Identification of Claudins by Western Blot and Immunofluorescence in Different Cell Lines and Tissues

Author(s):  
Lorenza González-Mariscal ◽  
Erika Garay ◽  
Miguel Quirós
Keyword(s):  
2020 ◽  
Vol 20 (23) ◽  
pp. 2070-2079
Author(s):  
Srimadhavi Ravi ◽  
Sugata Barui ◽  
Sivapriya Kirubakaran ◽  
Parul Duhan ◽  
Kaushik Bhowmik

Background: The importance of inhibiting the kinases of the DDR pathway for radiosensitizing cancer cells is well established. Cancer cells exploit these kinases for their survival, which leads to the development of resistance towards DNA damaging therapeutics. Objective: In this article, the focus is on targeting the key mediator of the DDR pathway, the ATM kinase. A new set of quinoline-3-carboxamides, as potential inhibitors of ATM, is reported. Methods: Quinoline-3-carboxamide derivatives were synthesized and cytotoxicity assay was performed to analyze the effect of molecules on different cancer cell lines like HCT116, MDA-MB-468, and MDA-MB-231. Results: Three of the synthesized compounds showed promising cytotoxicity towards a selected set of cancer cell lines. Western Blot analysis was also performed by pre-treating the cells with quercetin, a known ATM upregulator, by causing DNA double-strand breaks. SAR studies suggested the importance of the electron-donating nature of the R group for the molecule to be toxic. Finally, Western-Blot analysis confirmed the down-regulation of ATM in the cells. Additionally, the PTEN negative cell line, MDA-MB-468, was more sensitive towards the compounds in comparison with the PTEN positive cell line, MDA-MB-231. Cytotoxicity studies against 293T cells showed that the compounds were at least three times less toxic when compared with HCT116. Conclusion: In conclusion, these experiments will lay the groundwork for the evolution of potent and selective ATM inhibitors for the radio- and chemo-sensitization of cancer cells.


2020 ◽  
Vol 19 ◽  
pp. 153303382098078
Author(s):  
Yanjuan Guo ◽  
Nannan Zhao ◽  
Jianli Zhou ◽  
Jianxin Dong ◽  
Xing Wang

Objective: The present study aimed to explore the function of sirtuin 2 (SIRT2) on cell proliferation, apoptosis, rat sarcoma virus (RAS)/ extracellular signal-regulated kinase (ERK) pathway in endometrial cancer (EC). Methods: SIRT2 expression in human EC cell lines and human endometrial (uterine) epithelial cell (HEEC) line was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. SIRT2 knock-down and control knock-down plasmids were transfected into HEC1A cells, respectively; SIRT2 overexpression and control overexpression plasmids were transfected into Ishikawa cells, respectively. After transfection, SIRT2, HRas proto-oncogene, GTPase (HRAS) expressions were evaluated by RT-qPCR and western blot. ERK and phosphorylated ERK (pERK) expressions were evaluated by western blot. Meanwhile, cell proliferation and cell apoptosis were measured. Results: Compared to normal HEEC cell line, SIRT2 mRNA and protein expressions were increased in most human EC cell lines (including HEC1A, RL952 and AN3CA), while were similar in Ishikawa cell line. In HEC1A cells, SIRT2 knock-down decreased cell proliferation but increased apoptosis. In Ishikawa cells, SIRT2 overexpression induced cell proliferation but inhibited apoptosis. For RAS/ERK pathway, SIRT2 knock-down reduced HRAS and inactivated pERK in HEC1A cells, whereas SIRT2 overexpression increased HRAS and activated pERK in Ishikawa cells, suggesting that SIRT2 was implicated in the regulation of RAS/ERK pathway in EC cells. Conclusion: SIRT2 contributes to the EC tumorigenesis, which appears as a potential therapeutic target.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Qi ◽  
Wenping Yang ◽  
Shuang Liu ◽  
Fanjie Han ◽  
Haibin Wang ◽  
...  

