LOC101929709 promotes gastric cancer progression by aiding LIN28B to stabilize c-MYC mRNA.

BACKGROUND: LIN28B plays a critical role in the Warburg effect. However, its underlying mechanism remains elusive. Recently, it has been reported that LIN28B could collaborate with IGF2BP3, which can bind to m6A-modified c-MYC transcripts. Therefore, this study investigated if LIN28B recognises methylated c-MYC mRNA to promote the Warburg effect in gastric cancer. METHODS: Effects of LIN28B on gastric cancer were confirmed in vitro and in vivo. On the basis of bioinformatics analysis, the association between LIN28B and c-MYC mRNA was shown using RNA immunoprecipitation (RIP) and luciferase reporter assays. The role of m6A was identified by RNA pull-down assays. We further performed RIP-seq to search for long non-coding RNAs (lncRNAs) participating in the LIN28B binding process. Chromatin immunoprecipitation was used to show the impact of c-MYC on transcription of LIN28B and lncRNAs. RESULTS: LIN28B was identified to stabilize c-MYC mRNA by recognizing m6A. Furthermore, the interaction between c-MYC mRNA and LIN28B is speculated to be supported by LOC101929709, which binds to both LIN28B and IGF2BP3. Functional experiments revealed that LOC101929709 promotes the proliferation, migration and glycolysis of gastric cancer. Mechanistically, LOC101929709 enriched in the cytoplasm helps LIN28B stabilize c-MYC mRNA. Moreover, c-MYC promoted the transcription of both LOC101929709 and LIN28B. Additionally, LOC101929709 also activated the PI3K/AKT pathway. CONCLUSIONS: The c-MYC/LOC101929709/LIN28B axis promotes aerobic glycolysis and tumour progression. Thus, LOC101929709 can be a novel potential target for gastric cancer treatment.

TBX15/miR-152/KIF2C pathway regulates breast cancer doxorubicin resistance via promoting PKM2 ubiquitination.

BACKGROUND: Chemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer. METHODS: As measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms. RESULTS: We found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. CONCLUSIONS: Our data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and decreasing PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.

Bevacizumab plus erlotinib in Chinese patients with untreated, EGFR-mutated, advanced NSCLC (ARTEMIS-CTONG1509): A multicenter phase 3 study.

Dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) pathways may delay therapeutic resistance in advanced non-small cell lung cancer (NSCLC). This phase 3 study investigated the efficacy and safety of an erlotinib plus bevacizumab regimen in untreated patients with advanced NSCLC. In total, 311 patients received bevacizumab plus erlotinib (n = 157) or erlotinib only (n = 154). Progression-free survival (PFS) was 17.9 months (95% confidence interval [CI], 15.2-19.9) for bevacizumab plus erlotinib and 11.2 months (95% CI, 9.7-13.8) for erlotinib only (hazard ratio [HR] = 0.55; 95% CI, 0.41-0.73; p < 0.001). A brain metastases subgroup treated with bevacizumab plus erlotinib also showed improved PFS (HR = 0.48; 95% CI, 0.27-0.84; p = 0.008). Grade ≥3 treatment-related adverse events occurred in 86 (54.8%) and 40 (26.1%) patients, respectively. Bevacizumab plus erlotinib significantly improved PFS in patients with untreated metastatic EGFR-mutated NSCLC, including those with brain metastases at baseline.

Current Progress and Future Perspectives of Immune Checkpoint Inhibitors in Biliary Tract Cancer.

Biliary tract cancer (BTC) is an uncommon and aggressive neoplasm, with most patients presenting in an advanced stage. Systemic chemotherapy is the limited treatment available but is unsatisfactory, while targeted therapy is still awaiting validation from clinical trials. Given the potential effect of immune checkpoint inhibitors (ICIs) in the treatment of BTC, this review aims to summarize the evidence-based benefits and predictive biomarkers for using inhibitors of cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) ligand, or programmed cell death protein-1 and its ligand (PD-1 and PD-L1) as monotherapy or combined with other anti-tumor therapies, while also pointing out certain pitfalls with the use of ICIs which need to be addressed.

Efficacy, Safety, and Correlative Biomarkers of Toripalimab in Previously Treated Recurrent or Metastatic Nasopharyngeal Carcinoma: A Phase II Clinical Trial (POLARIS-02).

