BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

Loss of protein homeostasis is a hallmark of cellular senescence, and ribosome pausing plays a crucial role in the collapse of proteostasis. However, our understanding of ribosome pausing in senescent cells remains limited. In this study, we utilized ribosome profiling and G-quadruplex RNA immunoprecipitation sequencing techniques to explore the impact of RNA G-quadruplex (rG4) on the translation efficiency in senescent cells. Our results revealed a reduction in the translation efficiency of rG4-rich genes in senescent cells and demonstrated that rG4 structures within coding sequence can impede translation both in vivo and in vitro. Moreover, we observed a significant increase in the abundance of rG4 structures in senescent cells, and the stabilization of the rG4 structures further exacerbated cellular senescence. Mechanistically, the RNA helicase DHX9 functions as a key regulator of rG4 abundance, and its reduced expression in senescent cells contributing to increased ribosome pausing. Additionally, we also observed an increased abundance of rG4, an imbalance in protein homeostasis, and reduced DHX9 expression in aged mice. In summary, our findings reveal a novel biological role for rG4 and DHX9 in the regulation of translation and proteostasis, which may have implications for delaying cellular senescence and the aging process.
G-Quadruplexes ; Cellular Senescence ; Ribosomes/genetics* ; Humans ; Animals ; Mice ; DEAD-box RNA Helicases/genetics* ; Protein Biosynthesis ; RNA/chemistry* ; Neoplasm Proteins

MTUS1 (microtubule-associated tumor suppressor 1) has been identified that can function as a tumor suppressor gene in many malignant tumors. However, the function and mechanisms underlying the regulation of MTUS1 are unclear. In the present study, we reported that miR-19a and miR-19b (miR-19a/b) promote proliferation and migration of lung cancer cells by targeting MTUS1. First, MTUS1 was proved to function as a tumor suppressor in lung cancer and was linked to cell proliferation and migration promotion. Second, an inverse correlation between miR-19a/b expression and MTUS1 mRNA/protein expression was noted in human lung cancer tissues. Third, MTUS1 was appraised as a direct target of miR-19a/b by bioinformatics analysis. Fourth, direct MTUS1 regulation by miR-19a/b in lung cancer cells was experimentally affirmed by cell transfection assay and luciferase reporter assay. Finally, miR-19a/b were shown to cooperatively repress MTUS1 expression and synergistically regulate MTUS1 expression to promote lung cancer cell proliferation and migration. In conclusion, our findings have provided the first clues regarding the roles of miR-19a/b, which appear to function as oncomirs in lung cancer by downregulating MTUS1.
A549 Cells ; Cell Movement ; Cell Proliferation ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Male ; MicroRNAs ; genetics ; metabolism ; RNA, Neoplasm ; genetics ; metabolism ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVE: We aimed to evaluate the prognostic and predictive value of the nucleotide excision repair-related gene GTF2H5, which is localized at the 6q24.2-26 deletion previously reported by our group to predict longer survival of high-grade serous ovarian cancer patients. METHODS: In order to test if protein levels of GTF2H5 are associated with patients' outcome, we performed GTF2H5 immunohistochemical staining in 139 high-grade serous ovarian carcinomas included in tissue microarrays. Upon stratification of cases into high- and low-GTF2H5 staining categories (> and < or = median staining, respectively) Kaplan-Meier and log-rank test were used to estimate patients' survival and assess statistical differences. We also evaluated the association of GTF2H5 with survival at the transcriptional level by using the on-line Kaplan-Meier plotter tool, which includes gene expression and survival data of 855 high-grade serous ovarian cancer patients from 13 different datasets. Finally, we determined whether stable short hairpin RNA-mediated GTF2H5 downregulation modulates cisplatin sensitivity in the SKOV3 and COV504 cell lines by using cytotoxicity assays. RESULTS: Low expression of GTF2H5 was associated with longer 5-year survival of patients at the protein (hazard ratio [HR], 0.52; 95% CI, 0.29 to 0.93; p=0.024) and transcriptional level (HR, 0.80; 95% CI, 0.65 to 0.97; p=0.023) in high-grade serous ovarian cancer patients. We confirmed the association with 5-year overall survival (HR, 0.55; 95% CI, 0.38 to 0.78; p=0.0007) and also found an association with progression-free survival (HR, 0.72; 95% CI, 0.54 to 0.96; p=0.026) in a homogenous group of 388 high-stage (stages III-IV using the International Federation of Gynecology and Obstetrics staging system), optimally debulked high-grade serous ovarian cancer patients. GTF2H5-silencing induced a decrease of the half maximal inhibitory concentration upon cisplatin treatment in GTF2H5-silenced ovarian cancer cells. CONCLUSION: Low levels of GTF2H5 are associated with enhanced prognosis in high-grade serous ovarian cancer patients and may contribute to cisplatin sensitization.
Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor/biosynthesis/genetics ; Cystadenocarcinoma, Serous/*genetics/metabolism/pathology ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Kaplan-Meier Estimate ; Middle Aged ; Neoplasm Grading ; Neoplasm Proteins/biosynthesis/genetics ; Neoplasms, Glandular and Epithelial/*genetics/metabolism/pathology ; Ovarian Neoplasms/*genetics/metabolism/pathology ; Prognosis ; Transcription Factors/biosynthesis/*genetics ; Tumor Cells, Cultured

