MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.     

miR-34c-3p与M2型肿瘤相关巨噬细胞在三阴性乳腺癌中的表达及意义

目的:检测miR-34c-3p与M2型肿瘤相关巨噬细胞（tumor-associated macrophage,TAM)在三阴性乳腺癌(triple negative breast cancer,TNBC)中的表达，并探讨其在乳腺癌发病中的意义。方法:选择2017年2月至2018年1月于西京医院就诊的68例TNBC患者作为实验组(A组)，以同期就诊的70例乳腺纤维腺瘤患者作为对照组(B组)。采用Real-time RT-PCR 检测组织标本中miR-34c-3p的表达；流式细胞检测M2型TAM的表达；ELISA法检测血清中IL-10的表达。并进一步分析miR-34c-3p的表达与乳腺癌M2型TAM及血清IL-10水平的相关性。结果:A、B组miR-34c-3p的相对表达量分别为0.84±0.08、1.29±0.71，A组明显低于B组，差异有统计学意义(P<0.05)。与B组比较，A组M2型TAM(CD68+CD163+)细胞比例显著升高(P<0.05)。A组血清IL-10的表达［(19.69±4.93) pg/ml］较B组［(17.26±3.51) pg/ml］显著升高，差异有统计学意义(P<0.05)。TNBC组织中miR-34c-3p的表达与M2型TAM比例及血清IL-10表达均呈显著负相关(r=-0.508，r=-0.656，P<0.05)。结论:TNBC组织中miR-34c-3p的表达下调，M2型TAM比例及血清IL-10表达均显著升高，促进TNBC进展。     

The co-expression characteristics of LAG3 and PD-1 on the T cells of patients with breast cancer reveal a new therapeutic strategy

Many studies have shown a special interaction between LAG3 and PD-1 in T cell inhibition, while the co-expression and effect of LAG3 and PD-1 on T cells in breast cancer patients are still not very clear. Here, with strict exclusion criteria, 88 patients with breast cancer and 18 healthy controls were enrolled. The percentages of LAG3⁺PD-1⁺ T cells in their peripheral blood (PBL) and tumor infiltrating T cells (TIL) were analyzed by flow cytometry, which showed an increase in TILs but no difference in PBLs and presented differences in TILs in different molecular subtypes (P < 0.05). In triple-negative breast cancer (TNBC), the highest percentages were observed, while in ER+/PR+ breast cancer, the lowest percentages were observed; however, these percentages were not different in different clinical stages (P > 0.05). Immunohistochemical staining showed that the expression of their ligands, PD-L1, MHC class II molecular and FGL1, was inconsistent in different molecular subtypes and clinical stages. Analysis of the functions of T cells with different phenotypes showed that the proliferation and secretion capacity of LAG3⁺PD-1⁺ T cells was obviously exhausted, with more than a two-fold of decrease compared with the groups of single positive LAG3 or PD-1 (P < 0.05). Finally, in a mouse model of TNBC, the dual blockade of LAG3 and PD-1 was indicated to achieve a better anti-tumour effect than either one alone (P < 0.05), which may provide a new strategy for the immunoregulatory treatment of patients with TNBC in the future.     

Therapeutic cooperation between auranofin,a thioredoxin reductase inhibitor and anti-PD-L1 antibody for treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBCs) is a very aggressive and lethal form of breast cancer with no effective targeted therapy. Neoadjuvant chemotherapies and radiotherapy remains a mainstay of treatment with only 25–30% of TNBC patients responding. Thus, there is an unmet clinical need to develop novel therapeutic strategies for TNBCs. TNBC cells have increased intracellular oxidative stress and suppressed glutathione, a major antioxidant system, but still, are protected against higher oxidative stress. We screened a panel of antioxidant genes using the TCGA and METABRIC databases and found that expression of the thioredoxin pathway genes is significantly upregulated in TNBC patients compared to non-TNBC patients and is correlated with adverse survival outcomes. Treatment with auranofin (AF), an FDA-approved thioredoxin reductase inhibitor caused specific cell death and impaired the growth of TNBC cells grown as spheroids. Furthermore, AF treatment exerted a significant in vivo antitumor activity in multiple TNBC models including the syngeneic 4T1.2 model, MDA-MB-231 xenograft and patient-derived tumor xenograft by inhibiting thioredoxin redox activity. We, for the first time, showed that AF increased CD8^+Ve T-cell tumor infiltration in vivo and upregulated immune checkpoint PD-L1 expression in an ERK1/2-MYC-dependent manner. Moreover, combination of AF with anti-PD-L1 antibody synergistically impaired the growth of 4T1.2 primary tumors. Our data provide a novel therapeutic strategy using AF in combination with anti-PD-L1 antibody that warrants further clinical investigation for TNBC patients.     

