and research papers investigating diagnosis and treatment strategies for breast cancer using novel technologies have been surveyed for the past 15 years. Various nanocarriers have been introduced to improve the therapeutic efficacy of anticancer drugs, including liposomes, polymeric micelles, quantum dots, nanoparticles, and dendrimers. This review provides an overview of breast cancer, conventional therapy, novel technologies in the management of breast cancer, and rational approaches for targeting breast cancer.

HIGHLIGHTS

Breast cancer is the most common cancer in women worldwide. However, survival rates vary widely, optimistically heading toward a positive trend. Increased survival is due to the drastic shift in the screening methods, early diagnosis, and breakthroughs in treatments.Different strategies of breast cancer classification and staging have evolved over the years. Intrinsic (molecular) subtyping is essential in clinical trials and well understanding of the disease.Many novel technologies are being developed to detect distant metastases and recurrent disease as well as to assess response to breast cancer management.Intensive research efforts are actively ongoing to take novel breast cancer therapeutics to potential clinical application.Most of the recent research papers and patents discuss one of the following strategies: the development of new drug entities that specifically target the breast tumor cells; tailor designing a novel carrier system that can multitask and multifunction as a drug carrier, targeting vehicle and even as a diagnostic tool, direct conjugation of a therapeutic drug moiety with a targeting moiety, diagnostic moiety or pharmacokinetics altering moiety; or the use of innovative nontraditional approaches such as genetic engineering, stem cells, or vaccinations.

Pathological response rate in hormone-positive breast cancer patients treated with neoadjuvant FEC and triweekly docetaxel: a case series

We recently reported that neoadjuvant 5-FU, epirubicin, and cyclophosphamide (FEC) followed by weekly paclitaxel and/or trastuzumab induced a high pathological complete response (pCR) rate in hormone-negative patients. The present study examined the therapeutic efficacy of neoadjuvant FEC followed by triweekly docetaxel and/or trastuzumab in the treatment of hormone-positive patients. Between February 2012 and December 2013, 16 hormone-positive patients with local breast cancer (luminal A type: six patients; luminal B type: two patients; luminal HER2 type: eight patients) were included in the study. The histological type of the primary cancer was invasive ductal carcinoma in all patients. The cancer stages in the 16 women who received this regimen were stage I in five (31.3%), IIA in four (25.0%), IIB in five (31.3%), IIIB in one (6.3%), and IIIC in one (6.3%). Regarding clinical TNM classification, five patients were T1N0M0, one was T1N1M0, three were T2N0M0, five were T2N1M0, one was T3N2M0, and one was T4N0M0. The pCR was evaluated using resected tissue after neoadjuvant chemotherapy according to the evaluation criteria of the Japanese Breast Cancer Society. Patients were classified into pathologic responders (grade 2: 50.0% of all patients: 2/6 of luminal A type; 6/8 of Luminal HER2 type) and nonresponders (grades 0 and 1: 50.0% of all patients: 4/6 of luminal A type; 2/2 of luminal B type; 2/8 of luminal HER2 type) according to the grade of the tumor. The pCR rate was 0%. Hematologic and nonhematologic toxicity was reversible and manageable. This study demonstrated that neoadjuvant FEC followed by triweekly docetaxel and/or trastuzumab did induce a high pathologic response in luminal HER2 type, but not in luminal A and B types, and did not induce a high pCR rate in the hormone-positive patients.

Tau expression correlated with breast cancer sensitivity to taxanes-based neoadjuvant chemotherapy

The purpose of this study was to investigate the correlation between tau expression in primary breast cancer and sensitivity to taxanes during neoadjuvant chemotherapy in patients with breast cancer. We used immunohistochemistry to examine tau expression in breast cancer biopsies from 113 primary breast cancer patients and evaluated the correlation between tau expression and taxane sensitivity. Twenty-eight (24.78 %, 28/113) patients were positive for tau expression. After taxanes-based neoadjuvant chemotherapy, 40 patients achieved pathological complete response (pCR) (35.4 %). Among the 40 patients with pCR, five (12.5 %) were positive for tau expression. In univariate analysis, estrogen receptor (ER), progesterone receptor, human epidermal growth factor receptor 2 (HER2), and tau were found to be significantly predictive of a pCR (P = 0.001, 0.030, 0.002, and 0.025, respectively). Tau, ER, and HER2 status were significant for pCR on multivariate analysis (P = 0.025, 0.005, and 0.043, respectively). Tau expression was positively related to ER (P = 0.007) and progestin receptor (P = 0.008). In conclusion, tau protein expression correlated with breast cancer sensitivity to taxanes-based neoadjuvant chemotherapy; patients negative for tau expression were more likely to achieve pCR.

