scholarly journals HSP90 Inhibitor, 17-DMAG, Alone and in Combination with Lapatinib Attenuates Acquired Lapatinib-Resistance in ER-positive, HER2-Overexpressing Breast Cancer Cell Line

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2630
Author(s):  
Hye Jin Lee ◽  
Seungho Shin ◽  
Jinho Kang ◽  
Ki-Cheol Han ◽  
Yeul Hong Kim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Protein Expression ◽  
Cell Line ◽  
Cell Lines ◽  
Xenograft Model ◽  
Resistant Cell ◽  
Bt474 Cell ◽  
Hsp90 Inhibitors ◽  
Her2 Breast Cancer

Lapatinib, a Human Epidermal growth factor Receptor 2 (HER2)-targeting therapy in HER2-overexpressing breast cancer, has been widely used clinically, but the prognosis is still poor because most patients acquire resistance. Therefore, we investigated mechanisms related to lapatinib resistance to evaluate new therapeutic targets that may overcome resistance. Lapatinib-resistant cell lines were established using SKBR3 and BT474 cells. We evaluated cell viability and cell signal changes, gene expression and protein changes. In the xenograft mouse model, anti-tumor effects were evaluated using drugs. Analysis of the protein interaction network in two resistant cell lines with different lapatinib resistance mechanisms showed that HSP90 protein was commonly increased. When Heat Shock Protein 90 (HSP90) inhibitors were administered alone to both resistant cell lines, cell proliferation and protein expression were effectively inhibited. However, inhibition of cell proliferation and protein expression with a combination of lapatinib and HSP90 inhibitors showed a more synergistic effect in the LR-BT474 cell line than the LR-SKBR3 cell line, and the same result was exhibited with the xenograft model. These results suggest that HSP90 inhibitors in patients with lapatinib-resistant Estrogen Receptor (ER) (+) HER2 (+) breast cancer are promising therapeutics for future clinical trials.

Patterns of HER-family receptor dimerization in trastuzumab susceptible and trastuzumab resistant cell lines

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2533-2533
Author(s):  
R. Dua ◽  
P. Nhonthachit ◽  
C. Rinehart ◽  
C. L. Arteaga ◽  
R. Nahta ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Line ◽  
Cell Lines ◽  
Resistant Cell ◽  
Receptor Expression ◽  
Skbr3 Cell ◽  
Bt474 Cell ◽  
Her2 Overexpression ◽  
Trastuzumab Resistance ◽  
Her Family

2533 Background: HER2 overexpression is associated with accelerated disease progression and poor prognosis in breast cancer. Trastuzumab, a monoclonal antibody targeting the extracellular domain of HER2, is effective in the treatment of metastatic breast cancer. However, most patients treated with trastuzumab eventually develop clinical resistance. To investigate the role of HER-family receptors in trastuzumab resistance, we measured HER-family receptor expression, dimerization, and phosphorylation in trastuzumab susceptible and resistant cell lines. Methods: Cell lysates from trastuzumab susceptible and resistant BT474 and SKBR3 cell lines were obtained from the Arteaga and Esteva laboratories. Proximity-based, multiplexed assays were used to detect and quantify HER1, HER2, and HER3 expression and phosphorylation levels, as well as HER1/HER1, HER1/HER2, HER1/HER3, HER2/HER2, and HER2/HER3 dimers. Samples were incubated with a mixture of HER specific antibodies conjugated either with fluorescent reporter tags (eTags), or biotin, which binds a reporter tag releasing agent (chemical scissor). Reporter molecules are released based on proximity to the scissor in a photochemical reaction and separated by capillary gel electrophoresis. Results: In comparison to trastuzumab susceptible parental cell lines, both SKBR3 and BT474 trastuzumab-resistant cell lines displayed upregulated HER1 expression. Resistant BT474 cell lines exhibited markedly increased levels of HER1/HER2 heterodimers. Increases in HER2 phosphorylation in the trastuzumab resistant SKBR3 cell line were observed, consistent with previous studies implicating trastuzumab in the induction of HER2 phosphorylation. Total HER2 and HER3 levels were similar in trastuzumab susceptible and resistant BT474 cell lines. Conclusions: The development of trastuzumab resistance in these cell line models correlated with HER1 expression and the appearance of HER1:HER2 dimers. Since signaling initiated by such heterodimers is ineffectively antagonized by trastuzumab, these data suggest that selection for proliferative signaling mediated by HER1:HER2 dimers may represent a mechanism of trastuzumab resistance in breast cancer. No significant financial relationships to disclose.