Sacituzumab govitecan: breakthrough targeted therapy for triple-negative breast cancer

Introduction: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with an increased risk of recurrence and cancer-related death. Unlike hormone receptor-positive or HER2-positive breast cancers, there are limited targeted therapies available to treat TNBC and cytotoxic chemotherapy remains the mainstay of treatment. Sacituzumab govitecan (IMMU-132) is an antibody-drug conjugate targeting Trop-2 expressing cells and selectively delivering SN-38, an active metabolite of irinotecan.

Areas covered: This review covers the mechanism of action, safety and efficacy of sacituzumab govitecan in patients with previously treated, metastatic TNBC. Additionally, efficacy data in other epithelial malignancies is included based on a PubMed search for ‘sacituzumab govitecan’ and ‘clinical trial’.

Expert opinion: Sacituzumab govitecan has promising anti-cancer activity in patients with metastatic TNBC previously treated with at least two prior lines of systemic therapy based on a single arm Phase I/II clinical trial. A confirmatory Phase III randomized clinical trial is ongoing. Sacituzumab govitecan has a manageable side effect profile, with the most common adverse events being nausea, neutropenia, and diarrhea. The activity of sacituzumab govitecan likely extends beyond TNBC with promising early efficacy data in many other epithelial cancers, including hormone receptor-positive breast cancer.     

Outcomes of non-metastatic triple negative breast cancers: Real-world data from a large Indian cohort

BackgroundTriple negative Breast tumor (TNBC) is an aggressive tumor with sparse data worldwide.MethodsWe analyzed non-metastatic TNBC from 2013 to 2019 for demographics, practice patterns, and survival by the Kaplan Meir method. Prognostic factors for OS and DFS were evaluated using Cox Proportional Hazard model estimator for univariate and multivariable analysis after checking for collinearity among the variables.ResultsThere were 1297 patients with median age of 38 years; 41 (33.3%) among 123 tested were BRCA-positives. Among these 593 (45.7%) had stage III disease, 1279 (98.6%) were grade III, 165 (13.0%) had peri-nodal extension (PNE), 212 (16.0%) lympho-vascular invasion (LVI), and 21 (1.6%) were metaplastic; 1256 (96.8%) received chemotherapy including 820 (63.2%) neoadjuvant with 306 (40.0%) pCR. Grade ≥3 toxicities occurred in 155 (12.4%) including two deaths and 3 s-primaries. 1234 (95.2%) underwent surgery [722 (55.7%) breast conservations] and 1034 (79.7%) received radiotherapy.At a median follow-up of 54 months, median disease-free (DFS) was 92.2 months and overall survival (OS) was not reached. 5-year estimated DFS and OS was 65.9% and 80.3%. There were 259 (20.0%) failures; predominantly distant (204, 15.7%) - lung (51%), liver (31.8%).In multivariate analysis presence of LVI (HR-2.00, p-0.003), PNE (HR-2.09 p-0.003), older age (HR-1.03, p-0.002) and stage III disease (HR-4.89, p-0.027), were associated with poor OS.ConclusionRelatively large contemporary data of non-metastatic TNBC confirms aggressive biology and predominant advanced stage presentation which adversely affects outcomes. The data strongly indicate the unmet need for early detection to optimize care.     

