Supramolecular nanodrug targeting CDK4/6 overcomes BAG1 mediated cisplatin resistance in oral squamous cell carcinoma.

Chemoresistance to cisplatin remains a significant challenge affecting the prognosis of advanced oral squamous cell carcinoma (OSCC). However, the specific biomarkers and underlying mechanisms responsible for cisplatin resistance remain elusive. Through comprehensive bioinformatic analyses, we identified a potential biomarker, BCL2 associated athanogene-1 (BAG1), showing elevated expression in head and neck squamous cell carcinoma (HNSCC). Since OSCC represents the primary pathological type of HNSCC, we investigated BAG1 expression in human tumor tissues and cisplatin resistant OSCC cell lines, revealing that silencing BAG1 induced apoptosis in cisplatin-resistant cells both in vitro and in vivo. This effect led to impaired cell viability of cisplatin resistant OSCC cells and indicated a positive correlation between BAG1 expression and the G1/S transition during cell proliferation. Based on these insights, the administration of a CDK4/6 inhibitor in combination with cisplatin effectively overcame cisplatin resistance in OSCC through the CDK4/6-BAG1 axis. Additionally, to enable simultaneous drug delivery and enhance synergistic antitumor efficacy, we developed a novel supramolecular nanodrug LEE011-FFERGD/CDDP, which was validated in an OSCC orthotopic mouse model. In summary, our study highlights the potential of a combined administration of CDK4/6 inhibitor and cisplatin as a promising therapeutic regimen for treating advanced or cisplatin resistant OSCC.

Expression of pro-apoptotic markers is increased along the osteochondral junction in naturally occurring osteochondrosis.

Osteochondrosis (OC) is a naturally occurring disease of the articular-epiphyseal cartilage and subchondral bone layers, leading to pain and decreased mobility. The objective of this study was to characterize gene and protein expression of apoptotic markers in chondrocytes surrounding cartilage canals and along the osteochondral junction of osteochondrosis (OC)-affected and normal cartilage, using naturally occurring disease in horses. Paraffin-embedded osteochondral samples (6 OC, 8 normal controls) and cDNA from chondrocytes captured with laser capture microdissection (4 OC, 6 normal controls) were obtained from the lateral trochlear ridge of femoropatellar joints in 14 immature horses (1-6 months of age). Equine-specific caspase-3, caspase-8, caspase-10, Fas, Bcl-2, BAG-1, TNFα, cytochrome C, thymosin-ß10, and 18S mRNA expression levels were evaluated by two-step real-time quantitative PCR. Percentage of cell death was determined using the TUNEL method. Protein expression of caspase-10, Fas, cytochrome C, and thymosin-ß10 was determined following immunohistochemistry. Statistical analysis was performed using the Wilcoxon rank sum test or two-sample t-test (p < 0.05). In OC samples, there was significantly increased gene expression of caspase-10, Fas, cytochrome C, and thymosin-ß10 in chondrocytes along the osteochondral junction and increased Fas gene expression in chondrocytes adjacent to cartilage canals, compared to controls. In OC samples, higher matrix Fas and cytochrome C protein expression, lower mitochondrial cytochrome C protein expression, and a trend for higher cytoplasmic caspase-10 protein expression were found. Collectively, these results suggest that both extrinsic and intrinsic apoptotic pathways are activated in OC cartilage. Increased apoptosis of osteochondral junction chondrocytes may play a role in OC, based on increased gene expression of several pro-apoptotic markers in this location.

miR­494­BAG­1 axis is involved in cinobufacini­induced cell proliferation and apoptosis in gastric cancer.

Cinobufacini is widely used in the treatment of advanced cancers. It has been previously reported that microRNA (miR)­494 was upregulated in cinobufacini­treated gastric cancer cells; however, the detailed role of miR­494 in the anti­tumor activity of cinobufacini is unclear. The present study aimed to clarify the function of miR­494 in cinobufacini­induced cell behavior changes. Cell viability and proliferation ability were investigated using a Cell Counting Kit­8 assay. Flow cytometry was performed to investigate the apoptosis rate of gastric cancer (GC) cells. The mRNA expression levels of microRNA (miR)­494 and BCL2 associated athanogene 1 (BAG­1) were investigated using reverse transcription­quantitative polymerase chain reaction, and the protein expression level of BAG­1 was investigated using western blot assays. The results demonstrated that treatment with cinobufacini suppressed proliferation and promoted apoptosis of gastric cancer cells. miR­494 acts as a tumor suppressor gene in gastric cancer. In cinobufacini­treated cells, miR­494 and BAG­1 exhibited opposing expression trends. Furthermore, knockdown of miR­494 in cinobufacini­treated cells upregulated the protein expression level of BAG­1, promoted cell proliferation and inhibited cell apoptosis. In addition, inhibition of BAG­1 using small interfering RNA in cinobufacini­treated cells partially abrogated the effects of miR­494 inhibitor on cell proliferation and apoptosis. Thus, these results suggest that cinobufacini suppresses GC cells proliferation and promotes apoptosis partially through the regulation of miR­494­BAG­1 axis, which may provide a novel insight into the functional mechanism of cinobufacini.

