scholarly journals PAPOLA contributes to Cyclin D1 mRNA alternative polyadenylation and promotes breast cancer cells proliferation

2021 ◽  
pp. jcs.252304
Author(s):  
Chrysoula Komini ◽  
Irini Theohari ◽  
Andromachi Lambrianidou ◽  
Lydia Nakopoulou ◽  
Theoni Trangas

Poly(A) polymerases add the poly(A) tail at the 3’ end of nearly all eukaryotic mRNA, are associated with proliferation and cancer. To elucidate the role of the most studied mammalian poly(A) polymerase α (PAPOLA) in cancer, we assessed its expression in 221 breast cancer samples and found it to correlate strongly with the aggressive triple-negative subtype. Silencing PAPOLA in MCF-7 and MDA-MB-231 breast cancer cells reduced proliferation and anchorage-independent growth by decreasing steady-state CCND1 mRNA and protein levels. Whereas the length of the CCND1 mRNA poly(A) tail was not affected, its 3' untranslated region (3'UTR) lengthened. Overexpressing PAPOLA caused CCND1 mRNA 3'UTR shortening with a concomitant increase in the corresponding transcript and protein, resulting in growth arrest in MCF-7 cells and DNA damage in HEK-293 cells, whereas in the P53 mutant MDA-MB-231 promoted proliferation.Our data suggest PAPOLA as a possible candidate target for the control of tumor growth, mostly relevant to triple-negative tumors, a group characterized by its overexpression and lacking alternative targeted therapies.

2021 ◽  
Vol 14 ◽  
Author(s):  
Bayan Al-Momany ◽  
Hana Hammad ◽  
Mamoun Ahram

Background: Androgens potentially have an important role in the biology of breast cancer, particularly triple-negative breast cancer (TNBC). Androgen receptor (AR) may offer a novel therapeutic strategy including the use of microRNA (miRNA) molecules. We have previously shown that AR agonist, dihydrotestosterone (DHT), increases the expression of miR-328-3p in the TNBC MDA-MB-231 cells. One target of the latter miRNA is ATP-binding cassette subfamily G member 2 (ABCG2), which modulates the chemo-response of cancer cells by pumping out xenobiotics. Objective: Using MDA-MB-231 cells as a model system for TNBC, we hypothesized that DHT would induce cell sensitivity towards doxorubicin via increasing levels of miR-328-3p and, consequently, reducing ABCG2 levels. Methods: Chemo-response of cells towards doxorubicin, tamoxifen, and mitoxantrone was evaluated using cell viability MTT assay. Cells were transfected with both miR-328-3p mimic or antisense molecules. Real-time PCR was utilized to assess RNA levels and immunoblotting was performed to investigate levels of ABCG2 protein. PCR arrays were used to assess changes in the expression of drug response regulatory genes. Results: Contrary to our hypothesis, treating MDA-MB-231 cells with DHT, no effect towards tamoxifen or mitoxantrone and increased cell resistance towards doxorubicin were noted, concomitant with decreased expression of ABCG2. This under-expression of ABCG2 was also found in MCF-7 and MDA-MB-453 cells treated with DHT. Although miR-328-3p decreased ABCG2 mRNA and protein levels, the miRNA did not alter the chemo-response of cells towards doxorubicin and did not affect DHT-induced chemo-resistance. AR activation slightly decreased the expression of 5 genes, including insulin-like growth factor 1 receptor, that may explain the mechanism of DHT-induced chemo-resistance of cells. Conclusion: DHT regulates chemo-response via a mechanism independent of ABCG2 and miR-328-3p.