OBJECTIVETo analyze the clinicopathological characteristics of patients with anaplastic lymphoma kinase (ALK) rearrangements in lung adenocarcinoma, and the clinical therapy and prognosis of the patients.

METHODSClinicopathological data of 34 cases of ALK-positive patients treated in the Beijing Chest Hospital from 2005 to 2014 were reviewed. The expression of ALK proteins in the resected tumors was detected by immunohistochemistry, and EGFR mutations were examined by polymerase chain reaction and a direct DNA sequencing method.

RESULTSAmong the 34 patients, 20 were male and 14 were female, the median age was 49, and 11 were smokers and 23 were never smokers. The clinical stages of the patients were stage IA in 5 patients, IB in one patient, IIA in two patients, IIIA in 16 patients, IIIB in 5 patients, IV in 4 patients, and one patient of unknown stage. ALK-positive tumors showed strong granular staining in cell cytoplasm by immunohistochemistry. Forteen patients were solid predominant subtype with mucin production, 10 of acinar predominant subtype, 6 of papillary predominant subtype, 3 of micropapillary predominant subtype, and one was of colloid variant. There were 18 cases with mucin production, 6 cases had signet-ring cell morphology, and 10 cases showed cribriform pattern. Only one patient had coexistence of ALK rearrangement and EGFR mutation (L858R at exon 21). Of the 34 patients, 24 patients were followed up. The median follow up of the 24 patients was 11.0 months (1.7-48.7 months).

CONCLUSIONSALK-positive tumors as a molecular subtype of lung adenocarcinoma have distinct clinicopathological features. The histological findings of ALK-positive tumors are characterized by solid predominant subtype with mucin production, acinar predominant subtype, signet-ring cells and cribriform structures. They were rarely co-mutated with EGFR mutation.

Adenocarcinoma ; enzymology ; pathology ; therapy ; Exons ; Female ; Gene Rearrangement ; Genes, erbB-1 ; Humans ; Immunohistochemistry ; Lung Neoplasms ; enzymology ; pathology ; therapy ; Male ; Middle Aged ; Mucins ; biosynthesis ; Mutation ; Neoplasm Proteins ; genetics ; Polymerase Chain Reaction ; Prognosis ; Receptor Protein-Tyrosine Kinases ; genetics ; Sequence Analysis, DNA

The Wnt signaling pathway has regulatory roles in cell proliferation, differentiation, and polarity. Aberrant Wnt pathway regulation can lead to abnormal cell proliferation and cancer, and loss of Wnt7a expression has been demonstrated in lung cancer cell lines. E-cadherin keeps intercellular integrity and prevents metastasis. Therefore, E-cadherin has been known as a prognostic factor in cancer. In the present study, we investigated the E-cadherin expression status by immunohistochemical stain and the Wnt7a promoter methylation status in human non-small cell lung carcinoma (NSCLC) by methylation-specific PCR. We also analyzed their correlations with clinicopathological factors. Methylation of the Wnt7a gene promoter was detected in the lung tissues of 32 of 121 (26.4%) patients with NSCLC. Wnt7a promoter methylation was correlated with advanced tumor stage (P = 0.036) and distant metastasis (P = 0.037). In addition, Wnt7a promoter methylation showed correlation with loss of E-cadherin expression (P < 0.001). However, Wnt7a promoter methylation was not closely related with gender, age, histological type, or smoking habit. Even though Wnt7a methylation could not show significant correlation with the long term survival of the patients with limited follow up data, these findings suggest that loss of the Wnt7a gene induced by promoter methylation might be another prognostic factor for NSCLC and that restoration of Wnt7a may be a promising treatment for NSCLC.
Cadherins/biosynthesis ; Carcinoma, Non-Small-Cell Lung/*genetics/mortality ; DNA Methylation/*genetics ; Female ; Humans ; Lung Neoplasms/*genetics/mortality ; Male ; Middle Aged ; Neoplasm Metastasis/genetics ; Neoplasm Staging ; Promoter Regions, Genetic/*genetics ; Republic of Korea ; Tumor Markers, Biological/genetics ; Wnt Proteins/*genetics