PURPOSE: As yet, no checkpoint inhibitor has been approved to treat nasopharyngeal carcinoma (NPC). This study was aimed to evaluate the antitumor activity, safety, and biomarkers of toripalimab, a new programmed death-1 (PD-1) inhibitor for recurrent or metastatic NPC (RM-NPC) refractory to standard chemotherapy. PATIENTS AND METHODS: In this single-arm, multicenter phase II study, patients with RM-NPC received 3 mg/kg toripalimab once every 2 weeks via intravenous infusion until confirmed disease progression or unacceptable toxicity. The primary end point was objective response rate (ORR). The secondary end points included safety, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). RESULTS: Among all 190 patients, the ORR was 20.5% with median DOR 12.8 months, median PFS 1.9 months, and median OS 17.4 months. Among 92 patients who failed at least two lines of systemic chemotherapy, the ORR was 23.9%. The ORRs were 27.1% and 19.4% in PD-L1+ and PD-L1- patients, respectively (P = .31). Patients with ≥ 50% decrease of plasma Epstein-Barr virus (EBV) DNA copy number on day 28 had significantly better ORR than those with < 50% decrease, 48.3% versus 5.7% (P = .0001). Tumor mutational burden had a median value of 0.95 muts/mega-base in the cohort and had no predictive value for response. Whole-exome sequencing results from 174 patients revealed that the patients with genomic amplification in 11q13 region or ETV6 genomic alterations had poor responses to toripalimab. CONCLUSION: The POLARIS-02 study demonstrated a manageable safety profile and durable clinical response of toripalimab in patients with chemorefractory metastatic NPC. An early decrease in plasma EBV DNA copy number correlated with favorable response.

A phase Ib study of the highly selective MET-TKI savolitinib plus gefitinib in patients with EGFR-mutated, MET-amplified advanced non-small-cell lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are recommended first-line treatments in EGFR-mutated (EGFRm) non-small-cell lung cancer (NSCLC). However, acquired resistance (e.g. MET amplification) is frequently observed. Savolitinib (volitinib, HMPL-504, AZD6094) is an oral, potent, and highly selective MET-TKI. In this phase Ib, open-label, multicenter study, we enrolled Chinese patients with EGFRm advanced NSCLC, whose disease progressed following prior EGFR-TKI treatment. In the safety run-in, patients received savolitinib 600 or 800 mg plus gefitinib 250 mg orally once daily, and dose-limiting toxicities were recorded. In the expansion phase, patients with MET amplification received savolitinib plus gefitinib. The primary endpoint was safety/tolerability. Secondary endpoints included antitumor activity. Thirteen patients were enrolled in the safety phase (median age 52 years, 46% female) and 51 enrolled in the expansion phase (median age 61 years, 67% female). No dose-limiting toxicities were reported in either dose group during the safety run-in. Adverse events of grade ≥ 3 in the safety run-in and expansion phases (n = 57) were reported in 21 (37%) patients. The most frequently reported adverse events (all grades) were: vomiting (n = 26, 46%), nausea (n = 23, 40%), increased aspartate aminotransferase (n = 22, 39%). Of four deaths, none were treatment-related. The objective response rates in EGFR T790M-negative, -positive, and -unknown patients were 52% (12/23), 9% (2/23), and 40% (2/5), respectively. Savolitinib 600 mg plus gefitinib 250 mg once daily had an acceptable safety profile and demonstrated promising antitumor activity in EGFRm, MET-amplified advanced NSCLC patients who had disease progression on EGFR-TKIs. NCT02374645, Date of registration: March 2nd 2015.

JP3, an antiangiogenic peptide, inhibits growth and metastasis of gastric cancer through TRIM25/SP1/MMP2 axis.