1995 ◽  
Vol 14 (3) ◽  
pp. 391-394 ◽  
Author(s):  
S Y James ◽  
A G Mackay ◽  
K W Colston

ABSTRACT The effects of the novel vitamin D analogue, EB1089 alone, or in combination with the retinoid, 9-cis retinoic acid (9-cis RA) on indices of apoptosis in MCF-7 breast cancer cells have been examined. EB1089 was capable of reducing bcl-2 protein, a suppressor of apoptosis, and increasing p53 protein levels in MCF-7 cell cultures following 96h treatment. In the presence of 9-cis RA, EB1089 acted to further enhance the down-regulation and up-regulation of bcl-2 and p53 respectively. Furthermore, EB1089 induces DNA fragmentation in MCF-7 cells, a key feature of apoptosis, alone and in combination with 9-cis RA in situ. The observation that EB1089 and 9-cis RA act in a cooperative manner to enhance induction of apoptosis in these cells may have therapeutic implications.


2020 ◽  
Vol 44 (26) ◽  
pp. 11137-11147 ◽  
Author(s):  
Bharvi Sharma ◽  
Liang Gu ◽  
Ruvesh Pascal Pillay ◽  
Nosipho Cele ◽  
Paul Awolade ◽  
...  

A series of 1H-1,2,3 triazole grafted tetrahydro-β-carboline-chalcone/ferrocenylchalcone conjugates were synthesized and in vitro evaluated against estrogen responsive (MCF-7) and triple negative (MDA-MB-231) breast cancer cells.


2020 ◽  
Vol 21 (20) ◽  
pp. 7802 ◽  
Author(s):  
Vincenzo Quagliariello ◽  
Michelino De Laurentiis ◽  
Stefania Cocco ◽  
Giuseppina Rea ◽  
Annamaria Bonelli ◽  
...  

Hyperglycemia, obesity and metabolic syndrome are negative prognostic factors in breast cancer patients. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, achieving unprecedented efficacy in multiple malignancies. However, ICIs are associated with immune-related adverse events involving cardiotoxicity. We aimed to study if hyperglycemia could affect ipilimumab-induced anticancer efficacy and enhance its cardiotoxicity. Human cardiomyocytes and estrogen-responsive and triple-negative breast cancer cells (MCF-7 and MDA-MB-231 cell lines) were exposed to ipilimumab under high glucose (25 mM); low glucose (5.5 mM); high glucose and co-administration of SGLT-2 inhibitor (empagliflozin); shifting from high glucose to low glucose. Study of cell viability and the expression of new putative biomarkers of cardiotoxicity and resistance to ICIs (NLRP3, MyD88, cytokines) were quantified through ELISA (Cayman Chemical) methods. Hyperglycemia during treatment with ipilimumab increased cardiotoxicity and reduced mortality of breast cancer cells in a manner that is sensitive to NLRP3. Notably, treatment with ipilimumab and empagliflozin under high glucose or shifting from high glucose to low glucose reduced significantly the magnitude of the effects, increasing responsiveness to ipilimumab and reducing cardiotoxicity. To our knowledge, this is the first evidence that hyperglycemia exacerbates ipilimumab-induced cardiotoxicity and decreases its anticancer efficacy in MCF-7 and MDA-MB-231 cells. This study sets the stage for further tests on other breast cancer cell lines and primary cardiomyocytes and for preclinical trials in mice aimed to decrease glucose through nutritional interventions or administration of gliflozines during treatment with ipilimumab.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dan Qiu ◽  
Xianxin Yan ◽  
Xinqin Xiao ◽  
Guijuan Zhang ◽  
Yanqiu Wang ◽  
...  