scholarly journals Integrative analysis of mRNA and miRNA profiles identifies miR-193 and miR-210 as potential regulatory biomarkers in different molecular subtypes of breast cancer

2020 ◽  
Author(s):  
Adriane Feijo Evangelista ◽  
Renato J Oliveira ◽  
Viviane A O Silva ◽  
Rene A D C Vieira ◽  
Rui M Reis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cell Line ◽  
Cell Lines ◽  
Breast Cancer Cell ◽  
Cancer Progression ◽  
Triple Negative ◽  
Molecular Subtypes ◽  
Breast Cancer Cell Lines ◽  
Mcf 7

Abstract Introduction: Breast cancer is the most frequently diagnosed malignancy among women. However, the role of microRNA expression in breast cancer progression is not fully understood. In this study we examined predictive interactions between differentially expressed miRNAs and mRNAs in breast cancer cell lines representative of the common molecular subtypes. Integrative bioinformatics analysis identified miR-193 and miR-210 as potential regulatory biomarkers of mRNA in breast cancer. Several recent studies have investigated these miRNAs in a broad range of tumors, but the mechanism of their involvement in cancer progression has not previously been investigated. Methods: The miRNA-mRNA interactions in breast cancer cell lines were identified by parallel expression analysis and miRNA target prediction programs. The expression profiles of mRNA and miRNAs from luminal (MCF-7, MCF-7/AZ and T47D), HER2 (BT20 and SK-BR3) and triple negative subtypes (Hs578T e MDA-MB-231) could be clearly separated by unsupervised analysis using HB4A cell line as a control. Breast cancer miRNA data from TCGA patients were grouped according to molecular subtypes and then used to validate these findings. Expression of miR-193 and miR-210 was investigated by miRNA transient silencing assays using the MCF7, BT20 and MDA-MB-231 cell lines. Functional studies included, xCELLigence system, ApoTox-Glo triplex, flow cytometry and transwell assays were performed to determine cell proliferation, cytotoxicity, apoptosis, migration and invasion, respectively. Results: The most evident effects were associated with cell proliferation after miR-210 silencing in triple negative subtype cell line MDA-MB-231. Using in silico prediction algorithms, TNFRSF10 was identified as one of the potential downstream targets for both miRNAs. The TNFRSF10C and TNFRSF10D mRNA expression inversely correlated with the expression levels of miR-193 and miR210 in breast cell lines and breast cancer patients, respectively. Other potential regulated genes whose expression also inversely correlated with both miRNAs were CCND1, a mediator on invasion and metastasis, and the tumor suppressor gene RUNX3. Conclusion: In summary, our findings identify miR-193 and miR-210 as potential regulatory miRNA in different molecular subtypes of breast cancer and suggest that miR-210 may have specific role in MDA-MB-231 proliferation. Our results highlight important new downstream regulated targets that may serve as promising therapeutic pathways for aggressive breast cancers.

scholarly journals Integrative analysis of mRNA and miRNA profiles identifies miR-193 and miR-210 as potential regulatory biomarkers in different molecular subtypes of breast cancer

2021 ◽  
Author(s):  
Adriane Feijo Evangelista ◽  
Renato J Oliveira ◽  
Viviane A O Silva ◽  
Rene A D C Vieira ◽  
Rui M Reis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cell Line ◽  
Cell Lines ◽  
Breast Cancer Cell ◽  
Cancer Progression ◽  
Triple Negative ◽  
Molecular Subtypes ◽  
Breast Cancer Cell Lines ◽  
Mcf 7