新疆多民族地区三阴性乳腺癌BRCA1基因突变分析

目的：研究新疆多民族地区三阴性乳腺癌( TNBC ) BRCA1基因的突变情况及突变者与未突变者临床、病理组织特征的差异。方法以新疆多民族地区130例TNBC患者为研究对象,从静脉血提取基因组DNA,采用PCR联合直接测序法检测BRCA1基因突变情况。结果130例TNBC患者BRCA1突变率为17．7%(23/130),其中汉族与少数民族 TNBC 患者 BRCA1突变率分别为20．5%(17/83)、12．8%(6/47),差异无统计学意义(χ2=1．856,P=0．869)。130例TNBC患者中发现23例BRCA1突变的19个位点,其中8个为新发现的位点;4个BRCA1基因突变“热点”;此外还发现了9例(6．9%,9/130)致病性突变,5例无义突变,4例移码突变。早发性 TNBC 组 BRCA1突变率28．3%(13/46)高于晚发性TNBC组11．9%(10/84),差异有统计学意义(χ2=5．460,P<0．05)。 BRCA1基因突变组与BRCA1基因未突变组相比,发病年龄早,腋窝淋巴结转移率高, TNM分期晚,差异均有统计学意义( P<0．05)。结论新疆多民族地区TNBC患者BRCA1基因突变率高;突变者与未突变者相比,存在临床病理组织差异。     

Overexpression of IL-8 promotes cell migration via PI3K-Akt signaling pathway and EMT in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a type of malignant and heterogeneous tumor in premenopausal females with ineffective therapeutic targets. IL-8 is one of the earliest discovered chemotaxis cytokines which expression is closely related to the progress of various cancers. Previous studies showed that IL-8 determines the prognosis of TNBC patients, nevertheless how IL-8 influences the progress of TNBC is unclear. In our studies, we discovered that overexpression of IL-8 promotes TNBC cells (TNBCs) migration and tumor growth via the PI3K-Akt and MAPK signaling pathway. Cell-cycle of TNBCs arrest at S phase by overexpression of IL-8, however, there is no significant variation on the cell viability and cell apoptosis of TNBCs. Besides, overexpression of IL-8 result in the downregulation of E-cadherin and the upregulation of Cyclin B1 in MDA-MB-231 cells. Taken together, our results suggest that IL-8 performs a crucial role in the progress of TNBC, and it could be a novel therapeutic target of TNBC.     

Pivarubicin Is More Effective Than Doxorubicin Against Triple-Negative Breast Cancer In Vivo

Triple-negative breast cancer (TNBC) is unresponsive to antiestrogen and anti-HER2 therapies, requiring the use of cytotoxic drug combinations of anthracyclines, taxanes, cyclophosphamide, and platinum compounds. Multidrug therapies achieve pathological cure rates of only 20–40%, a consequence of drug resistance and cumulative dose limitations necessitated by the reversible cardiotoxic effects of drug therapy. Safer and more effective treatments for TNBC are required to achieve durable therapeutic responses. This study describes the mechanistic analyses of the novel anthracycline, pivarubicin, and its in vivo efficacy against human primary TNBC. Pivarubicin directly activates PKCd, triggers rapid mitochondrial-dependent apoptosis, and circumvents resistance conferred by overexpression of P-glycoprotein, Bcl-2, Bcl-X_L, and Bcr-Abl. As a consequence, pivarubicin is more cytotoxic than doxorubicin against MDA-MB-231, and SUM159 TNBC cell lines grown in both monolayer culture and tumorspheres. Comparative in vivo efficacy of pivarubicin and doxorubicin was performed in an orthotopic NSG mouse model implanted with MDA-MB-231 human TNBC cells and treated with the maximum tolerated doses (MTDs) of pivarubicin and doxorubicin. Tumor growth was monitored by digital caliper measurements and determination of endpoint tumor weight and volume. Endpoint cardiotoxicity was assessed histologically by identifying microvacuolization in ventricular cardiomyocytes. Primary tumors treated with multiple rounds of doxorubicin at MTD failed to inhibit tumor growth compared with vehicletreated tumors. However, administration of a single MTD of pivarubicin produced significant inhibition of tumor growth and tumor regression relative to tumor volume prior to initiation of treatment. Histological analysis of hearts excised from drug- and vehicle-treated mice revealed that pivarubicin produced no evidence of myocardial damage at a therapeutic dose. These results support the development of pivarubicin as a safer and more effective replacement for doxorubicin against TNBC as well as other malignancies for which doxorubicin therapy is indicated.