A clinical study on regional lymphatic chemotherapy using an activated carbon nanoparticle-epirubicin in patients with breast cancer

The purpose of this study was to understand the short-term therapeutic effects of an activated carbon nanoparticle-epirubicin suspension for regional lymphatic chemotherapy in patients with breast cancer. One hundred and twenty patients with stage I, II, or III primary breast cancer were randomly divided into three groups: the lymphatic chemotherapy group using the activated carbon nanoparticle-epirubicin suspension, the epirubicin control group, and the activated carbon control group. Each group of 40 patients was further divided into two subgroups with the drug injected either 24 or 48 h before surgery. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay was used to determine cancer cell apoptotic indices in metastatic lymph nodes. The epirubicin concentration in the black-stained lymph nodes in the lymphatic chemotherapy treatment group was 4,144.64 ± 2,426.44 ng/g, which is significantly higher than in the epirubicin control group (335.87 ± 212.82 ng/g, P < 0.001). The plasma epirubicin concentrations at 0.5, 1.5, and 24 h postinjection in the regional lymphatic chemotherapy treatment group were significantly lower than in the epirubicin control group (P < 0.001). Tolerable mild pain was observed at the injection area after administration of the epirubicin-activated carbon nanoparticle suspension. No regional necrosis or adverse effects were found. The TUNEL assay demonstrated that there was no significant difference in the apoptotic indices in the metastatic lymph nodes from the three groups. Performing lymphatic chemotherapy by regionally injecting the epirubicin-activated carbon nanoparticle suspension could significantly enhance the drug concentration in the stained lymph nodes and lower the plasma drug concentration. The epirubicin-activated carbon nanoparticle suspension has the ability to release the drug slowly in the lymph nodes and, as a result, can prolong the chemotherapeutic effects.

The prevalence and correlates of breast cancer among women in Eastern China

The purpose was to investigate the prevalence rate, characteristics and related factors of breast cancer among women in Eastern China. A total of 122,058 female subjects completed the study, with 320 confirmed cases of breast cancer (crude prevalence: 262.5/100,000; standardized prevalence: 207.7/100,000). Among all of the identified breast cancer cases, 91.6% were diagnosed after the age of 35 and 60.0% were diagnosed before menopause. The odds ratios (95% confidence interval) of those breast cancer risk factors as selected through multivariate logistic regression were as follows: 5.438 (1.553-19.004) for family history of breast cancer, 3.556 (1.880-6.728) for high behavior intervention score, 3.556 (0.904-13.994) for history of diabetes, 3.357 (1.131-9.969) for history of benign breast tumors, 2.196 (1.355-3.556) for poor overall life satisfaction, 1.826 (0.995-3.350) for premenopause of breast cancer, 1.528 (1.083-2.155) for high BMI index, 1.500 (0.920-2.446) for poor financial status, 1.497 (1.014-2.211) for multiple miscarriages/abortions, and 1.231 (0.972-1.559) for infrequent consumption of garlic (frequent garlic consumption is a protective factor). There were significantly more cases of breast cancer diagnosed prior to menopause than after menopause, and most of the patients were diagnosed after the age of 35. These findings suggest that attention should be focused on the incidence of breast cancer among premenopausal women older than 35.