Abstract Background: Breast cancer is the most frequently diagnosed malignancy among women. However, the role of microRNA (miRNA) expression in breast cancer progression is not fully understood. In this study we examined predictive interactions between differentially expressed miRNAs and mRNAs in breast cancer cell lines representative of the common molecular subtypes. Integrative bioinformatics analysis identified miR-193 and miR-210 as potential regulatory biomarkers of mRNA in breast cancer. Several recent studies have investigated these miRNAs in a broad range of tumors, but the mechanism of their involvement in cancer progression has not previously been investigated.Methods: The miRNA-mRNA interactions in breast cancer cell lines were identified by parallel expression analysis and miRNA target prediction programs. The expression profiles of mRNA and miRNAs from luminal (MCF-7, MCF-7/AZ and T47D), HER2 (BT20 and SK-BR3) and triple negative subtypes (Hs578T e MDA-MB-231) could be clearly separated by unsupervised analysis using HB4A cell line as a control. Breast cancer miRNA data from TCGA patients were grouped according to molecular subtypes and then used to validate these findings. Expression of miR-193 and miR-210 was investigated by miRNA transient silencing assays using the MCF7, BT20 and MDA-MB-231 cell lines. Functional studies included, xCELLigence system, ApoTox-Glo triplex assay, flow cytometry and transwell inserts were performed to determine cell proliferation, cytotoxicity, apoptosis, migration and invasion, respectively.Results: The most evident effects were associated with cell proliferation after miR-210 silencing in triple negative subtype cell line MDA-MB-231. Using in silico prediction algorithms, TNFRSF10 was identified as one of the potential regulated downstream targets for both miRNAs. The TNFRSF10C and TNFRSF10D mRNA expression inversely correlated with the expression levels of miR-193 and miR210 in breast cell lines and breast cancer patients, respectively. Other potential regulated genes whose expression also inversely correlated with both miRNAs were CCND1, a known mediator on invasion and metastasis, and the tumor suppressor gene RUNX3.Conclusions: In summary, our findings identify miR-193 and miR-210 as potential regulatory miRNA in different molecular subtypes of breast cancer and suggest that miR-210 may have a specific role in MDA-MB-231 proliferation. Our results highlight important new downstream regulated targets that may serve as promising therapeutic pathways for aggressive breast cancers

Efficacy of Ponatinib Against ABL Tyrosine Kinase Inhibitor Resistant Leukemia Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4413-4413
Author(s):  
Seiichi Okabe ◽  
Tetsuzo Tauchi ◽  
Kazuma Ohyashiki
Keyword(s):  
Cell Proliferation ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Cell Line ◽  
Cell Lines ◽  
Kinase Inhibitor ◽  
Resistant Cell ◽  
Point Mutant ◽  
Abl Tyrosine Kinase ◽  
Abl Tyrosine Kinase Inhibitor

Abstract Abstract 4413 Dasatinib (Sprycel®) and nilotinib (Tasigna®) have each shown superior efficacy as front line treatment for patients with chronic myeloid leukemia (CML)-chronic phase (CP) in comparison with imatinib. Dasatinib and nilotinib are also used for the treatment of CML patients resistant or intolerant to imatinib therapy. However, a substantial number of patients are acquired resistance to nilotinib or dasatinib, the management of CML following the development of ABL tyrosine kinase inhibitor (TKI) resistance remains a challenge. Ponatinib, also known as AP24534, is an oral, the multi-targeted TKI. Ponatinib is currently being investigated in a pivotal phase 2 clinical trial (PACE trial) in patients with resistant or intolerant CML and Philadelphia positive acute lymphoblastic leukemia (Ph+ ALL). However, the molecular and functional consequences of ponatinib against ABL TKI resistant cells are not fully known. In this study, we investigated the ponatinib efficacy by using the BCR-ABL positive cell line, K562 and ABL TKI resistant (K562 imatinib resistant (K562IR), K562 nilotinib resistant (K562NR), K562 dasatinib resistant (K562DR) cells and murine Ba/F3 cell line which was transfected BCR-ABL random mutation, and established the new imatinib and nilotinib resistant Ba/F3 BCR-ABL point mutant (E334V) cells. We first examined the cell proliferation by using resistant cell lines. The proliferation of K562IR and K562 NR and K562DR did not decrease after imatinib (10 μM) or nilotinib (2 μM) or dasatinib (1 μM) treatment compared with parental cell line, K562. The BCR-ABL kinase domain mutation was not found. Point mutant Ba/F3 cell (E334V) was also highly resistant to imatinib (IC50: 15μM) and nilotinib (IC50: 7.5μM). We next examined the intracellular signaling by using these cell lines. Phosphorylation of BCR-ABL and Crk-L was not decreased by ABL TKIs in K562IR, K562NR and Ba/F3 BCR-ABL point mutant cells (E334V). We found the one of src family kinase, Lyn was activated in K562IR and K562NR cells. Co-treatment src kinase inhibitor, PP2 and imatinib or nilotinib significantly reduced the cell proliferation of K562IR and K562NR cells. We also found the phosphorylation of Lyn was reduced and poly (ADP-ribose) polymerase (PARP) was activated. We next examined the efficacy of ponatinib against imatinib and nilotinib resistant cell lines. 72 hours treatment of ponatinib exhibits cell growth inhibition against K562 (IC50: 0.02nM), K562IR (IC50: 15nM), and K562NR (IC50: 3.5nM) cells. We also found the phosphorylation of BCR-ABL, Lyn and Crk-L was reduced and PARP was activated after ponatinib treatment. We next examined the imatinib and nilotinib resistant Ba/F3 cells with point mutant (E334V). We found the cell proliferation was significantly decreased after ponatinib treatment (IC50: 3nM). We also found the phosphorylation of BCR-ABL, Crk-L was reduced and PARP was activated after ponatinib treatment. We next investigated the ponatinib activity against dasatinib resistant cells. We found K562DR cells were highly resistant to ponatinib. IC50 was 400nM. These results suggest that the expression and protein activation signatures identified in this study provide insight into the mechanism of resistance to ABL TKIs. We also demonstrate ponatinib has anti-leukemia effect by reducing ABL and Lyn kinase activity and development of ponatinib resistance and suggests that this information may be of therapeutic relevance. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Downregulation of long non-coding RNA MALAT1 induces tumor progression of human breast cancer through regulating CCND1 expression