Expressions of bcl-2-associated athanogene 1 and epithelial growth factor receptor gene in triple negative breast cancer / 肿瘤研究与临床

Objective To investigate mRNA expressions of bcl-2-associated athanogene1 (BAG-1), epithelial growth factor receptor(EGFR)in triple negative breast cancer(TNBC). Methods Polymerase chain reaction (PCR) method was used to detect mRNA expression levels of BAG-1 and EGFR in 51 TNBC cases combined with adjacent tissues in Taihe Hospital of Shiyan City from October 2013 to August 2014, and the relationship between gene expression and the clinicopathologic parameters of TNBC patients was analyzed. Results The relative expressions of BAG-1 mRNA and EGFR mRNA were 0.57±0.25,0.61±0.21 respectively in TNBC. The expression level of mRNA in breast cancer (0.19±0.12, t = 5.12) was higher than that in adjacent tissues (0.21±0.11, t = 7.17), and there was no significant difference (P< 0.001). The difference of expressions of BAG-1 mRNA and EGFR mRNA in TNBC patients with different clinical stage or lymph node metastasis were statistically significant (all P< 0.05), but there was no significant difference in mRNA expression level of the patients with different tumor diameter or age (all P > 0.05). Conclusion BAG-1 mRNA, EGFR mRNA are highly expressed in TNBC, which may be related with the poor prognosis and may be a molecular index for predicting the prognosis of TNBC patients.

The role of heat stress on the age related protein carbonylation.

Since the proteins are involved in many physiological processes in the organisms, modifications of proteins have important outcomes. Protein modifications are classified in several ways and oxidative stress related ones take a wide place. Aging is characterized by the accumulation of oxidized proteins and decreased degradation of these proteins. On the other hand protein turnover is an important regulatory mechanism for the control of protein homeostasis. Heat shock proteins are a highly conserved family of proteins in the various cells and organisms whose expressions are highly inducible during stress conditions. These proteins participate in protein assembly, trafficking, degradation and therefore play important role in protein turnover. Although the entire functions of each heat shock protein are still not completely investigated, these proteins have been implicated in the processes of protection and repair of stress-induced protein damage. This study has focused on the heat stress related carbonylated proteins, as a marker of oxidative protein modification, in young and senescent fibroblasts. The results are discussed with reference to potential involvement of induced heat shock proteins. This article is part of a Special Issue entitled: Protein Modifications. BIOLOGICAL SIGNIFICANCE: Age-related protein modifications, especially protein carbonylation take a wide place in the literature. In this direction, to highlight the role of heat shock proteins in the oxidative modifications may bring a new aspect to the literature. On the other hand, identified carbonylated proteins in this study confirm the importance of folding process in the mitochondria which will be further analyzed in detail.

Overexpressed nuclear BAG-1 in human hepatocellular carcinoma is associated with poor prognosis and resistance to doxorubicin.

Bcl-2-associated athanogene-1 (BAG-1) is a multifunctional anti-apoptotic protein which regulates an array of cellular processes, including apoptosis, signaling, proliferation, transcription, and cell motility and has been reported to be over-expressed in a number of human malignancies. To investigate the possible involvement of BAG-1 in tumorigenesis of hepatocellular carcinoma (HCC), we performed Western blot analysis in eight paired samples of HCC and adjacent peritumoral tissues and immunohistochemistry in 65 paraffin sections of HCC, which both showed an enhanced expression of nuclear BAG-1 isoform in HCC tissues. Statistical analysis confirmed that overexpression of nuclear BAG-1 in HCC tissues was significantly associated with histological grading (P < 0.001), poor prognosis (P = 0.004), and was found to be an independent prognostic indicator for HCC (P = 0.023). We also noted that BAG-1 was overexpressed in four HCC cell lines compared with a normal hepatocyte cell line, and BAG-1 overexpression increased resistance of HCC cells to doxorubicin, a common chemotherapeutic agent for HCC. Furthermore, we observed that knock down of BAG-1 with siRNA in HepG2 cells increased the chemosensitivity of cells, a process mediated through inhibition of doxorubicin-triggered NF-κB activation; and knock down of BAG-1 suppressed proliferation and cell cycle transition of HepG2 cells. In consequence, our results for the first time indicated that BAG-1 was dysregulated in HCC and suppression of BAG-1 expression which resulted in inhibiting of NF-κB signaling might be developed into a new strategy in HCC therapy.

