Exome Sequencing of Normal and Isogenic Transformed Human Colonic Epithelial Cells (HCECs) Reveals Novel Genes Potentially Involved in the Early Stages of Colorectal Tumorigenesis

Biological functions and therapeutic potential of CKS2 in human cancer

The incidence of cancer is increasing worldwide and is the most common cause of death. Identification of novel cancer diagnostic and prognostic biomarkers is important for developing cancer treatment strategies and reducing mortality. Cyclin-dependent kinase subunit 2 (CKS2) is involved in cell cycle and proliferation processes, and based on these processes, CKS2 was identified as a cancer gene. CKS2 is expressed in a variety of tissues in the human body, but its abnormal expression is associated with cancer in a variety of systems. CKS2 is generally elevated in cancer, plays a role in almost all aspects of cancer biology (such as cell proliferation, invasion, metastasis, and drug resistance) through multiple mechanisms regulating certain important genes, and is associated with clinicopathological features of patients. In addition, CKS2 expression patterns are closely related to cancer type, stage and other clinical variables. Therefore, CKS2 is considered as a tool for cancer diagnosis and prognosis and may be a promising tumor biomarker and therapeutic target. This article reviews the biological function, mechanism of action and potential clinical significance of CKS2 in cancer, in order to provide a new theoretical basis for clinical molecular diagnosis, molecular targeted therapy and scientific research of cancer.

Severely polarized extracellular acidity around tumour cells

Extracellular pH impacts many molecular, cellular and physiological processes, and hence is tightly regulated. Yet, in tumours, dysregulated cancer cell metabolism and poor vascular perfusion cause the tumour microenvironment to become acidic. Here by leveraging fluorescent pH nanoprobes with a transistor-like activation profile at a pH of 5.3, we show that, in cancer cells, hydronium ions are excreted into a small extracellular region. Such severely polarized acidity (pH <5.3) is primarily caused by the directional co-export of protons and lactate, as we show for a diverse panel of cancer cell types via the genetic knockout or inhibition of monocarboxylate transporters, and also via nanoprobe activation in multiple tumour models in mice. We also observed that such spot acidification in ex vivo stained snap-frozen human squamous cell carcinoma tissue correlated with the expression of monocarboxylate transporters and with the exclusion of cytotoxic T cells. Severely spatially polarized tumour acidity could be leveraged for cancer diagnosis and therapy.

Reduced SKP2 Expression Adversely Impacts Genome Stability and Promotes Cellular Transformation in Colonic Epithelial Cells

Despite the high morbidity and mortality rates associated with colorectal cancer (CRC), the underlying molecular mechanisms driving CRC development remain largely uncharacterized. Chromosome instability (CIN), or ongoing changes in chromosome complements, occurs in ~85% of CRCs and is a proposed driver of cancer development, as the genomic changes imparted by CIN enable the acquisition of karyotypes that are favorable for cellular transformation and the classic hallmarks of cancer. Despite these associations, the aberrant genes and proteins driving CIN remain elusive. SKP2 encodes an F-box protein, a variable subunit of the SKP1-CUL1-F-box (SCF) complex that selectively targets proteins for polyubiquitylation and degradation. Recent data have identified the core SCF complex components (SKP1, CUL1, and RBX1) as CIN genes; however, the impact reduced SKP2 expression has on CIN, cellular transformation, and oncogenesis remains unknown. Using both short- small interfering RNA (siRNA) and long-term (CRISPR/Cas9) approaches, we demonstrate that diminished SKP2 expression induces CIN in both malignant and non-malignant colonic epithelial cell contexts. Moreover, temporal assays reveal that reduced SKP2 expression promotes cellular transformation, as demonstrated by enhanced anchorage-independent growth. Collectively, these data identify SKP2 as a novel CIN gene in clinically relevant models and highlight its potential pathogenic role in CRC development.

