scholarly journals Pan-cancer analysis reveals synergistic effects of CDK4/6i and PARPi combination treatment in RB-proficient and RB-deficient breast cancer cells

2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Songyu Li ◽  
Yixiang Zhang ◽  
Na Wang ◽  
Rong Guo ◽  
Qiaoling Liu ◽  
...  
2015 ◽  
Vol 33 (28_suppl) ◽  
pp. 135-135
Author(s):  
Ye-Won Jeon ◽  
Youngjin Suh

135 Background: The anti-cancer effects of celecoxib and luteolin are well known. Although our previous study demonstrated that the combination of celecoxib and luteolin synergistically inhibits breast tumor growth compared with each of the treatments alone, we did not uncover the molecular mechanisms of these effects. The aims of our present study were to compare the effects of a celecoxib and luteolin combination treatment in four different human breast cell lines and to determine the mechanisms of action in vitro and in vivo. Methods: Using MCF-7, MCF7/HER18, MDA-MB-231 and SkBr3 human breast cancer cells, proliferation assay, apoptosis assay, inhibition assay with MEK and PI3K inhibitor in addition to western blotting and xenograft study after treatment with celecoxib and luteolin. Results: The synergistic effects of a celecoxib and luteolin combination treatment yielded significantly greater cell growth inhibition in all four breast cancer cell lines compared with the single agents alone. In particular, combined celecoxib and luteolin treatment significantly decreased the growth of MDA-MB-231 cancer cells in vivo compared with either agent alone. The celecoxib and luteolin combination treatment induced synergistic effects via Akt inactivation and extracellular signal-regulated kinase (ERK) signaling inhibition in MCF-7 and MCF7/HER18 cells and via Akt inactivation and ERK signaling activation in MDA-MB-231 and SkBr3 cells. Conclusions: These results demonstrate the synergistic anti-tumor effect of the celecoxib and luteolin combination treatment in different four breast cancer cell lines, thus introducing the possibility of this combination as a new treatment modality.


2019 ◽  
Vol 20 (22) ◽  
pp. 5581
Author(s):  
Chung-Yih Wang ◽  
Chun-Yuan Chang ◽  
Chun-Yu Wang ◽  
Kaili Liu ◽  
Chia-Yun Kang ◽  
...  

Radiation is a widely used therapeutic method for treating breast cancer. N-dihydrogalactochitosan (GC), a biocompatible immunostimulant, is known to enhance the effects of various treatment modalities in different tumor types. However, whether GC can enhance the radiosensitivity of cancer cells remains to be explored. In this study, triple-negative murine 4T1 breast cancer cells transduced with multi-reporter genes were implanted in immunocompetent Balb/C mice to track, dissect, and identify liver-metastatic 4T1 cells. These cells expressed cancer stem cell (CSC) -related characteristics, including the ability to form spheroids, the expression of the CD44 marker, and the increase of protein stability. We then ex vivo investigated the potential effect of GC on the radiosensitivity of the liver-metastatic 4T1 breast cancer cells and compared the results to those of parental 4T1 cells subjected to the same treatment. The cells were irradiated with increased doses of X-rays with or without GC treatment. Colony formation assays were then performed to determine the survival fractions and radiosensitivity of these cells. We found that GC preferably increased the radiosensitivity of liver-metastatic 4T1 breast cancer cells rather than that of the parental cells. Additionally, the single-cell DNA electrophoresis assay (SCDEA) and γ-H2AX foci assay were performed to assess the level of double-stranded DNA breaks (DSBs). Compared to the parental cells, DNA damage was significantly increased in liver-metastatic 4T1 cells after they were treated with GC plus radiation. Further studies on apoptosis showed that this combination treatment increased the sub-G1 population of cells, but not caspase-3 cleavage, in liver-metastatic breast cancer cells. Taken together, the current data suggest that the synergistic effects of GC and irradiation might be used to enhance the efficacy of radiotherapy in treating metastatic tumors.


2019 ◽  
Vol 123 ◽  
pp. 399-411 ◽  
Author(s):  
Mozhgan Jahani ◽  
Mehri Azadbakht ◽  
Hassan Rasouli ◽  
Reza Yarani ◽  
Davood Rezazadeh ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257298
Author(s):  
Joohyun Woo ◽  
Jong Bin Kim ◽  
Taeeun Cho ◽  
Eun Hye Yoo ◽  
Byung-In Moon ◽  
...  