2016 ◽  
Vol 11 (1) ◽  
pp. 232-236 ◽  
Author(s):  
Zhang Yang ◽  
Wang Lu ◽  
Li Ning ◽  
Dai Hao ◽  
Sun Jian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Protein Expression ◽  
Cell Lines ◽  
Breast Cancer Cell ◽  
Colony Formation ◽  
Breast Cancer Cell Lines ◽  
Non Coding Rna ◽  
Mrna And Protein Expression ◽  
Long Non Coding Rna

AbstractObjectiveMetastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is already known to be involved in the development and progression of many types of tumors. In the present study, we set to seek the role of MALAT1and the molecular mechanisms in breast cancer.MethodsMALAT1 mRNA expression level was measured by real-time PCR in selected tissues and breast cancer cell lines. SiRNAs targeting MALAT1 were employed to knockdown the endogenous MALAT1. Then cell counting method and colony formation method were applied to reveal the proliferation changes after MALAT1 was suppressed. Afterwards, the mRNA and protein expression of growth related gene cyclinD1 (CCND1) were detected by RT-PCR and western blotting, respectively.ResultsWe found a downregulation of MALAT1 expression in breast cancer cell lines and tissues. Inhibition of its expression led to enhanced cell proliferation and colony formation. Importantly, the mRNA and protein expression of CCND1 was significantly increased in MALAT1-depleted cells.ConclusionMALAT1 is a potential tumor suppressive long non-coding RNA that negatively regulates cell proliferation in breast cancer progression, via suppressing CCND1 expression.

scholarly journals MicroRNA-124 (MiR-124) Inhibits Cell Proliferation, Metastasis and Invasion in Colorectal Cancer by Downregulating Rho-Associated Protein Kinase 1(ROCK1)

2016 ◽  
Vol 38 (5) ◽  
pp. 1785-1795 ◽  
Author(s):  
Liqing Zhou ◽  
Ziran Xu ◽  
Xiaoqiang Ren ◽  
Kaixuan Chen ◽  
Shiyong Xin
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Protein Kinase ◽  
Protein Expression ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Qrt Pcr ◽  
Normal Controls ◽  
In Cells