Knockdown of replication protein A 3 induces protective autophagy and enhances cisplatin sensitivity in lung adenocarcinoma by inhibiting AKT/mTOR signaling via binding to cyclin-dependent kinases regulatory subunit 2

Replication protein A 3 (RPA3) is a significant component of replication protein A and has been documented to function as an oncogene in several types of cancers. However, the role and underlying mechanism of RPA3 in lung adenocarcinoma (LUAD) remains unknown. In this study, messenger expression of RPA3 and survival probability in LUAD were predicted by the UALCAN database. The combination of RPA3 with cyclin-dependent kinases regulatory subunit 2 (CKS2) were characterized by the humanbase and STRING databases and verified by co-immunoprecipitation. Cell viability was assessed by Cell Counting Kit-8 assay and colony formation assay. Flow cytometric analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay were used to determine cell cycle and cell apoptosis, respectively. The expressions of protein kinase B/mammalian target of rapamycin (AKT/mTOR) pathway and autophagy-related proteins were examined by western blot assay. Significantly, we revealed that RPA3 expression was upregulated in LUAD and is associated with poor prognosis in LUAD patients. RPA3 and CKS2 expression was highly expressed in LUAD cell lines and the interaction between RPA3 and CKS2 was confirmed. RPA3 silencing inhibited A549 cell viability, blocked cell cycle and promoted cell apoptosis, as well as induction of autophagy and inhibition of AKT/mTOR signaling. CKS2 overexpression reversed the effects of RPA3 silencing on A549 cells. In addition, RPA3 knockdown enhanced cisplatin sensitivity of A549 cells through blocking the AKT/mTOR signaling. These results suggested that RPA3 might control LUAD cell autophagy and enhance cisplatin sensitivity by regulation of AKT/mTOR signaling via targeting CKS2.

The F-box protein, FBXO7 is required to maintain chromosome stability in humans

Despite the high morbidity and mortality rates associated with colorectal cancer (CRC), the aberrant genes and mechanisms driving CRC pathogenesis remain poorly understood. Chromosome instability (CIN), or ongoing changes in chromosome numbers, is a predominant form of genome instability associated with ~85% of CRCs, suggesting it may be a key mechanism driving CRC oncogenesis. CIN enables the acquisition of copy number alterations conferring selective growth, proliferation and survival advantages that promote cellular transformation. Despite these associations, the aberrant genes underlying CIN remain largely unknown. Candidate CIN gene FBXO7 encodes an F-box protein, a subunit of the SKP1-CUL1-FBOX (SCF) complex that confers substrate specificity to the complex and targets proteins for subsequent degradation by the 26S proteasome. Recently, the genes encoding the three core SCF complex members were identified as CIN genes; however, it is unknown whether F-box proteins exhibit similar integral roles in maintaining chromosome stability. Using short- small interfering RNA (siRNA) and long- (CRISPR/Cas9) term approaches, we show that reduced FBXO7 expression induces CIN in various colonic epithelial cell contexts, whereas FBXO7 knockout clones also exhibit hallmarks associated with cellular transformation, namely increased clonogenic and anchorage-independent growth. Collectively, these data demonstrate that FBXO7 is required to maintain genome stability identifying FBXO7 a novel CIN gene whose reduced expression may contribute to CRC development and progression.

Proteomics Analysis Identified ASNS as a Novel Biomarker for Predicting Recurrence of Skull Base Chordoma

Background

The prognostic factors of skull base chordoma associated with outcomes of patients after surgery remain inadequately identified. This study was designed to identify a novel prognostic factor for patients with skull base chordoma.

Method

Using a proteomic technique, the tumor biomarkers that were upregulated in the rapid-recurrence group of chordoma were screened and then narrowed down by bioinformatic analysis. Finally one potential biomarker was chosen for validation by immunohistochemistry using tissue microarray (TMA). A total of 187 patients included in TMA were randomly divided into two cohorts, the training cohort included 93 patients and the validation cohort included 94 patients. Kaplan-Meier survival analysis was used to assess the patients’ survival. Univariable and multivariable Cox regression analysis were used to identify prognostic factors predicting recurrence-free survival (RFS). CCK-8 assay, clonal formation assay and transwell assay were used to test the effect of asparagine synthetase (ASNS) on the proliferation, migration and invasion in chordoma cell lines.