Abstract Background Lung cancer is one of the important health threats worldwide, of which 5-year survival rate is less than 15%. Non-small-cell lung cancer (NSCLC) accounts for about 80% of all lung cancer with high metastasis and mortality. Methods Cisplatin loaded multiwalled carbon nanotubes (Pt-MWNTS) were synthesized and used to evaluate the anticancer effect in our study. The NSCLC cell lines A549 (cisplatin sensitive) and A549/DDP (cisplatin resistant) were used in our in vitro assays. MTT was used to determine Cancer cells viability and invasion were measured by MTT assay and Transwell assay, respectively. Apoptosis and epithelial-mesenchymal transition related marker proteins were measured by western blot. The in vivo anti-cancer effect of Pt-MWNTs were performed in male BALB/c nude mice (4-week old). Results Pt-MWNTS were synthesized and characterized by X-ray diffraction, Raman, FT-IR spectroscopy and scan electron microscopy. No significant cytotoxicity of MWNTS was detected in both A549/DDP and A549 cell lines. However, Pt-MWNTS showed a stronger inhibition effect on cell growth than free cisplatin, especially on A549/DDP. We found Pt-MWNTS showed higher intracellular accumulation of cisplatin in A549/DDP cells than free cisplatin and resulted in enhanced the percent of apoptotic cells. Western blot showed that application of Pt-MWNTS can significantly upregulate the expression level of Bax, Bim, Bid, Caspase-3 and Caspase-9 while downregulate the expression level of Bcl-2, compared with free cisplatin. Moreover, the expression level of mesenchymal markers like Vimentin and N-cadherin was more efficiently reduced by Pt-MWNTS treatment in A549/DDP cells than free cisplatin. In vivo study in nude mice proved that Pt-MWNTS more effectively inhibited tumorigenesis compared with cisplatin, although both of them had no significant effect on body weight. Conclusion Pt-MWNT reverses the drug resistance in the A549/DDP cell line, underlying its possibility of treating NSCLC with cisplatin resistance.


2021 ◽  
Vol 11 (11) ◽  
pp. 2137-2145
Author(s):  
Xuejuan Zhu ◽  
Danqian Lu

Background: Sulfiredoxin (Srx) has been identified to play important roles in the development of various cancers. However, the precise effects and underlying mechanism of Srx on the progression of HCC are far from being fully understood. Materials and Methods: The abundances of Srx in THLE-2 cell and HCC cell lines were determined by western blot and RT-qPCR. Next, SK-Hep-1 cells were transfected with shRNA-Srx or shRNA-NC and treated with TBHQ (an extracellular signal-regulated kinase (ERK) activator) for functional experiments. Then, CCK8 and colony formation assays were used to determine cell proliferation and clone-forming abilities in vitro. Cell migration and invasion were assessed via wound healing and transwell assays. The expression of MMP2, MMP9 and key members in ERK/nuclear factor E2 related factor (Nrf2) signaling pathway was detected by performing western blot analysis. Results: We reported evidence that Srx was frequently up-regulated in HCC cell lines. Srx interference constrained cell proliferation, colony formation rate, migration and invasion of SK-Hep-1 cells. Moreover, mechanistic investigations indicated that Srx interference significantly inhibited the activation of ERK/Nrf2 signaling pathway, and ERK activator TBHQ can reverse the functions of Srx interference in SK-Hep-1 cells. Conclusion: Overall, Downregulation of Srx might impede HCC progression by suppressing ERK/Nrf2 signaling pathway. Findings in the current study reported the functional involvement and molecular mechanism of Srx in HCC, suggesting that Srx might have a potential therapeutic value in HCC treatment.


2015 ◽  
Vol 69 (6) ◽  
pp. 497-504 ◽  
Author(s):  
Zhengzuo Sheng ◽  
Yang Liu ◽  
Caipeng Qin ◽  
Zhenhua Liu ◽  
Yeqing Yuan ◽  
...  