Abstract Background The precancerous disease of breast cancer is an inevitable stage in the tumorigenesis and development of breast neoplasms. Quercetin (Que) has shown great potential in breast cancer treatment by inhibiting cell proliferation and regulating T cell function. γδ T cells are a class of nontraditional T cells that have long attracted attention due to their potential in immunotherapy. In this study, we revealed the immunomodulatory function of Que through regulation of the JAK/STAT1 signaling pathway, which was followed by the synergistic killing of breast cancer cells. Methods In the experimental design, we first screened target genes with or without Que treatment, and we intersected the Que target with the disease target by functional enrichment analysis. Second, MCF-10A, MCF-10AT, MCF-7 and MDA-MB-231 breast cancer cell lines were treated with Que for 0 h, 24 h and 48 h. Then, we observed the expression of its subsets by coculturing Que and γδ T cells and coculturing Que and γδ T cells with breast tumor cells to investigate their synergistic killing effect on tumor cells. Finally, Western blotting was used to reveal the changes in proteins related to the JAK/STAT1 signaling pathway after Que treatment in MCF-10AT and MCF-7 cells for 48 h. Results The pathway affected by Que treatment was the JAK/STAT1 signaling pathway and was associated with precancerous breast cancer, as shown by network pharmacology analysis. Que induced apoptosis of MCF-10AT, MCF-7 and MDA-MB-231 cells in a time- and concentration-dependent manner (P < 0.05). Most importantly, Que promoted the differentiation of γδ T cells into the Vδ2 T cell subpopulation. The best ratio of effector cells to target cells (E/T) was 10:1, the killing percentages of γδ T cells against MCF-10A, MCF-10AT, MCF-7, and MDA-MB-231 were 61.44 ± 4.70, 55.52 ± 3.10, 53.94 ± 2.74, and 53.28 ± 1.73 (P = 0.114, P = 0.486, and P = 0.343, respectively), and the strongest killing effect on precancerous breast cancer cells and breast cancer cells was found when the Que concentration was 5 μM and the E/T ratio was 10:1 (64.94 ± 3.61, 64.96 ± 5.45, 55.59 ± 5.98, and 59.04 ± 5.67, respectively). In addition, our results showed that Que increased the protein levels of IFNγ-R, p-JAK2 and p-STAT1 while decreasing the protein levels of PD-L1 (P < 0.0001). Conclusions In conclusion, Que plays a synergistic role in killing breast cancer cells and promoting apoptosis by regulating the expression of IFNγ-R, p-JAK2, p-STAT1 and PD-L1 in the JAK/STAT1 signaling pathway and promoting the regulation of γδ T cells. Que may be a potential drug for the prevention of precancerous breast cancer and adjuvant treatment of breast cancer.


Author(s):  
xiaohong wang ◽  
kai cheng ◽  
guoqiang zhang ◽  
yue yu ◽  
song liu ◽  
...  

Abstract Background: Exosomes have been shown to be associated with chemotherapy resistance transmission between cancer cells. However, the cargo and function of exosomes changed in response to doxorubicin remains unclear. Methods: We compared proteome profiles of exosomes extracted from the supernatant of MCF-7(S/Exo) and MCF-7/ADR(A/Exo) cells. We confirmed the differential expression of the candidate target-exosomic-CD44 by immune gold staining and western blot. We further studied the changes of chemosensitivity and CD44 expression in MCF-7 cells co-incubated with A/Exo. We analyzed the levels of exosomal CD44 from patient plasma, and compared the sensitivity and specificity of exosomic CD44 and plasma CD44 on diagnosis of chemoresistance. We modified the MCF-7-derived exosomes loaded with siRNA against CD44 to observe the effects of targeting reduced CD44 expression in lumimal A breast cancer cells. Results: DOX increased the exosomes release from MCF-7/ADR cells and the exosomes mediated proteins intercellular transfer in breast cancer chemoresistance regulation. The candidate target of CD44 in A/Exo was much higher than in S/Exo and the increase levels of exosomic CD44 (21.65-fold) was much higher than cellular CD44 (6.55-fold). The same results were obtained in clinical samples. Exosome-siRNA targeted CD44 (Exos-siCD44) could efficiently targeted to silence its expression. When co-cultured on Exos-siCD44, breast cancer cells exhibited reduced cell proliferation and enhanced susceptibility to DOX and the same phenomenon was observed in mice. Conclusion:Drug-resistant breast cancer cells spread resistance capacity to sensitive ones by releasing exosomes to transfer proteins in intercellular.


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