• Molecules and Cells
• /
• v.43 no.4
• /
• pp.384-396
• /
• 2020

Breast cancer is one of the most common life-threatening malignancies and the top cause of cancer deaths in women. Although many conventional therapies exist for its treatment, breast cancer still has many handicaps to overcome. Cancer stem cells (CSCs) are a well-known cause of tumor recurrences due to the ability of CSCs for self-renewal and differentiation into cell subpopulations, similar to stem cells. To fully treat breast cancer, a strategy for the treatment of both cancer cells and CSCs is required. However, current strategies for the eradication of CSCs are non-specific and have low efficacy. Therefore, surface biomarkers to selectively treat CSCs need to be developed. Here, 34 out of 641 surface biomarkers on CSCs were identified by proteomic analysis between the human breast adenocarcinoma cell line MCF-7 and MCF-7-derived CSCs. Among them, carcinoembryonic antigen-related cell adhesion molecules 6 (CEACAM6 or CD66c), a member of the CEA family, was selected as a novel biomarker on the CSC surface. This biomarker was then experimentally validated and evaluated for use as a CSC-specific marker. Its biological effects were assessed by treating breast cancer stem cells (BCSCs) with short hairpin (sh)-RNA under oxidative cellular conditions. This study is the first to evaluate the biological function of CD66c as a novel biomarker on the surface of CSCs. This marker is available as a moiety for use in the development of targeted therapeutic agents against CSCs.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.4
• /
• pp.1823-1829
• /
• 2014

Aims: Much evidence suggests that increased glucose metabolism in tumor cells might contribute to the development of acquired chemoresistance. However, the molecular mechanisms are not fully clear. Therefore, we investigated a possible correlation of mRNA expression of HIF-$1{\alpha}$ and GLUT1 with chemoresistance in acute myeloid leukemia (AML). Methods: Bone marrow samples were obtained from newly diagnosed and relapsed AML (M3 exclusion) cases. RNA interference with short hairpin RNA (shRNA) was used to stably silence GLUT1 or HIF-$1{\alpha}$ gene expression in an AML cell line and HIF-$1{\alpha}$ and GLUT1 mRNA expression was measured by real-time quantitative polymerase chain reaction assay (qPCR). Results: High levels of HIF-$1{\alpha}$ and GLUT1 were associated with poor responsiveness to chemotherapy in AML. Down-regulation of the expression of GLUT1 by RNA interference obviously sensitized drug-resistant HL-60/ADR cells to adriamycin (ADR) in vitro, comparable with RNA interference for the HIF-$1{\alpha}$ gene. Conclusions: Our data revealed that over-expression of HIF-$1{\alpha}$ and GLUT1 might play a role in the chemoresistance of AML. GLUT1 might be a potential target to reverse such drug resistance.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3781-3789
• /
• 2012

Background: Pancreatic cancer is one of the most aggressive tumors with a dismal prognosis. The membrane cytoskeletal crosslinker Ezrin participates in several functions including cell proliferation, adhesion, motility and survival. There is increasing evidence that Ezrin is overexpressed in vast majority of malignant tumors and regulates tumor progression. However, its roles in pancreatic cancer remain elusive. Methods: Three pairs of specific Ezrin siRNAs were designed and synthetized and screened to determine the most efficient one for construction of a hairpin RNA plasmid targeting Ezrin. After transfection into the Panc-1 pancreatic cancer cell line, real-time quantitative PCR and Western blotting were performed to examine the expression of mRNA and protein. The MTT method was applied to examine the proliferation and the drug sensibility to Gemcitabine. Flow cytometry was used to assess the cycle and apoptosis, while capacity for invasion was determined with transwell chambers. Furthermore, we detected phosphorylated-Erk1/2 protein and phosphorylated-Akt protein by Western blotting. Results: Real-time quantitative PCR and Western blotting revealed that Ezrin expression was notably down-regulated at both mRNA and protein levels by RNA interference (P< 0.01). Proliferation was inhibited and drug resistance to gemcitabine was improved (P< 0.05). Flow cytometry showed that the proportion of cells in the G1/G0 phase increased (P< 0.01), and in G2/M and S phases decreased (P< 0.05), with no apparent differences in apoptosis (P> 0.05). The capacity for invasion was markedly reduced (P< 0.01). In addition, down-regulating Ezrin expression had no effect on phosphorylated-Akt protein (P>0.05), but could decrease the level of phosphorylated-Erk1/2 protein (P< 0.05). Conclusions: RNA interference of Ezrin could inhibit its expression in the pancreatic cancer cells line Panc-1, leading to a potent suppression of malignant behavior in vitro. Assessment of potential as a target for pancreatic cancer treatment is clearly warranted.