OBJECTIVE:To investigate if IgG can be expressed in clear cell renal cell carcinoma (cRCC) , and the expression of IgG is involved in the cancer progression. If IgG expression can serve as a potential target in cancer therapies and be used for judging the prognosis.MATERIALS AND METHODS:By immunohistochemistry, we detected IgG in cRCC tissues(75 cRCC tissues and75 adjacent normal kidney tissues). Immunofluorescence and Western blot was used to detect the IgG in cRCC cell lines (786-0, ACHN and CAKI-I). By RT-PCR, the functional transcript of IgG heavy chain was detected. Knockdown of IgG was to analyze the proliferation, migration and invasion ability by CCK8, Transwell and Matrigel and apoptosis in cRCC cell lines.RESULTS:By immunohistochemistry, we found strong staining of IgG in 66 cases of 75 cRCC tissues and 63 cases of 75 adjacent normal kidney tissues. Immunofluorescence and Western blot was found IgG in cRCC cell lines. Knock-down IgG in cRCC cell lines resulted in significant inhibition of cell proliferation, migration and invasion, and the induction of apoptosis of the 786-0 cells. The immunohistochemistry analysis showed that high IgG expression significantly correlated with the poor differentiation and advanced stage of cRCC.CONCLUSION:IgG was over expressed in cRCC and was involved in the proliferation, migration and invasion of cancer cells. IgG expression may serve as a potential target in cancer therapies and could be used for judging the prognosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fanguo Kong ◽  
Yansheng Shang ◽  
Xingyuan Diao ◽  
Jiaguo Huang ◽  
Hui Liu

Objective. Esophageal carcinoma (ESCA) is a common malignant gastrointestinal tumor. The abnormal expression of NOLC1 is involved in the tumorigenesis of various human tumors, whereas the function and mechanism of NOLC1 in ESCA remain unclear. In this study, we explored the relationship between NOLC1 and poor prognosis of ESCA, and its role and mechanism in the occurrence of ESCA. Methods. The NOLC1 expression in ESCA tissues and cell lines was determined by qRT-PCR, immunohistochemistry, or western blot. The Kaplan–Meier method was conducted to estimate the overall survival. Cox regression analysis was carried out to examine the association between patient characteristics and prognosis. A recombined lentiviral vector containing NOLC1 was applied for transfecting ESCA cells (Eca109 and TE-13) and established a stable cell line with low NOLC1 expression or high NOLC1 expression, in the absence or presence of PI3K inhibitor (LY294002) treatment. Cell proliferation, apoptosis rate, invasion ability, migration ability, and PI3K/AKT pathway were detected by CCK8 assay, flow cytometry, Transwell assay, wound-healing assay, and western blot. Results. NOLC1 overexpression was observed in ESCA tissues and ESCA cell lines (EC9706, Eca109, TE-13, Kyse170, T.TN) compared with adjacent normal tissues and normal esophageal cell line HEEC. NOLC1 overexpression was markedly associated with bigger tumor size, lymph node metastasis, and advanced TNM stage. Patients with NOLC1 overexpression have shorter overall survival than that of those with low NOLC1 expression. NOLC1 overexpression was considered to be an independent poor prognostic factor affecting overall survival. NOLC1 knockdown inhibited proliferation, migration, invasion, and cyclin B1 expression and promoted the apoptosis and cleaved-caspase-3 expression of Eca109 and TE-13 cells. NOLC1 overexpression accelerated proliferation, migration, invasion, and cyclin B1 expression and inhibited the apoptosis and cleaved-caspase-3 expression of ESCA cells via activating PI3K/AKT pathway. Rescue experiments showed that PI3K inhibitor (LY294002) could reverse the phenomenon caused by NOLC1 overexpression. Conclusion. NOLC1 may be a marker for poor prognosis. It can participate in the occurrence and development of ESCA via the PI3K/AKT pathway.