The Wnt signaling pathway has regulatory roles in cell proliferation, differentiation, and polarity. Aberrant Wnt pathway regulation can lead to abnormal cell proliferation and cancer, and loss of Wnt7a expression has been demonstrated in lung cancer cell lines. E-cadherin keeps intercellular integrity and prevents metastasis. Therefore, E-cadherin has been known as a prognostic factor in cancer. In the present study, we investigated the E-cadherin expression status by immunohistochemical stain and the Wnt7a promoter methylation status in human non-small cell lung carcinoma (NSCLC) by methylation-specific PCR. We also analyzed their correlations with clinicopathological factors. Methylation of the Wnt7a gene promoter was detected in the lung tissues of 32 of 121 (26.4%) patients with NSCLC. Wnt7a promoter methylation was correlated with advanced tumor stage (P = 0.036) and distant metastasis (P = 0.037). In addition, Wnt7a promoter methylation showed correlation with loss of E-cadherin expression (P < 0.001). However, Wnt7a promoter methylation was not closely related with gender, age, histological type, or smoking habit. Even though Wnt7a methylation could not show significant correlation with the long term survival of the patients with limited follow up data, these findings suggest that loss of the Wnt7a gene induced by promoter methylation might be another prognostic factor for NSCLC and that restoration of Wnt7a may be a promising treatment for NSCLC.
Cadherins/biosynthesis ; Carcinoma, Non-Small-Cell Lung/*genetics/mortality ; DNA Methylation/*genetics ; Female ; Humans ; Lung Neoplasms/*genetics/mortality ; Male ; Middle Aged ; Neoplasm Metastasis/genetics ; Neoplasm Staging ; Promoter Regions, Genetic/*genetics ; Republic of Korea ; Tumor Markers, Biological/genetics ; Wnt Proteins/*genetics

This study investigated the effects of miRNA-155 on malignant biological characteristics of NK/T-cell lymphoma cell lines and the possible mechanism. The expression of miRNA-155 was detected in lymphoma cell lines from different sources (SNK-6, YTS, Jurkat and DOHH2) by real-time PCR. Lentiviral vectors (pLL3.7) that could overexpress or downexpress miRNA-155 were constructed. Recombinant lentiviral particles were prepared and purified, and their titers determined. The expression of miRNA-155 in the infected SNK-6 cells and the cell proliferation were detected by PCR and CCK-8, respectively. Flow cytometry was used to determine the apoptosis of infected SNK-6 cells. The target of miRNA155 was predicted from Targetscan website. The effect of miRNA155 on FOXO3a expression was examined by Western blotting. The results showed that among the human NK/T-cell lymphoma cell lines SNK-6, YTS, Jurkat and DOHH2, the expression of miRNA-155 was highest in SNK-6. The infection efficiency of the recombinant lentivirus in SNK-6 was more than 70% at multiplicity of infection (MOI) of 100. The expression of miRNA-155 was significantly increased in SNK-6 cells infected by lentivirus vectors with high expression of miRNA-155 (4 times higher than the control group), and profoundly decreased in those infected with lentiviruses with low expression of miRNA-155. The proliferation of letivirus-infected SNK-6 cells was decreased as the expression of miRNA-155 reduced. The apoptosis rate was increased with the reduction in the expression of miRNA-155. FOXO3a was found to be a possible target of miRNA155, as suggested by Targetscan website. Western blotting showed that the expression of FOXO3a was significantly elevated in SNK-6 cells with miRNA-155 inhibition. It was concluded that reduction in miRNA-155 expression can inhibit the proliferation of SNK-6 lymphoma cells and promote their apoptosis, which may be associated with regulation of FOXO3a gene.
Apoptosis ; genetics ; Forkhead Box Protein O3 ; Forkhead Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Humans ; Jurkat Cells ; Lymphoma, T-Cell ; genetics ; metabolism ; pathology ; MicroRNAs ; biosynthesis ; genetics ; Natural Killer T-Cells ; metabolism ; pathology ; Neoplasm Proteins ; genetics ; metabolism ; RNA, Neoplasm ; biosynthesis ; genetics ; Transduction, Genetic