Results

Among 146 upregulated proteins, ASNS was chosen as a potential prognostic biomarker after bioinformatics analysis. The H-scores of ASNS ranged from 106.27 to 239.58 in TMA. High expression of ASNS was correlated with shorter RFS in both the training cohort (p = 0.0093) and validation cohort (p < 0.001). Knockdown of ASNS by small interfering RNA (siRNA) inhibited the growth, colony formation, migration and invasion of chordoma cells in vitro.

Conclusion

This study indicates that high expression of ASNS is correlated with poor prognosis of patients with skull base chordoma. ASNS may be a useful prognostic factor for patients with skull base chordoma.

Direct Alkylation of Deoxyguanosine by Azaserine Leads to O6-Carboxymethyldeoxyguanosine

The O⁶-alkylguanosine adduct O⁶-carboxymethyldeoxyguanosine (O⁶-CMdG) has been detected at elevated levels in blood and tissue samples from colorectal cancer patients and from healthy volunteers after consuming red meat. The diazo compound l-azaserine leads to the formation of O⁶-CMdG as well as the corresponding methyl adduct O⁶-methyldeoxyguanosine (O⁶-MedG) in cells and is therefore in wide use as a chemical probe in cellular studies concerning DNA damage and mutation. However, there remain knowledge gaps concerning the chemical basis of DNA adduct formation by l-azaserine. To characterize O⁶-CMdG formation by l-azaserine, we carried out a combination of chemical and enzymatic stability and reactivity studies supported by liquid chromatography tandem mass spectrometry for the simultaneous quantification of O⁶-CMdG and O⁶-MedG. We found that l-azaserine is stable under physiological and alkaline conditions as well as in active biological matrices but undergoes acid-catalyzed hydrolysis. We show, for the first time, that l-azaserine reacts directly with guanosine (dG) and oligonucleotides to form an O⁶-serine-CMdG (O⁶-Ser-CMdG) adduct. Moreover, by characterizing the reaction of dG with l-azaserine, we demonstrate that O⁶-Ser-CMdG forms as an intermediate that spontaneously decomposes to form O⁶-CMdG. Finally, we quantified levels of O⁶-CMdG and O⁶-MedG in a human cell line exposed to l-azaserine and found maximal adduct levels after 48 h. The findings of this work elucidate the chemical basis of how l-azaserine reacts with deoxyguanosine and support its use as a chemical probe for N-nitroso compound exposure in carcinogenesis research, particularly concerning the identification of pathways and factors that promote adduct formation.

Role and mechanism of FLNa and UCP2 in the development of cervical cancer

Recent studies have reported that filamin A (FLNa) and uncoupling protein 2 (UCP2) are highly expressed in various types of cancer, but little is currently known about their roles in cervical cancer (CC). In the present study, immunohistochemical staining of paraffin sections of cervical tissues was performed in order to compare the differential expression of FLNa, UCP2, p16 and Ki67 between CC and high-grade intraepithelial neoplasia (HSIL). UCP2 and FLNa were knocked down in CC cell lines to investigate the effects on cell proliferation, cell cycle arrest, apoptosis, migration and invasion. In addition, the present study investigated the expression of cell-associated proteins [extracellular signal-regulated kinase (ERK), phosphorylated (p) ERK, protein kinase B (AKT), p-AKT and B-cell lymphoma-2 (Bcl-2)] and the mRNA levels of cellular proteins such as Ras, matrix metalloproteinase (MMP)-2 and MMP-9. FLNa and UCP2 expression levels were significantly higher in CC tissues than in HSIL tissues, with no significant differential expression of p16 or Ki67. UCP2 expression was significantly different in patients with clinical stage II or higher or lymph node metastasis compared with in other patients with cervical cancer. FLNa or UCP2 knockdown slowed or decreased SiHa and HeLa cell proliferation, migration and invasion, with no significant change in apoptosis, and downregulated the protein levels of p-ERK1/2, and the mRNA levels of Ras, MMP-2 and MMP-9. UCP2 knockdown arrested the cell cycle at the G₂ phase in SiHa and HeLa cells, while FLNa knockdown arrested the cell cycle at the G₂ phase in HeLa cells. The results of the present study revealed that FLNa and UCP2 play roles in the development and progression of CC via the Ras/MAPK/ERK signalling pathway. FLNa and UCP2 are superior to p16 and Ki67 for early prediction of CC, indicating that FLNa and UCP2 may be used for the early diagnosis of CC. UCP2 may be used to predict the prognosis of CC.