BACKGROUND: Gastric cancer (GC) is the most prevalent gastrointestinal tumor with an unfavorable clinical prognosis. GC patients are largely threatened owing to metastasis and drug resistance. Tumor angiogenesis plays an important role in the development of gastric cancer and is a challenge in the treatment of gastric cancer. METHODS: Mouse xenograft models were used for screening of therapeutic peptides on GC growth and metastasis. Routine laboratory experimental methods including conditional cell culture, tube formation assay, qRT-PCR, Western blotting, immunohistochemistry (IHC), ubiquitination assay, and immunofluorescence (IF) were used in mechanism investigation; protein docking analysis and coimmunoprecipitation (Co-IP) were used for prediction and confirmation of interactions between JP3/SP1 and TRIM25/MEK1/2. RESULTS: We identified an MMP2-targeted peptide JP3 that plays inhibiting roles in modulating growth and metastasis of GC in vivo and has no observable toxic side effects. JP3 reduced tumor microvessel density (MVD) in vivo and human umbilical vein endothelial cells (HUVECs) tube formation in vitro. Mechanistic studies revealed that JP3 reduces polyubiquitination-mediated degradation of TRIM25 by increasing the stability of TRIM25 through phosphorylating it at Ser12. TRIM25, as an E3 ubiquitin ligase, promoted the ubiquitin of SP1 at K610, further suppressed expression of MMP2 and inhibited angiogenesis in GC. Importantly, the inversely association between TRIM25 and SP1 protein level was further verified in human GC tissues. Decreased TRIM25 expression and increased SP1 expression in tumor tissues were positively correlated with poor prognosis of GC patients. CONCLUSIONS: MMP2-targeted peptide JP3 plays a therapeutic role in GC through anti-angiogenesis by modulating TRIM25/SP1/MMP2.

Association Of Initial Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Treatment And EGFR Exon 19 Deletion With Frequency Of The T790M Mutation In Non-Small Cell Lung Cancer Patients After Resistance To First-Line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

BACKGROUND: The present study analyzed the relationship between clinical features and the T790M mutation in non-small cell lung cancer (NSCLC) patients resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. METHODS: NSCLC patients with resistance to first-generation EGFR-TKIs in which the disease control time was more than 6 months after initial TKI treatment were enrolled. T790M mutation analysis was performed using one of the following methods according to each manufacturer's protocols: Cobas EGFR mutation test (41/105, 39.0%), digital PCR (42/105, 40.0%) or Scorpion amplification refractory mutation system (ARMS) (22/105, 21.0%). Sample type of T790M was from tissue only (53/105, 50.5%), plasma only (46/105, 43.8%), tissue and plasma (6/105, 5.7%). RESULTS: Of 105 patients, 57 were T790M-positive and 48 were T790M-negative. T790M-positive patients had longer progression-free survival (PFS) after initial EGFR-TKI treatment (p = 0.019). T790M positivity was more frequent in patients treated with gefitinib than in those treated with icotinib (65% vs 40.54%, p = 0.018). The rate of T790M positivity was lower in patients with EGFR L858R (44.44%, 12/27) before TKI treatment than in those with EGFR 19del (72.0%, 36/50, p = 0.036). Patients who achieved PR after initial EGFR-TKI treatment had a higher rate of T790M positivity than those with SD (75.76% vs 50%, p = 0.023). There was no relationship between T790M status and age, gender, primary site, metastasis site, or treatment before TKI. CONCLUSION: Progression-free survival (PFS), drug type, response to initial EGFR-TKI treatment, and EGFR status before initial EGFR treatment were associated with the frequency of T790M mutation.

KLF5 and MYC modulated LINC00346 contributes to gastric cancer progression through acting as a competing endogeous RNA and indicates poor outcome.

It was found in this study that long intergenic non-protein coding RNA 346 (LINC00346) was an lncRNA aberrantly expressed in gastric cancer (GC) based on multiple Gene Expression Omnibus (GEO) databases of GC cohorts. The LINC00346 gene was recurrently amplified and upregulated in GC, and its expression was positively correlated with poor pathologic stage, large tumor size, and poor prognosis. In addition, the oncogenic transcription factors KLF5 and MYC could bind to the LINC00346 promoter and enhance its expression. Gene Set Enrichment Analysis (GSEA) in the GEO datasets revealed that cell cycle and focal adhesion genes were enriched in patients with high LINC00346 expression. In vitro and in vivo assays of LINC00346 alterations revealed a complex integrated phenotype affecting cell growth, migration and invasion. Strikingly, high-throughput sequencing analysis after LINC00346 alterations highlighted alterations in cell cycle and focal adhesion pathways in GC cells. Mechanistically, argonaute 2 (Ago2) was recruited by LINC00346, which functioned as a molecular sponge for miR-34a-5p by antagonizing its ability to repress CD44, NOTCH1, and AXL protein translation. Taken together, our findings support a model in which the KLF5, MYC/LINC00346/miR-34a-5p cross-talk served as critical effectors in GC tumorigenesis and progression, suggesting a new therapeutic direction in the treatment of GC.