Background/Aims: MiR-124 inhibits neoplastic transformation, cell proliferation, and metastasis and downregulates Rho-associated protein kinase (ROCK1) in Colorectal Cancer (CRC). The aim of this study was to further investigate the roles and interactions of ROCK1 and miR-124 and the effects of knockdown of ROCK1and MiR-124 in human Colorectal Cancer (CRC). Methods: Three Colorectal cancer cell lines (HCT116, HT29 and SW620) and one Human Colonic Mucosa Epithelial cell line (NCM460) were studied. The protein expression of ROCK1 was examined by Western-blot and qRT-PCR were performed to examine the expression levels of ROCK1 mRNA and miR-124. Furthermore, We performed transfection of cancer cell line (SW620) with pre-miR-124(mimics), anti-miR-124(inhibitor), ROCK1 siRNA and the control, then observed the affects of ROCK1 protein expression by westen-blot, cell proliferation by EDU (5-ethynyl-2'deoxyuridine assay) and expression levels of ROCK1mRNA by qRT-PCR . A soft agar formation assay, Migration and invasion assays were used to determine the effect of regulation of miR-124 and ROCK1, and survivin on the transformation and invasion capability of colorectal cancer cell. Results: MiR-124 expression was significantly downregulated in CRC cell lines compare to normal (P < 0.05). In contrast, ROCK1 protein expression was significantly increased in CRC cell lines compared to the normal (P < 0.05), whereas the gene (ROCK1mRNA) expression remained unaltered (P > 0.05). ROCK1 mRNA was unaltered in cells transfected with miR-124 mimic and miR-124 inhibitor, compared to normal controls. There was a significant reduction in ROCK1 protein in cells transfected with miR-124 mimic and a significant increase in cells transfected with miR-124 inhibitor (P < 0.05). Cell proliferation, transformation and invasion of cells transfected with miR-124 inhibitor were significantly increased compared to those in normal controls (P<0.05). However, cell proliferation, transformation and invasion of cells transfected with ROCK1 siRNA were significantly decreased compared to control (P < 0.05). Conclusions: In conclusion, our results demonstrated that miR-124 not only promoted cancer cell hyperplasia and significantly associated with CRC metastasis and progression, but also downregulated ROCK1 protein expression. More importantly, increased ROCK1 expression or inhibited miR-124 expression may constitute effective new therapeutic strategies for the treatment of renal cancer in the future.

scholarly journals Integrated analysis of mRNA and miRNA profiles revealed the role of miR-193 and miR-210 as potential regulatory biomarkers in different molecular subtypes of breast cancer

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Adriane F. Evangelista ◽  
Renato J. Oliveira ◽  
Viviane A. O. Silva ◽  
Rene A. D. C. Vieira ◽  
Rui M. Reis ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Progression ◽  
Triple Negative ◽  
Molecular Subtypes ◽  
Breast Cancer Cell Lines ◽  
Mcf 7

Abstract Background Breast cancer is the most frequently diagnosed malignancy among women. However, the role of microRNA (miRNA) expression in breast cancer progression is not fully understood. In this study we examined predictive interactions between differentially expressed miRNAs and mRNAs in breast cancer cell lines representative of the common molecular subtypes. Integrative bioinformatics analysis identified miR-193 and miR-210 as potential regulatory biomarkers of mRNA in breast cancer. Several recent studies have investigated these miRNAs in a broad range of tumors, but the mechanism of their involvement in cancer progression has not previously been investigated. Methods The miRNA-mRNA interactions in breast cancer cell lines were identified by parallel expression analysis and miRNA target prediction programs. The expression profiles of mRNA and miRNAs from luminal (MCF-7, MCF-7/AZ and T47D), HER2 (BT20 and SK-BR3) and triple negative subtypes (Hs578T e MDA-MB-231) could be clearly separated by unsupervised analysis using HB4A cell line as a control. Breast cancer miRNA data from TCGA patients were grouped according to molecular subtypes and then used to validate these findings. Expression of miR-193 and miR-210 was investigated by miRNA transient silencing assays using the MCF7, BT20 and MDA-MB-231 cell lines. Functional studies included, xCELLigence system, ApoTox-Glo triplex assay, flow cytometry and transwell inserts were performed to determine cell proliferation, cytotoxicity, apoptosis, migration and invasion, respectively. Results The most evident effects were associated with cell proliferation after miR-210 silencing in triple negative subtype cell line MDA-MB-231. Using in silico prediction algorithms, TNFRSF10 was identified as one of the potential regulated downstream targets for both miRNAs. The TNFRSF10C and TNFRSF10D mRNA expression inversely correlated with the expression levels of miR-193 and miR210 in breast cell lines and breast cancer patients, respectively. Other potential regulated genes whose expression also inversely correlated with both miRNAs were CCND1, a known mediator on invasion and metastasis, and the tumor suppressor gene RUNX3. Conclusions In summary, our findings identify miR-193 and miR-210 as potential regulatory miRNA in different molecular subtypes of breast cancer and suggest that miR-210 may have a specific role in MDA-MB-231 proliferation. Our results highlight important new downstream regulated targets that may serve as promising therapeutic pathways for aggressive breast cancers