Quantitative mitochondrial DNA copy number determination using droplet digital PCR with single-cell resolution

Mitochondria are involved in a number of diverse cellular functions, including energy production, metabolic regulation, apoptosis, calcium homeostasis, cell proliferation, and motility, as well as free radical generation. Mitochondrial DNA (mtDNA) is present at hundreds to thousands of copies per cell in a tissue-specific manner. mtDNA copy number also varies during aging and disease progression and therefore might be considered as a biomarker that mirrors alterations within the human body. Here, we present a new quantitative, highly sensitive droplet digital PCR (ddPCR) method, droplet digital mitochondrial DNA measurement (ddMDM), to measure mtDNA copy number not only from cell populations but also from single cells. Our developed assay can generate data in as little as 3 h, is optimized for 96-well plates, and also allows the direct use of cell lysates without the need for DNA purification or nuclear reference genes. We show that ddMDM is able to detect differences between samples whose mtDNA copy number was close enough as to be indistinguishable by other commonly used mtDNA quantitation methods. By utilizing ddMDM, we show quantitative changes in mtDNA content per cell across a wide variety of physiological contexts including cancer progression, cell cycle progression, human T cell activation, and human aging.

Single Chromosome Aneuploidy Induces Genome-Wide Perturbation of Nuclear Organization and Gene Expression

Chromosomal aneuploidy is a defining feature of carcinomas and results in tumor-entity specific genomic imbalances. For instance, most sporadic colorectal carcinomas carry extra copies of chromosome 7, an aneuploidy that emerges already in premalignant adenomas, and is maintained throughout tumor progression and in derived cell lines. A comprehensive understanding on how chromosomal aneuploidy affects nuclear organization and gene expression, i.e., the nucleome, remains elusive. We now analyzed a cell line established from healthy colon mucosa with a normal karyotype (46,XY) and its isogenic derived cell line that acquired an extra copy of chromosome 7 as its sole anomaly (47,XY,+7). We studied structure/function relationships consequent to aneuploidization using genome-wide chromosome conformation capture (Hi-C), RNA sequencing and protein profiling. The gain of chromosome 7 resulted in an increase of transcript levels of resident genes as well as genome-wide gene and protein expression changes. The Hi-C analysis showed that the extra copy of chromosome 7 is reflected in more interchromosomal contacts between the triploid chromosomes. Chromatin organization changes are observed genome-wide, as determined by changes in A/B compartmentalization and topologically associating domain (TAD) boundaries. Most notably, chromosome 4 shows a profound loss of chromatin organization, and chromosome 14 contains a large A/B compartment switch region, concurrent with resident gene expression changes. No changes to the nuclear position of the additional chromosome 7 territory were observed when measuring distances of chromosome painting probes by interphase FISH. Genome and protein data showed enrichment in signaling pathways crucial for malignant transformation, such as the HGF/MET-axis. We conclude that a specific chromosomal aneuploidy has profound impact on nuclear structure and function, both locally and genome-wide. Our study provides a benchmark for the analysis of cancer nucleomes with complex karyotypes.

Role of DDX3 in the pathogenesis of inflammatory bowel disease

When crypt stem cells of the gastrointestinal tract become injured, the result is increased synthesis of pro-inflammatory cytokines and matrix metalloproteinases by their progeny – the colonic epithelium. Chronic inflammation of the gastrointestinal tract is a characteristic of inflammatory bowel disease, which includes Crohn’s Disease and Ulcerative Colitis. In our ongoing investigation to decipher the characteristic functions of a RNA helicase gene, DDX3, we identified high DDX3 expression by immunohistochemistry of colon biopsy samples, which included chronic/mild Morbus Crohn, active Morbus Crohn, Chronic/mild Colitis Ulcerosa and active Colitis Ulcerosa in epithelium and stromal compartments. We used a small molecule inhibitor of DDX3, RK-33, on two human colonic epithelial cell lines, HCEC1CT and HCEC2CT and found that RK-33 was able to decrease expression of MMP-1, MMP-2, MMP-3, and MMP-10. Moreover, forced differentiation of a human colonic cancer cell line, HT29, resulted in decreased DDX3 levels, indicating that DDX3 contributes to the modulation of colonic epithelium differentiation. In conclusion, our results revealed novel functions of DDX3 in inflammatory bowel disease and indicate a potential for using RK-33 as a systemic therapy to promote not only differentiation of transformed colonic epithelium but also to reduce MMP expression and thus elicit a decreased inflammatory response.