Bcl-2-associated athanogene 1 regulates the glucocorticoid receptor activity in rat alveolar macrophages / 医学研究生学报

Objective: To investigate the expression changes of Bcl-2-associated athanogene 1(BAG-1) and its regulatory effect on the glucocorticoid receptor(GR) activity in rat alveolar macrophages in conditions of cell inflammation and glucocorticoid therapy.Methods: The expression changes of BAG-1 were detected by Western blot after lipopolysaccharide(LPS) and Dexamethasone(Dex) treatment of rat alveolar macrophages(AMs),the interaction between BAG-1 and GR determined by immune coprecipitation experiment,and the transcriptional activation of GR measured by relative luciferase activity assay.Results:After LPS and Dex treatment,the expression of BAG-1L in total protein increased but that of BAG-1S remained changed,BAG-1L rather than BAG-1S was detected in nuclear protein and its expression increased gradually within 24 hours,the interaction between BAG-1L and GR was observed in nucleoli,and the transcriptional activation of GR decreased,with a negative correlation between BAG-1L expression and GR activity.Conclusion:LPS and Dex acting on rat alveolar macrophages,the expression of BAG-1L increases,which,coupled with GR,translocates into nucleoli and inhibits GR activity.This might be the important mechanism that underlies glucocorticoid resistance in inflammation.

BAG-1 expression changes in rat alveolar macrophage treated by lipopolysaccharide and dexamethasone / 解放军医学杂志

Objective To investigate the changes in Bcl-2-associated athanogene 1(BAG-1)expression,and the mechanism of nuclear translocation in rat alveolar macrophages(AMs)induced by lipopolysaccharide(LPS)and dexamethasone(Dex).Methods Primary culture AMs treated by LPS and Dex were divided randomly into three groups:6h group,2h group and 24h group.The BAG-1 expression in AMs was detected with Western blot.The interactions between BAG-1 and glucocorticoid receptor(GR)were detected with immune co-precipitation.The changes in GR expression in nuclear protein were evaluated with Western blotting after transfection of RNA interference recombinant plasmids(named psilencer 3.1-GR)targeting to GR gene.Results The expression of BAG-1L in total protein increased,and that of BAG-1S showed no changes.Only BAG-1L,with no BAG-1S,was detected in nuclear protein,and its expression increased gradually in 24h.Interaction between BAG-1L and GR was found in nucleolus after treatment.After transfection of plasmids psilencer 3.1-GR,the BAG-1L expression in nuclear protein decreased significantly compared with that of non-transfection group(P

THE EXPRESSION OF ANTY-APOPTOSIS PROTEIN BAG-1 IN NON-SMALL CELL LUNG CANCER AND ITS RELATIONSHIP WITH CELL APOPTOSIS AND EXPRESSION OF BCL-2 / 解剖学报

Objective To study the expression and clinical significance of anty-apoptosis protein BAG-1 in non-small cell lung cancer(NSCLC),and its relationship with cell apoptosis and expression of Bcl-2 protein. Methods Immunohisto chemistry streptavidin-peroxidase conjugated (SP)method was used to examine the expression of BAG-1protein and Bcl-2 protein,and terminal deoxynucleotidyl transferase mediated UTP nick end labeling(TUNEL) method was used to examine the apoptosis index in 54 cases of NSCLC.The expression of BAG-1 protein in 20 cases of normal bronchus mucosa tissue also be detected as control. Results Express positive rate of BAG-1 protein in NSCLC is 74.07%,obviously higher than that in normal bronchus mucosa tissue(positive rate is 5%).In cases of NSCLC,the expression of BAG-1 protein has not correlation with the age,gender,pathologic classification,but have closed correlation with lymph node metastasis,degree of differentiation,pTNM stage(P