A meta-analysis of caspase-8 -652 6N del polymorphism and digestive tract cancer risk.

Caspase-8 (CASP8) is one key regulator of apoptosis of T lymphocytes and is encoded by the CASP8 gene. It has been reported that the six-nucleotide deletion polymorphism (-652 6N del) of the CASP8 gene had effect on some cancer risk. Few studies explored the association between CASP8 gene polymorphism and digestive tract cancer risk. To evaluate the association between the CASP8 -652 6N del polymorphism and the risk of digestive tract cancer, we conducted this meta-analysis. We found that CASP8-652 6N del polymorphism was associated with a significantly reduced risk of digestive tract cancer in the co-dominant model (del/del vs. ins/ins: OR= 0.82, 95%CI= 0.72-0.95; del/ins vs. ins/ins: OR= 0.92, 95%CI= 0.87-0.97; dominant model (del/ins+ del/del vs. ins/ins: OR= 0.91, 95%CI= 0.87-0.96, recessive model: del/del vs. del/ins+ ins/ins: OR= 0.85, 95%CI= 0.75-0.97). In the stratified analysis by cancer types, we found that all genetic models had protective effect on gastric cancer. Similar results were observed for colorectal cancer under heterozygote comparison and dominant model, but not under homozygote comparison or recessive model. In addition, a significantly decreased risk was found on esophageal cancer for most genetic models, except heterozygote comparison. When stratified by ethnicity and source of control, an evidently decreased risk was identified in the Asian populations and population-based studies. In conclusion, there exists an association between the CASP8 -652 6N del polymorphism and reduced digestive cancer risk, especially among Asians and population-based studies.

Upregulation of the long noncoding RNA FOXD2-AS1 promotes carcinogenesis by epigenetically silencing EphB3 through EZH2 and LSD1, and predicts poor prognosis in gastric cancer.

Accumulating data indicate that long noncoding RNAs (lncRNAs) serve as important modulators in biological processes and are dysregulated in diverse tumors. The function of FOXD2-AS1 in gastric cancer (GC) progression and related biological mechanisms remain undefined. A comprehensive analysis identified that FOXD2-AS1 enrichment was upregulated markedly in GC and positively correlated with a large tumor size, a later pathologic stage, and a poor prognosis. Gene-set enrichment analysis (GSEA) in GEO datasets uncovered that cell cycle and DNA replication associated genes were enriched in patients with high FOXD2-AS1 expression. Loss of FOXD2-AS1 function inhibited cell growth via inhibiting the cell cycle in GC, whereas upregulation of FOXD2-AS1 expression promoted cancer progression. The enhancer of zeste homolog 2 (EZH2) and lysine (K)-specific demethylase 1A (LSD1) proteins were found to serve as binding partners of FOXD2-AS1 and mediators of FOXD2-AS1 function. Mechanically, FOXD2-AS1 promoted GC tumorigenesis partly through EZH2 and LSD1 mediated EphB3 downregulation. The present results revealed that FOXD2-AS1 acted as a tumor inducer in GC partly through EphB3 inhibition by direct interaction with EZH2 and LSD1, and may prove to be a potential biomarker of carcinogenesis.

HOX transcript antisense intergenic RNA represses E-cadherin expression by binding to EZH2 in gastric cancer.