Elevated Expression of RPA3 Is Involved in Gastric Cancer Tumorigenesis and Associated with Poor Patient Survival

BACKGROUND

The replication protein A3 (RPA3) is a component of the RPA protein complex, which plays an essential role in multiple processes of DNA metabolism.

AIMS

However, the involvement of RPA3 in gastric cancer tumorigenesis has not yet been investigated.

METHODS

We stably knocked down RPA3 expression using short hairpin RNA in AGS cell line, and performed cell growth, colony formation and soft agar assays. Xenograft experiments were performed to examine tumor promoting properties of RPA3 in vivo. The qRT-PCR and immunohistochemistry were performed to evaluate RPA3 expression levels in 37 and 12 pairs of gastric cancer patient samples, respectively. Association between RPA3 expression and survival was evaluated in an independent cohort of 85 gastric cancer patients.

RESULTS

Downregulation of RPA3 inhibited cell growth, clonogenicity and soft agar growth in AGS cells. Decreased expression of RPA3 significantly reduced tumor growth rate in AGS xenografts. In addition, RPA3 was upregulated in cancerous tissues compared with matched noncancerous adjacent tissues in gastric cancer patients. High expression of RPA3 was associated with poor patient survival.

CONCLUSION

Upregulation of RPA3 is involved in gastric cancer tumorigenesis and is associated with poorer patient survival. RPA3 represents a new therapeutic target of gastric cancer and serves as a potential prognostic biomarker for patient survival in gastric cancer.

Replication Protein A 3 Is Associated with Hepatocellular Carcinoma Tumorigenesis and Poor Patient Survival

BACKGROUND

Replication protein A (RPA) 3 is a subunit of the RPA protein complex, which functions in multiple processes of DNA metabolism. Dysregulation of RPA1 and RPA2 has been implicated in tumor progression in several cancer types. However, the function of RPA3 in hepatocellular carcinoma (HCC) tumorigenesis has not been elucidated.

METHOD

In this study, we investigated the function of RPA3 in HCC development by stably knocking down its expression using short hairpin RNA (shRNA) in HepG2 cell line, followed by cell proliferation, colony formation, soft agar, and invasion assays. Xenograft experiment was performed to examine in vivo tumor-promoting properties of RPA3.

RESULTS

Downregulation of RPA3-inhibited cell proliferation, colony formation, soft agar growth as well as invasion in HepG2 cells were observed. Stable knockdown of RPA3 significantly inhibited tumor growth in the xenograft mouse model. In addition, qRT-PCR analysis revealed that RPA3 was upregulated in human HCC tissues compared with matched noncancerous adjacent tissues (NATs). High expression of RPA3 was associated with poor overall survival and disease-free survival.

CONCLUSION

Elevated expression of RPA3 promotes tumor progression in HCC cells. RPA3 is upregulated in HCC tissues and high expression of RPA3 is associated with poorer patient survival. Therefore, this protein may represent a novel therapeutic target for intervention of HCC and prognostic biomarker for patient survival.