Expression of reprogramming factors in breast cancer cell lines and the regulation by activated Stat3

2012 ◽  
Vol 10 (2) ◽  
Author(s):  
Chul Min Yang ◽  
Tomohiro Chiba ◽  
Bernd Groner
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Protein Expression ◽  
Cell Line ◽  
Cell Lines ◽  
Breast Cancer Cell ◽  
Breast Cancer Cell Lines ◽  
Epigenetic Alterations ◽  
Reprogramming Factors ◽  
Mcf 7

AbstractDistinct gene expression patterns, accompanied by particular epigenetic states, provide the basis for different stages of cellular differentiation. The programming of cells usually proceeds from stem cells to progenitor cells to differentiated progeny. The process, however, is not irreversible, and pluripotency can be reestablished in terminally differentiated cells through the expression of the reprogramming factors (RFs) octamer-binding transcription factor 3/4 (Oct4), sex-determining region Y box 2 (Sox2), Krüppel-like factor 4 (Klf4), and c-Myc. Tumor cell formation is characterized by partial differentiation, epigenetic alterations, and drastic changes in the transcriptional program. As the RF can cause pluripotency through cellular dedifferentiation and epigenetic alterations, it is possible that the activation of their genes might contribute to cellular transformation. The shared capacity for self-renewal between pluripotent stem cells and cancer stem cells is in line with this assumption. The deregulation of RF has been observed in poorly differentiated, high-grade breast cancer and is associated with unfavorable prognosis. Signal transducer and activator of transcription 3 (Stat3) mediates a wide variety of cellular functions including survival, proliferation, and differentiation and is constitutively activated in tumor cells of diverse origins. Stat3 is also accelerates somatic cell reprogramming. We investigated the connection between Stat3 activation and the expression of RF in the breast cancer cell lines MCF-7, SK-BR-3, MDA-MB-231, and MDA-MB-468 and the normal mammary epithelial cell line MCF-10A by real-time quantitative PCR and immunoblot analyses. We detected strong expression of Sox2 and Klf4 messenger RNA (mRNA) in MCF-7 cells and the expression of Oct4 mRNA in all the four cell lines. Immunoblot analyses revealed the strong protein expression of homeobox protein Nanog (Nanog), Oct4, and Sox2 in MCF-7 cells. This cell line only contains a low level of phosphorylated Stat3. We also examined the effect of the Stat3 inhibitor Stattic on the expression of RF and observed that it suppressed mRNA and protein expression of RF in MCF-7 cells. The expression levels of reprogramming proteins can strongly differ from their mRNA expression levels and do not necessarily correspond with the extent of Stat3 activation in the cell lines compared.

scholarly journals Pyrotinib Sensitizes 5-Fluorouracil-Resistant HER2+ Breast Cancer Cells to 5-Fluorouracil

2020 ◽  
Vol 28 (5) ◽  
pp. 519-531
Author(s):  
Jianing Yi ◽  
Shuai Chen ◽  
Pingyong Yi ◽  
Jinlin Luo ◽  
Meng Fang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Expression ◽  
Cancer Cells ◽  
Cell Lines ◽  
Breast Cancer Cells ◽  
Kinase Inhibitor ◽  
Parental Cell ◽  
Expression Levels ◽  
Her2 Breast Cancer