Estrogen-related receptor alpha (ERRα) plays an important role in the development of hormone-dependent cancers, but its roles in lung cancer remain elusive. The present study was aimed to investigate the effects of ERRα on the proliferation and metastasis of lung cancer A549 cells. The mRNA and protein levels of ERRα were detected in lung cancer A549 and MCF-7 cells and bronchial epithelial BEAS-2B cells by qRT-PCR and Western blotting, respectively. ERRα plasmid transfection and XCT-790 (an inverse agonist of ERRα) were used to up-regulate or down-regulate ERRα expression in A549 cells, respectively. The viability of A549 cells was measured by cell counting kit-8 (CCK-8) and the motility of A549 cells by wound healing assay and Transwell migration/invasion assay. The epithelial markers E-cadherin (E-Cad) and zona occludin-1 (ZO-1), the mesenchymal markers fibronectin (FN) and vimentin (Vim) and the transcription factors (Snail, Zeb1 Twist and Slug) were further detected at mRNA and protein levels by qRT-PCR and Western blotting, respectively. The results showed that ERRα promoted the growth of lung cancer A549 cells in vitro. XCT-790 significantly inhibited the migration and invasion of A549 cells. Over-expression of ERRα promoted the epithelial-to-mesenchymal transition (EMT) of A549 cells, down-regulated the epithelial makers E-Cad and ZO-1, and up-regulated the mesenchymal makers FN and Vim. Silencing of Slug, but not other transcription factors, significantly abolished the ERRα-induced EMT of A549 cells. It was suggested that ERRα promoted the migration and invasion of A549 cells by inducing EMT, and Slug was involved in the process. Targeting ERRα might be an efficient approach for lung cancer treatment.
Cell Line, Tumor ; Cell Proliferation ; Epithelial-Mesenchymal Transition ; Gene Expression Regulation ; Humans ; Lung Neoplasms ; genetics ; metabolism ; prevention & control ; Neoplasm Metastasis ; Neoplasm Proteins ; biosynthesis ; genetics ; Receptors, Estrogen ; biosynthesis ; genetics

miR-200c has been shown to regulate the epithelial-mesenchymal transition (EMT) by inhibiting ZEB1 and ZEB2 expression in breast cancer cells. This study further examined the role of miR-200c in the invasion and metastasis of breast cancer that goes beyond the regulation on ZEB1 and ZEB2 expression. In this study, the bioinformatics software (miRanda) was used to predict the target gene of miR-200c and Renilla luciferase assay to verify the result. The metastatic breast cancer cells MDA-MB-231 were cultured and transfected with the miR-200c mimic or inhibitor. The expressions of miR-200c and HMGB1 were detected by RT-PCR and Western blotting, respectively. Transwell assay and wound healing assay were employed to examine the invasive and migrating ability of transfected cells. Target prediction and Renilla luciferase analysis revealed that HMGB1 was a putative target gene of miR-200c. After transfection of MDA-MB-231 cells with the miR-200c mimic or inhibitor, the expression of miR-200c was significantly increased or decreased when compared with cells transfected with the miR-200c mimic NC or inhibitor NC. Moreover, the expression of HMGB1 was reversely correlated with that of miR-200c in transfected cells. Tranwell assay showed that the number of invasive cells was significantly reduced in miR-200c mimic group when compared with miR-200c inhibitor group. It was also found that the migrating ability of cells transfected with miR-200c mimics was much lower than that of cells transfected with miR-200c inhibitors. It was suggested that miR-200c can suppress the invasion and migration of breast cancer cells by regulating the expression of HMGB1. miR-200c and HMGB1 may become useful biomarkers for progression of breast cancer and targets of gene therapy.
Biomarkers, Tumor ; Breast Neoplasms ; genetics ; metabolism ; Cell Movement ; genetics ; Epithelial-Mesenchymal Transition ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; HEK293 Cells ; HMGB1 Protein ; genetics ; Homeodomain Proteins ; biosynthesis ; Humans ; MicroRNAs ; genetics ; Neoplasm Invasiveness ; genetics ; Neoplasm Metastasis ; genetics ; pathology ; Repressor Proteins ; biosynthesis ; Transcription Factors ; biosynthesis ; Zinc Finger E-box Binding Homeobox 2 ; Zinc Finger E-box-Binding Homeobox 1