Elevated Expression of ERCC6 Confers Resistance to 5-Fluorouracil and Is Associated with Poor Patient Survival in Colorectal Cancer

Excision repair cross-complementation (ERCC) enzymes are key members of the nucleotide excision repair pathway. Dysregulation of ERCC family members has been shown to be involved in chemoresistance in several malignancies. However, the function of ERCC6 in regulating chemo response has not been evaluated in colorectal cancer (CRC). We stably knocked down ERCC6 expression using short hairpin RNA (shRNA) in HCT116 and DLD1 human colon cancer cell lines, followed by chemosensitivity assay. In vivo chemosensitizing effects of ERCC6 were examined in xenograft experiments. Downregulation of ERCC6 conferred sensitivity to 5-fluorouracil (5-FU) in HCT116 and DLD1 cells. Stable knockdown of ERCC6 significantly enhanced antitumor activity of 5-FU in HCT116 xenograft mouse model. ERCC6 was upregulated in CRC tissues compared to matched noncancerous adjacent tissues and was also upregulated in patients who were resistant to 5-FU treatment. In addition, high expression of ERCC6 was associated with poor overall survival in CRC patients with or without receiving 5-FU therapy. Elevated expression of ERCC6 contributes to chemoresistance in CRC cells. Low ERCC6 expression is associated with better chemo response and survival in CRC patients. Therefore, this protein represents a novel therapeutic target for improvement of chemotherapeutic efficacy and predictive biomarker for patient survival.

miRNA-24-3p promotes cell proliferation and regulates chemosensitivity in head and neck squamous cell carcinoma by targeting CHD5

Aim: To investigate the role of miR-24-3p in tumorigenesis and chemosensitivity in head and neck squamous cell carcinoma (HNSCC). Methods: Growth rate and colony formation assays were performed after transfection with miR-24-3p mimic and inhibitor in cultured SCC-15 cells, followed by a CellTiter-Glo® assay. Western blot and luciferase assays were performed to investigate the direct target of miR-24-3p. Xenograft mouse model was used to evaluate combinatorial effects of miR-24-3p inhibitor and 5-fluorouracil. Results & conclusion: Inhibition of miR-24-3p reduced cell proliferation, colony formation efficiency and reversed chemoresistance in HNSCC cells. CHD5 is the direct target of miR-24-3p which is required for the regulatory role of miR-24-3p in chemoresistance. miR-24-3p may represent a new therapeutic target for the improvement of clinical outcome in HNSCC.

Down-regulation of protein kinase, DNA-activated, catalytic polypeptide attenuates tumor progression and is an independent prognostic predictor of survival in prostate cancer

OBJECTIVE

Protein kinase, DNA-activated, catalytic polypeptide (PRKDC) is a critical component of DNA repair machinery and its dysregulated expression has been observed in various cancer types or premalignant cells. However, its role in prostate cancer (PCa) development and its prognostic significance in PCa is unknown.

METHODS

The mRNA and protein levels of PRKDC were analyzed in 15 pairs of PCa and benign prostatic hyperplasia tissues as well as PCa cell lines by quantitative real-time polymerase chain reaction and Western blot, respectively. Small interfering RNA and short hairpin RNA-mediated knockdown of PRKDC, followed by cell proliferation, colony formation, and soft agar assays were performed. Xenograft mouse model was used to evaluate in vivo effects of PRKDC knockdown. The association between PRKDC expression and clinicopathologic features was assessed by χ² tests. Kaplan-Meier analysis was performed to investigate the association between PRKDC expression and overall survival. Cox proportional hazards regression models were used to examine the prognostic significance of PRKDC.

RESULTS

Expression of PRKDC mRNA and protein was notably higher in PCa tissues and PCa cell lines. Knockdown of PRKDC markedly reduced cell proliferation, colony formation efficiency, and soft agar growth in DU145 cells. Down-regulation of PRKDC inhibited tumor growth of DU145 xenografts and enhance mice survival. In addition, PRKDC expression in PCa was significantly associated with Gleason score (P = 0.01), tumor stage (P = 0.028), and distant metastasis (P = 0.025). Patients with PCa having higher PRKDC expression had substantially shorter survival than patients with lower PRKDC expression.

CONCLUSION

Down-regulation of PRKDC attenuates tumor progression in PCa. PRKDC may potentially be a prognostic biomarker in PCa.

Knockdown of asparagine synthetase (ASNS) suppresses cell proliferation and inhibits tumor growth in gastric cancer cells

OBJECTIVE

Asparagine synthetase (ASNS) gene encodes an enzyme that catalyzes the glutamine- and ATP-dependent conversion of aspartic acid to asparagine. ASNS is deemed as a promising therapeutic target and its expression is associated with the chemotherapy resistance in several human cancers. However, its role in gastric cancer tumorigenesis has not been investigated.