5-Fluorouracil (5-FU) is a widely used chemotherapeutic agent for breast cancer. However, acquired chemoresistance leads to a loss of its efficacy; methods to reverse are urgently needed. Some studies have shown that pyrotinib, an ErbB receptor tyrosine kinase inhibitor, is effective against HER2+ breast cancer. However, whether pyrotinib sensitizes 5-FU-resistant breast cancer cells to 5-FU is unknown. We hypothesized that the combination of pyrotinib and 5-FU would show synergistic antitumor activity, and pyrotinib could reverse 5-FU resistance in HER2+ breast cancer cells in vitro and in vivo. Our data showed that pyrotinib inhibited the growth of 5-FU-resistant SKBR-3/FU and MDA-MB-453/FU cell lines and the parental cell lines. 5-FU remarkably suppressed the growth of SKBR-3 and MAD-MB-453 cells. However, SKBR-3/FU and MAD-MB-453/FU cells showed resistance to 5-FU. A combination of pyrotinib and 5-FU resulted in the synergistic inhibition of the growth of the 5-FU-resistant SKBR-3/FU and MDA-MB-453/FU cell lines and the parental cell lines. Pyrotinib decreased significantly the IC50 values of 5-FU and the thymidylate synthase (TS) mRNA expression levels in the 5-FU-resistant SKBR-3/FU and MDA-MB-453/FU cell lines and the parental cell lines and increased significantly the intracellular concentration of 5-FU in SKBR-3/FU and MDA-MB-453/FU cells. In addition, pyrotinib reduced the ABCG2 mRNA and protein expression levels in SKBR-3/FU and MDA-MB-453/FU cells and downregulated the protein expression levels of pAKT, pHER2, and pHER4 in all four cell lines. After TS or ABCG2 in 5-FU-resistant breast cancer cells was knocked down, the sensitivity of SKBR-3/FU and MDA-MB-453/FU cells to 5-FU was restored. Moreover, in vivo experiments demonstrated that pyrotinib in combination with 5-FU more effectively inhibited SKBR-3/FU tumor growth than either pyrotinib or 5-FU alone. In conclusion, our findings suggest that pyrotinib could restore sensitivity of 5-FU-resistant HER2+ breast cancer cells to 5-FU through downregulating the expression levels of TS and ABCG2.

scholarly journals Gpn3 Is Essential for Cell Proliferation of Breast Cancer Cells Independent of Their Malignancy Degree

2019 ◽  
Vol 18 ◽  
pp. 153303381987082 ◽  
Author(s):  
Bárbara Lara-Chacón ◽  
Sandra L. Guerrero-Rodríguez ◽  
Karla J. Ramírez-Hernández ◽  
Angélica Yamilett Robledo-Rivera ◽  
Marco Antonio Velasco Velazquez ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cellular Models ◽  
Her2 Breast Cancer ◽  
Public Data

Successful therapies for patients with breast cancer often lose their initial effectiveness. Thus, identifying new molecular targets is a constant goal in the fight against breast cancer. Gpn3 is a protein required for RNA polymerase II nuclear targeting in both yeast and human cells. We investigated here the effect of suppressing Gpn3 expression on cell proliferation in a progression series of isogenic cell lines derived from the nontumorigenic MCF-10A breast cells that recapitulate different stages of breast carcinogenesis. Gpn3 protein levels were comparable in all malignant derivatives of the nontumorigenic MCF-10A cells. shRNA-mediated inhibition of Gpn3 expression markedly decreased cell proliferation in all MCF-10A sublines. A fraction of the largest RNA polymerase II subunit Rpb1 was retained in the cytoplasm, but most Rpb1 remained nuclear after suppressing Gpn3 in all cell lines studied. Long-term proliferation experiments in cells with suppressed Gpn3 expression resulted in the eventual loss of all isogenic cell lines but MCF-10CA1d.cl1. In MCF-10CA1d.cl1 cells, Gpn3 knockdown reduced the proliferation of breast cancer stem cells as evaluated by mammosphere assays. After the identification that Gpn3 plays a key role in cell proliferation in mammary epithelial cells independent of the degree of transformation, we also analyzed the importance of Gpn3 in other human breast cancer cell lines from different subtypes. Gpn3 was also required for cell proliferation and nuclear translocation of RNA polymerase II in such cellular models. Altogether, our results show that Gpn3 is essential for breast cancer cell proliferation regardless of the transformation level, indicating that Gpn3 could be considered a molecular target for the development of new antiproliferative therapies. Importantly, our analysis of public data revealed that Gpn3 overexpression was associated with a significant decrease in overall survival in patients with estrogen receptor-positive and Human epidermal growth factor receptor 2 (HER2+) breast cancer, supporting our proposal that targeting Gpn3 could potentially benefit patients with breast cancer.

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