With the proposition of the cancer stem cell theory, researchers have separated and app-raised cancer stem cells from many malignant tumors such as leukemia, breast cancer, brain tumor, lung cancer, prostatic carcinoma and so on. Some scholars discovered that CD133+ may be a specific marker of the colon cancer,which led the fide of the colon cancer stem cell research. This paper presents the latest progress on colon cancer stern cell through its contribution on clinical drug-resistence, metastasis and application.

AIM: This study is designed to demonstrate the drug resistance breast cancer cell line MCF-7/ADM has a higher proportion of cancer stem cells than its original parent cell line MCF-7 in vitro.METHODS: Firstly,the drug resistance of MCF-7/ADM was estimated by MTT method,and then higher proportion of cancer stem cells in MCF-7/ADM than that in MCF-7 was demonstrated by three aspects: side population analysis,sphere culture and cell surface markers of breast cancer stem cells.RESULTS: The drug resistance index of MCF-7/ADM compared to MCF-7 was 37.1.The proportion of side population in MCF-7/ADM and MCF-7 was 9.60%?0.66% versus 0.39%?0.11%;The proportion of sphere-initiating cells in MCF-7/ADM and MCF-7 was 10.27%?0.64% versus 1.03%?0.15%,and the proportion of CD+44CD-24 cells in these two cell lines was 64.87%?3.87% versus 3.70%?0.53%,all are statistically significant.CONCLUSION: ADM resistance breast cancer cell line MCF-7/ADM has a higher proportion of cancer stem cells than that in its original cell line MCF-7.

MicroRNAS( miRNAs) are a class of single strand, small non-coding RNAs about 22 nucleotides, which have the function to regulate gene expression post-transcriptionally and control the biological processes,such as proliferation, differentiation and apoptosis. Recent studies indicate that miRNA plays an important role in tumor involved in invasion and metastasis. This article mainly reviews the feature of miRNA and its effect in metastasis or recurrence of breast cancer.

Purpose: This study aims to comprehensively evaluate the clinical efficacy of chemotherapy or endocrine therapy maintenance in metastatic breast cancer (MBC) patients. Materials and Methods: The meta-analysis of randomized clinical trials (RCTs) and propensity score matching of multicenter cohort study evaluated MBC patients who underwent first-line chemotherapy or endocrine therapy maintenance. This study is registered with PROSPERO: CRD42017071858 and ClinicalTrials.gov: NCT04258163. Results: A total of 2,867 patients from 15 RCTs and 760 patients from multicenter cohort were included. The results from meta-analysis showed that chemotherapy maintenance improved progression-free survival (PFS) (hazard ratio [HR], 0.63; 95% confidence interval [CI], 0.54 to 0.73; p < 0.001; moderate-quality evidence) and overall survival (OS) (HR, 0.87; 95% CI 0.78 to 0.97; p=0.016; high-quality evidence) than observation. In the cohort study, for hormone receptor–positive MBC patients, chemotherapy maintenance improved PFS (HR, 0.67; 95% CI, 0.52 to 0.85; p < 0.001) and OS (HR, 0.55; 95% CI 0.42 to 0.73; p < 0.001) compared with observation, and endocrine therapy maintenance also improved PFS (HR, 0.65; 95% CI, 0.53 to 0.80; p < 0.001) and OS (HR, 0.55; 95% CI, 0.44 to 0.69; p < 0.001). There were no differences between chemotherapy and endocrine therapy maintenance in PFS and OS (all p > 0.05). Regardless of the continuum or switch maintenance therapy, showed prolonged survival in MBC patients who were response to first-line treatment. Conclusion This study provided evidences for survival benefits of chemotherapy and endocrine therapy maintenance in MBC patients, and there was no difference efficacy between chemotherapy and endocrine therapy maintenance for hormone receptor–positive patients.

Long non-coding RNAs (lncRNAs) play an important role in cancer metastasis. Exploring metastasis-associated lncRNAs and developing effective strategy for targeted regulation of lncRNA function in vivo are of utmost importance for the treatment of metastatic cancer, which however remains a big challenge. Herein, we identified a new functional lncRNA (denoted lncBCMA), which could stabilize the expression of eukaryotic translation elongation factor 1A1 (eEF1A1) via antagonizing its ubiquitination to promote triple-negative breast cancer (TNBC) growth and metastasis. Based on this regulatory mechanism, an endosomal pH-responsive nanoparticle (NP) platform was engineered for systemic lncBCMA siRNA (siBCMA) delivery. This NPs-mediated siBCMA delivery could effectively silence lncBCMA expression and promote eEF1A1 ubiquitination, thereby leading to a significant inhibition of TNBC tumor growth and metastasis. These findings show that lncBCMA could be used as a potential biomarker to predict the prognosis of TNBC patients and NPs-mediated lncBCMA silencing could be an effective strategy for metastatic TNBC treatment.