2021 ◽  
Author(s):  
Wangyang zheng ◽  
Yuling Zheng ◽  
Xue Bai ◽  
Yongxu Zhou ◽  
Liang Yu ◽  
...  

Abstract Background: Ribophorin family (RPNs) are important regulatory subunits of the proteasome. By influencing Ubiquitin-proteasome system activity, RPNs are responsible for almost all processes of physiology and pathology of mammalian cells. Nevertheless, little is known about the role of RPNs in HCC.Methods: In this work, using the online databases Oncomine, UCSC, Kaplan-Meier Plotter, UALCAN, cBioPortal, TIMER2, GeneMANIA,and STRING, we first evaluated the expression, diagnostic, prognostic, genetic alteration, immunity, gene network, and functional enrichment of RPNs in HCC. QPCR and western blot were used to detect RPN6 and RPN9 expressions in HCC tissues and cell lines. Then we performed studies to eveulated their functions in HCC cells proliferation, migration, and invasion in vitro. Results: All RPNs were surprisingly consistently upregulated in HCC tissues. Moreover, RPNs expression pattern is correlated with HCC tumor grade. RPN2, RPN3, RPN6, RPN9, RPN10, RPN11, and RPN12 have robust values in HCC diagnose. Then, survival analysis revealed that high expression of RPN1, RPN2, RPN4, RPN5, RPN6, RPN9, and RPN11were correlated with unfavorable HCC overall survival. Functional enrichment for RPNs, indicated that RPNs have many potential biosynthesis activities expert for UPS functions. Western blot, and qRT-PCR further verified these results in HCC tissues and cell lines. The silencing of RPN6 and RPN9 significantly influenced HCC cells' proliferation, migration, and invasion in vitro.Conclusions: RPN families functions as an important oncogene in HCC. RPN6 and RPN9 have the potential to be potential biomarkers and targets for HCC.


2020 ◽  
Author(s):  
Lijuan Zhang ◽  
Meng Tian ◽  
Jiamao Lin ◽  
Jianbo Zhang ◽  
Haiyong Wang ◽  
...  

Abstract Background: Estrogen receptor β (ERβ) can regulate cellular signaling through non-genomic mechanisms, potentially promoting resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, the mechanisms underlying the ERβ-mediated resistance to EGFR TKIs remain poorly understood. Methods: qRT-PCR was performed to investigate ERβ1 and ERβ5 expression levels in cell lines. The localization of ERβ and ERβ1 within cells was assessed using immunocytochemistry and immunofluorescence. The effect of estradiol and/or gefitinib on EGFR signaling pathways was determined by western blot. Cell viability and colony formation assays were used to assess gefitinib response for different cell lines. The apoptosis was verified by tunel and western blot. Immunohistochemistry was used to assess the expression of ERβ1 in lung adenocarcinoma tissues. Patient survival was estimated using the Kaplan-Meier method, and comparisons between groups were conducted using log-rank tests. Results: PC9 cell lines stably overexpressing ERβ1 or ERβ1/ERβ5 were established successfully. Immunofluorescence revealed that ERβ5 overexpression partly retained ERβ1 in the cytoplasm. Immunoblotting analyses revealed that EGFR pathway activation levels were higher in PC9/ERβ1/5 cells than those in PC9/ERβ1 or control PC9 cells. In the presence of estradiol, PI3K/AKT/mTOR pathway activation levels were higher in ERβ1/5-expressing cells than those in ERβ1-expressing cells. Additionally, PC9/ERβ1/5 cells were less prone to the cytotoxic and pro-apoptotic effects of gefitinib compared with PC9/ERβ1 or control PC9 cells. Conclusion: Cytoplasmic ERβ1 was associated with poor progression-free survival in lung cancer patients treated with EGFR TKIs. These results suggest that anti-estrogen therapy might reverse EGFR TKI treatment resistance to some extent in selected patients.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246197
Author(s):  
Jorge Marquez ◽  
Jianping Dong ◽  
Chun Dong ◽  
Changsheng Tian ◽  
Ginette Serrero