The response rate to treatment with trastuzumab (Tz), a recombinant humanized anti-HER2 monoclonal antibody, is only 12–34% despite demonstrated effectiveness on improving the survival of patients with HER2-positive breast cancers. Selenium has an antitumor effect against cancer cells and can play a cytoprotective role on normal cells. This study investigated the effect of selenium on HER2-positive breast cancer cells and the mechanism in relation to the response of the cells to Tz. HER2-positive breast cancer cell lines, SK-BR-3 as trastuzumab-sensitive cells, and JIMT-1 as Tz-resistant cells were treated with Tz and sodium selenite (selenite). Cell survival rates and expression of Her2, Akt, and autophagy-related proteins, including LC3B and beclin 1, in both cell lines 72 h after treatment were evaluated. Significant cell death was induced at different concentrations of selenite in both cell lines. A combined effect of selenite and Tz at 72 h was similar to or significantly greater than each drug alone. The expression of phosphorylated Akt (p-Akt) was decreased in JIMT-1 after combination treatment compared to that after only Tz treatment, while p-Akt expression was increased in SK-BR-3. The expression of beclin1 increased particularly in JIMT-1 after only Tz treatment and was downregulated by combination treatment. These results showed that combination of Tz and selenite had an antitumor effect in Tz-resistant breast cancer cells through downregulation of phosphorylated Akt and beclin1-related autophagy. Selenite might be a potent drug to treat Tz-resistant breast cancer by several mechanisms.


2020 ◽  
Author(s):  
Jianing Yi ◽  
Pingyong Yi ◽  
Shuai Chen ◽  
Qian Li ◽  
Runzhang Wu ◽  
...  

Abstract BACKGROUND: Clinical trials have shown that pyrotinib+ capecitabine significantly improved efficacy of patients with human epidermal growth factor receptor 2(HER2) +breast cancer. However, whether pyrotinib sensitizes 5‑Fluorouracil(5‑FU)‑resistant breast cancer cells to 5‑FU is unknown. This study aimed to investigate the effects of pyrotinib on HER2+breast cancer cells with resistance to 5‑FU and provide new clues for the pyrotinib treatment in 5-FU-resistant breast cancer.METHODS: the 5‑FU‑resistant breast cancer cell lines SK-BR-3/FU and MAD-MB-453/FU were established by continuous exposure of the parental cells to 5‑FU.The effects of pyrotinib on these cell lines were examined by growth inhibitory activity assay, reverse transcription‑quantitative polymerase chain reaction, Western blot analysis, high-performance liquid chromatography and animal experiments.RESULTS: Pyrotinib inhibited the proliferation of 5-FU-resistant and parental HER2-positive breast cancer cells and re-sensitized resistant cells to 5-FU by decreasing the expression of thymidylate synthase(TS) and ABC transporter subfamily G member 2(ABCG2). In a xenograft model, combination treatment with 5-FU and pyrotinib showed greater antitumor activity than either agent alone. CONCLUSIONS: Our results offer a preclinical rationale for clinical investigations of combination treatment with pyrotinib and 5-FU for 5-FU-resistant HER2-positive breast cancer.


Author(s):  
Fujun Li ◽  
Lixia Miao ◽  
Teng Xue ◽  
Hao Qin ◽  
Santanu Mondal ◽  
...  

Abstract Background Tamoxifen resistance presents a huge clinical challenge for breast cancer patients. An understanding of the mechanisms of tamoxifen resistance can guide development of efficient therapies to prevent drug resistance. Methods We first tested whether peptidylarginine deiminase 2 (PAD2) may be involved in tamoxifen-resistance in breast cancer cells. The effect of depleting or inhibiting PAD2 in tamoxifen-resistant MCF-7 (MCF7/TamR) cells was evaluated both in vitro and in vivo. We then investigated the potential of Cl-amidine, a PAD inhibitor, to be used in combination with tamoxifen or docetaxel, and further explored the mechanism of the synergistic and effective drug regimen of PADs inhibitor and docetaxel on tamoxifen-resistant breast cancer cells. Results We report that PAD2 is dramatically upregulated in tamoxifen-resistant breast cancer. Depletion of PAD2 in MCF7/TamR cells facilitated the sensitivity of MCF7/TamR cells to tamoxifen. Moreover, miRNA-125b-5p negatively regulated PAD2 expression in MCF7/TamR cells, therefore overexpression of miR-125b-5p also increased the cell sensitivity to tamoxifen. Furthermore, inhibiting PAD2 with Cl-amidine not only partially restored the sensitivity of MCF7/TamR cells to tamoxifen, but also more efficiently enhanced the efficacy of docetaxel on MCF7/TamR cells with lower doses of Cl-amidine and docetaxel both in vivo and in vivo. We then showed that combination treatment with Cl-amidine and docetaxel enhanced p53 nuclear accumulation, which synergistically induced cell cycle arrest and apoptosis. Meanwhile, p53 activation in the combination treatment also accelerated autophagy processes by synergistically decreasing the activation of Akt/mTOR signaling, thus enhancing the inhibition of proliferation. Conclusion Our results suggest that PAD2 functions as an important new biomarker for tamoxifen-resistant breast cancers and that inhibiting PAD2 combined with docetaxel may offer a new approach to treatment of tamoxifen-resistant breast cancers.


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