AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in t...AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative(SUM149PT) and luminal(T47D and Au565) cancer cells and nontransformed MCF10 A were investigated. Reverse phase protein microarray(RPPM) was performed with and without 10 μmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins. RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10 A. In comparison to the other lines,cell growth reduction in SUM149 PT coincided with significant induction of endoplasmic reticulum(ER) stress and autophagy after 24 and 48 h of 10 μmol/L FLX,resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker,cleaved microtubule-associated protein 1 light chain 3,in SUM149 PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently,the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis,growth arrest at the G1 phase,autophagy,and caspase-7-mediated cell death.CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy,resulting in death of aggressive triple negative breast cancer SUM149 PT.展开更多
More than 90% of breast cancer-related deaths are caused by metastasis not primary tumor. To effectively reduce cancer mortality, it is extremely important to predict the risk of, and to intervene in, the critical tra...More than 90% of breast cancer-related deaths are caused by metastasis not primary tumor. To effectively reduce cancer mortality, it is extremely important to predict the risk of, and to intervene in, the critical transition from展开更多
Acidosis,regardless of hypoxia involvement,is recognized as a chronic and harsh tumor microenvironment(TME)that educates malignant cells to thrive and metastasize.Although overwhelming evidence supports an acidic envi...Acidosis,regardless of hypoxia involvement,is recognized as a chronic and harsh tumor microenvironment(TME)that educates malignant cells to thrive and metastasize.Although overwhelming evidence supports an acidic environment as a driver or ubiquitous hallmark of cancer progression,the unrevealed core mechanisms underlying the direct effect of acidification on tumorigenesis have hindered the discovery of novel therapeutic targets and clinical therapy.Here,chemical-induced and transgenic mouse models for colon,liver and lung cancer were established,respectively.miR-7 and TGF-β2 expressions were examined in clinical tissues(n=184).RNA-seq,miRNA-seq,proteomics,biosynthesis analyses and functional studies were performed to validate the mechanisms involved in the acidic TME-induced lung cancer metastasis.Our data show that lung cancer is sensitive to the increased acidification of TME,and acidic TME-induced lung cancer metastasis via inhibition of miR-7-5 p.TGF-β2 is a direct target of miR-7-5 p.The reduced expression of miR-7-5 p subsequently increases the expression of TGF-β2 which enhances the metastatic potential of the lung cancer.Indeed,overexpression of miR-7-5 p reduces the acidic p H-enhanced lung cancer metastasis.Furthermore,the human lung tumor samples also show a reduced miR-7-5 p expression but an elevated level of activated TGF-β2;the expressions of both miR-7-5 p and TGF-β2 are correlated with patients’survival.We are the first to identify the role of the miR-7/TGF-β2 axis in acidic p H-enhanced lung cancer metastasis.Our study not only delineates how acidification directly affects tumorigenesis,but also suggests miR-7 is a novel reliable biomarker for acidic TME and a novel therapeutic target for non-small cell lung cancer(NSCLC)treatment.Our study opens an avenue to explore the p H-sensitive subcellular components as novel therapeutic targets for cancer treatment.展开更多
基金Supported by Susan G.Komen for the Cure Career Catalyst in Disparities Research to Ibarra Drendall C(KG090730)Promise Grant to Yu D(KG091020)National Institute of Health to Seewaldt V(R01CA158668)
文摘AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine(FLX) in representative molecular subtypes of breast cancer.METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative(SUM149PT) and luminal(T47D and Au565) cancer cells and nontransformed MCF10 A were investigated. Reverse phase protein microarray(RPPM) was performed with and without 10 μmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins. RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10 A. In comparison to the other lines,cell growth reduction in SUM149 PT coincided with significant induction of endoplasmic reticulum(ER) stress and autophagy after 24 and 48 h of 10 μmol/L FLX,resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker,cleaved microtubule-associated protein 1 light chain 3,in SUM149 PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently,the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis,growth arrest at the G1 phase,autophagy,and caspase-7-mediated cell death.CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy,resulting in death of aggressive triple negative breast cancer SUM149 PT.
文摘More than 90% of breast cancer-related deaths are caused by metastasis not primary tumor. To effectively reduce cancer mortality, it is extremely important to predict the risk of, and to intervene in, the critical transition from
基金supported by the projects of National Natural Science Foundation of China(81874367 and 82074019)Guangdong Key Laboratory for Translational Cancer research of Chinese Medicine(2018B030322011,China)+3 种基金Natural Science Foundation for Distinguished Young Scholars of Guangdong Province,China(2017A030306033)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(2016,China)Project of Educational Commission of Guangdong Province of China(2016KTSCX012)Pearl River Nova Program of Guangzhou,China(201710010108)。
文摘Acidosis,regardless of hypoxia involvement,is recognized as a chronic and harsh tumor microenvironment(TME)that educates malignant cells to thrive and metastasize.Although overwhelming evidence supports an acidic environment as a driver or ubiquitous hallmark of cancer progression,the unrevealed core mechanisms underlying the direct effect of acidification on tumorigenesis have hindered the discovery of novel therapeutic targets and clinical therapy.Here,chemical-induced and transgenic mouse models for colon,liver and lung cancer were established,respectively.miR-7 and TGF-β2 expressions were examined in clinical tissues(n=184).RNA-seq,miRNA-seq,proteomics,biosynthesis analyses and functional studies were performed to validate the mechanisms involved in the acidic TME-induced lung cancer metastasis.Our data show that lung cancer is sensitive to the increased acidification of TME,and acidic TME-induced lung cancer metastasis via inhibition of miR-7-5 p.TGF-β2 is a direct target of miR-7-5 p.The reduced expression of miR-7-5 p subsequently increases the expression of TGF-β2 which enhances the metastatic potential of the lung cancer.Indeed,overexpression of miR-7-5 p reduces the acidic p H-enhanced lung cancer metastasis.Furthermore,the human lung tumor samples also show a reduced miR-7-5 p expression but an elevated level of activated TGF-β2;the expressions of both miR-7-5 p and TGF-β2 are correlated with patients’survival.We are the first to identify the role of the miR-7/TGF-β2 axis in acidic p H-enhanced lung cancer metastasis.Our study not only delineates how acidification directly affects tumorigenesis,but also suggests miR-7 is a novel reliable biomarker for acidic TME and a novel therapeutic target for non-small cell lung cancer(NSCLC)treatment.Our study opens an avenue to explore the p H-sensitive subcellular components as novel therapeutic targets for cancer treatment.