Antibody-drug conjugates (ADC) are effective antibody-based therapeutics for hematopoietic and lymphoid tumors. However, there is need to identify new targets for ADCs, particularly for solid tumors and cancers with unmet needs. From a hybridoma library developed against cancer cells, we selected the mouse monoclonal antibody 33B7, which was able to bind to, and internalize, cancer cell lines. This antibody was used for identification of the target by immunoprecipitation and mass spectrometric analysis, followed by target validation. After target validation, 33B7 binding and target positivity were tested by flow cytometry and western blot analysis in several cancer cell lines. The ability of 33B7 conjugated to saporin to inhibit in vitro proliferation of PTFRN positive cell lines was investigated, as well as the 33B7 ADC in vivo effect on tumor growth in athymic mice. All flow cytometry and in vitro internalization assays were analyzed for statistical significance using a Welsh’s T-test. Animal studies were analyzed using Two-Way Analysis of Variance (ANOVA) utilizing post-hoc Bonferroni analysis, and/or Mixed Effects analysis. The 33B7 cell surface target was identified as Prostaglandin F2 Receptor Negative Regulator (PTGFRN), a transmembrane protein in the Tetraspanin family. This target was confirmed by showing that PTGFRN-expressing cells bound and internalized 33B7, compared to PTGFRN negative cells. Cells able to bind 33B7 were PTGFRN-positive by Western blot analysis. In vitro treatment PTGFRN-positive cancer cell lines with the 33B7-saporin ADC inhibited their proliferation in a dose-dependent fashion. 33B7 conjugated to saporin was also able to block tumor growth in vivo in mouse xenografts when compared to a control ADC. These findings show that screening antibody libraries for internalizing antibodies in cancer cell lines is a good approach to identify new cancer targets for ADC development. These results suggest PTGFRN is a possible therapeutic target via antibody-based approach for certain cancers.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhidong Zhao ◽  
Xianju Qin

Abstract Colon adenocarcinoma (COAD) is the most common type of gastrointestinal cancer and is still the third leading cause of cancer-related mortality worldwide. Therefore, finding new and promising drugs to eradicate cancer may be a feasible method to treat COAD patients. Cys2-His2 zinc finger proteins (ZFPs) is one of the largest transcription factor family and many of them are highly involved in regulation of cell differentiation, proliferation, apoptosis, and neoplastic transformation. In this study, we identified a tumor-inhibiting factor, ZNF549, which expressed lowly in COAD tissues and COAD cell lines (HT29, HCT116, SW480, LoVo, and SW620). Overexpression of ZNF549 inhibit the ability of COAD cell proliferation and migration. On the contrary, decreasing the ZNF549 expression level promote the ability of COAD cell proliferation and migration. Through bioinformatics analysis, we found that ZNF549 was a potential target of hsa-miR-708-5p (miR-708-5p). Furthermore, we verified the possibility of miR-708-5p targeting the ZNF549 gene, and miR-708-5p inhibited the expression of ZNF549 by luciferase reporter assays, qRT-PCR and western blot assays. Moreover, the relationship between miR-708-5p and phosphatidylinositol 3-kinase/AKt (PI3K/AKt) signal pathway was elucidated. Overexpression and inhibition of miR-708-5p resulted in increased and decreased expression of p-AKt and p-PI3K in HCT116 cells, respectively. RT-qPCR and western blot assays results demonstrated that miR-708-5p regulated COAD cells development by promoting the process of Epithelial-mesenchymal transition (EMT) through PI3K/AKt signaling pathway. In summary, our findings demonstrated that ZNF549, the target gene of miR-708-5p, functions as a tumor suppressor to inhibit COAD cell lines proliferation and migration through regulate the PI3K/AKt signal pathway.


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