METHODS

In this study, we employed small interfering RNA (siRNA) to transiently knockdown ASNS in two gastric cancer cell lines, AGS and MKN-45, followed by growth rate assay and colony formation assay. Dose response curve analysis was performed in AGS and MKN-45 cells with stable ASNS knockdown to assess sensitivity to cisplatin. Xenograft experiment was performed to examine in vivo synergistic effects of ASNS depletion and cisplatin on tumor growth. Expression level of ASNS was evaluated in human patient samples using quantitative PCR. Kaplan-Meier curve analysis was performed to evaluate association between ASNS expression and patient survival.

RESULTS

Transient knockdown of ASNS inhibited cell proliferation and colony formation in AGS and MKN-45 cells. Stable knockdown of ASNS conferred sensitivity to cisplatin in these cells. Depletion of ASNS and cisplatin treatment exerted synergistic effects on tumor growth in AGS xenografts. Moreover, ASNS was found to be up-regulated in human gastric cancer tissues compared with matched normal colon tissues. Low expression of ASNS was significantly associated with better survival in gastric cancer patients.

CONCLUSION

ASNS may contribute to gastric cancer tumorigenesis and may represent a novel therapeutic target for prevention or intervention of gastric cancer.

MicoRNA-425-5p is a potential prognostic biomarker for cervical cancer

Background

MicroRNAs have been implicated in many biological pathways involved in tumourigenesis and can serve as prognostic biomarkers in many cancer types. The present study aims at evaluating the prognostic significance of miR-425-5p in cervical cancer.

Methods

Real-time polymerase chain reaction was performed to assess the expression levels of miR-425-5p in 35 pairs of cervical cancer tissues and their matched normal tissues as well as serum samples from 40 cervical cancer patients, 13 benign cervical disease patients and 32 healthy controls. The association between miR-425-5p expression levels in tissue and serum, and clinicopathological factors was examined. The correlation between serum miR-425-5p expression levels and overall survival of cervical cancer patients was assessed by Kaplan–Meier analysis and Cox proportional hazards model.

Results

MiR-425-5p expression levels were significantly increased in cervical cancer tissues compared with matched non-cancerous tissues. Higher expression of miR-425-5p was positively associated with high tumour stage ( P = 0.0003) and positive lymph node metastasis ( P = 0.0107). Serum concentrations of miR-425-5p in cervical cancer patients were significantly higher compared with benign cervical disease and healthy controls. Moreover, the up-regulation of serum miR-425-5p occurred more frequently in cervical cancer patients with high TNM stage ( P = 0.0003) and positive lymph node metastasis ( P = 0.0037). Kaplan–Meier analysis showed that high serum miR-425-5p expression levels predicted poor survival ( P = 0.0571). Cox proportional hazards risk analysis demonstrated that miR-425-5p was an independent prognostic factor for cervical cancer.

Conclusion

Our study suggests that miR-425-5p is up-regulated in cervical cancer and serum miR-425-5p may serve as a potential prognostic biomarker for cervical cancer.

FLNA is a predictor of chemoresistance and poor survival in cervical cancer

Aim: To investigate the expression of FLNA and its potential prognostic significance in cervical cancer. Patients & methods: Real-time PCR was performed to evaluate the expression levels of FLNA in 44 pairs of cervical cancer and matched normal adjacent tissues. Kaplan–Meier analysis and Cox proportional hazards model were used to examine the correlation between FLNA expression levels and overall survival in cervical cancer patients. Results & conclusion: FLNA was significantly upregulated in cervical cancer tissues. FLNA expression level was associated with lymph node metastasis, parametrial invasion and response to neoadjuvant chemotherapy and predicted poor survival in cervical cancer patients. FLNA may serve as a predictor of chemosensitivity and a prognostic biomarker of survival in cervical cancer.

miR-186 regulates chemo-sensitivity to paclitaxel via targeting MAPT in non-small cell lung cancer (NSCLC)

miR-186 has been reported to be implicated in tumorigenesis and chemoresistance in a few cancer types.