Effects of ARHI on cell cycle progression and apoptosis levels of breast cancer cells

The purposes of this study were to investigate the role of Aplysia Ras Homolog I (ARHI) on cell growth, proliferation, apoptosis, and other biological characteristics of HER2-positive breast cancer cells. Our goal was to provide experimental evidence for the development of future effective treatments of HER2-positive breast cancer. A pcDNA3.1-ARHI eukaryotic expression vector was constructed and transfected into the human HER2-positive breast cancer cell lines SK-BR-3 and JIMT-1. Then, various experimental methods were utilized to analyze the biological characteristics of ARHI-expressing breast cancer cells and to examine the impact of expression of the ARHI gene on cyclin D1, p27(Kip1), and calpain1 expression. We further analyzed the cells in each group after treatment with trastuzumab to examine the effects of this drug on various cellular characteristics. When we compared pcDNA3.1-ARHI-expressing SK-BR-3 and JIMT-1 cells to their respective empty vector and control groups, we found that cell viability was significantly lower (p < 0.05) in the ARHI-expressing cells, and the proportions of G1 phase cells and apoptotic cells were significantly higher in the ARHI-expressing cells (p < 0.05). In all groups of SK-BR-3 cells, trastuzumab treatment significantly decreased cell growth (p < 0.05). The proportion of cells in G1 phase and the number of apoptotic cells in the pcDNA3.1-ARHI-expressing group were significantly higher than that in the empty vector group and the control group (p < 0.05). The growth of pcDNA3.1-ARHI-transfected JIMT-1 cells was significantly decreased (p < 0.05), while the proportion of apoptotic cells was significantly increased (p < 0.05). Cell growth, viability, and the percentage of apoptotic cells were similar between the JIMT-1 empty vector and control groups. ARHI expression inhibited cyclin D1 expression in SK-BR-3 cells and JIMT-1 cells, while it promoted p27(Kip1) and calpain1 expression in these cells. ARHI expression inhibits the growth and proliferation of HER2-positive breast cancer cells, while it also promotes apoptosis in these cells. ARHI expression also improves the sensitivity of JIMT-1 cells to trastuzumab by inducing apoptosis.

The effects of RKIP gene expression on the biological characteristics of human triple-negative breast cancer cells in vitro

The purpose of this study was to investigate the effect of Raf kinase inhibitor protein (RKIP) on the growth, proliferation, invasion and metastasis of triple-negative breast cancer (TNBC) cells to provide experimental evidence for developing future therapies against human TNBC. The pcDNA3.1-RKIP eukaryotic expression vector was constructed and transfected into the TNBC cell line MDA-MB-231. The alterations of the biological characteristics of RKIP-transfected MDA-MB-231 cells were analyzed using the following approaches: a growth curve, a 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay, bromodeoxyuridine (BrdU) staining and a cell migration assay. The effects of the RKIP gene on MMP-1 and MMP-2 expression were also examined. The pcDNA3.1 empty vector-transfected and mock-transfected MDA-MB-231 cells were used as control groups. Compared with the empty vector-transfected and mock-transfected cells, the cell growth of RKIP-transfected MDA-MB-231 cells was significantly reduced. The empty vector-transfected group was not significantly different compared with the mock-transfected MDA-MB-231 cells. The results of the MTT and BrdU assays demonstrated that the proliferation of pcDNA3.1-RKIP-transfected cells was significantly reduced compared to the control cells (P < 0.05). The result of the cell migration assay suggested that the cross-membrane migration rate of the pcDNA3.1-RKIP-transfected cells was significantly lower than that of the control MDA-MB-231 cells (P < 0.05). We also demonstrated that RKIP may inhibit MMP-1 and MMP-2 expression in MDA-MB-231 cells. The RKIP gene may play a role in inhibiting cellular proliferation. The RKIP gene may also have some inhibitory effects on the invasiveness and metastatic capability of human TNBC cells.

Dysregulated expression of dicer and drosha in breast cancer

Large-scale profiling approaches have revealed global down-regulation of microRNAs (miRNAs) in several human cancer types including breast cancer. Altered expression of Dicer and Drosha, two key enzymes in the miRNA maturation, is believed to be one of the most important mechanisms. By using quantitative real-time RT-PCR (QT-PCR), we examined the expression of Dicer and Drosha in 49 pairs of matched human breast cancer tissues. Decreased expression was observed in 53.1% (Dicer), 51.9% (Drosha) and 75.5% (Dicer plus Drosha) breast cancer tissues. In conclusion, the decreased expression of Dicer and Drosha may play a role in down-regulation of miRNAs in breast cancer.