AIM: To clarify the mechanisms of HOX transcript antisense intergenic RNA (HOTAIR) in gastric cancer (GC) migration and invasion. METHODS: Quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression level of HOTAIR in GC tissues. The correlation of its expression with clinicopathological features was analyzed. Area under receiver operating characteristic curve (AUCROC) was constructed to evaluate the diagnostic value of HOTAIR. Wound-healing assay and Transwell assay were performed to detect the biological effects of HOTAIR in GC cells. qPCR, western blot and immunohistochemistry were used to evaluate the mRNA and protein expression of E-cadherin. RNA-binding protein immunoprecipitation was used for the analysis of EZH2 interactions with HOTAIR. Chromatin immunoprecipitation assay was performed to investigate direct interactions between EZH2 and E-cadherin. RESULTS: The expression of HOTAIR was up-regulated in GC tumorous tissues compared with the para-tumorous tissues (P < 0.001). Its over-expression was correlated with tumor-node-metastasis (TNM) stage (P = 0.024), tumor invasion (P = 0.018), lymph node metastasis (P = 0.023), and poor prognosis (P < 0.001). Multivariate Cox regression analysis confirmed expression of HOTAIR as an independent predictor of overall survival (P = 0.033), together with TNM stage (P = 0.002) and lymph node metastasis (P = 0.002). The AUCROC was up to 0.709 (95%CI: 0.623-0.785, P < 0.001). Knockdown of HOTAIR by siRNA in GC cells suppressed the migration and invasion of GC cells. Significantly negative correlation between HOTAIR and E-cadherin was found in GC tissues and cell lines, and HOTAIR contributed to the regulation of E-cadherin through binding to EZH2 with the E-cadherin promoter. CONCLUSION: HOTAIR may play a pivotal role in tumor cell migration and invasion. It can be used as a potential diagnostic and prognostic biomarker for GC.

Taurine­upregulated gene 1: A vital long non­coding RNA associated with cancer in humans (Review).

It is widely reported that long non­coding RNAs (lncRNAs) are involved in regulating cell differentiation, proliferation, apoptosis and other biological processes. Certain lncRNAs have been found to be crucial in various types of tumor. Taurine­upregulated gene 1 (TUG1) has been shown to be expressed in a tissue­specific pattern and exert oncogenic or tumor suppressive functions in different types of cancer in humans. According to previous studies, TUG1 is predominantly located in the nucleus and may regulate gene expression at the transcriptional level. It mediates chromosomal remodeling and coordinates with polycomb repressive complex 2 (PRC2) to regulate gene expression. Although the mechanisms of how TUG1 affects the tumor genesis process remain to be fully elucidated, increasing studies have suggested that TUG1 offers potential as a diagnostic and prognostic biomarker, and as a therapeutic target in certain types of tumor. This review aims to summarize current evidence concerning the characteristics, mechanisms and associations with cancer of TUG1.

KLF16 promotes proliferation in gastric cancer cells via regulating p21 and CDK4.

Krüppel-like factors (KLFs), such as KLF4, KLF2, KLF5 and KLF15, have been extensively investigated in multi-cancers. However, KLF16, a member of KLFs, hasn't been well identified in cancer, especially in gastric cancer (GC). Here, we investigated the roles of KLF16 in GC. In present study, we found that KLF16 expression levels were significantly up-regulated in GC tissues compared to adjacent normal tissues both in protein and mRNA levels by using immunohistochemistry assays (IHC) and real-time quantitative PCR (qPCR). And KLF16 expression levels were positively correlated to tumor size, invasion depth, lymphatic metastasis and TNM stage. Furthermore, KLF16 expression also could predict prognosis in patients with GC. Moreover, the knock-down of KLF16 could significantly suppress proliferation via increasing p21 expression and decreasing CDK4 expression in GC cell lines. In summary, these findings demonstrate that KLF16 plays a significant role in GC progression and could be a new therapeutic target for GC patients.

E2F1 induces TINCR transcriptional activity and accelerates gastric cancer progression via activation of TINCR/STAU1/CDKN2B signaling axis.

Recent evidence indicates that E2F1 transcription factor have pivotal roles in the regulation of cellular processes, and is found to be dysregulated in a variety of cancers. Long non-coding RNAs (lncRNAs) are also reported to exert important effect on tumorigenesis. E2F1 is aberrantly expressed in gastric cancer (GC), and biology functions of E2F1 in GC are controversial. The biological characteristics of E2F1 and correlation between E2F1 and lncRNAs in GC remain to be found. In this study, integrated analysis revealed that E2F1 expression was significantly increased in GC cases and its expression was positively correlated with the poor pathologic stage, large tumor size and poor prognosis. Forced E2F1 expression promotes proliferation, whereas loss of E2F1 function decreased cell proliferation by blocking of cell cycle in GC cells. Mechanistic analyses indicated that E2F1 accelerates GC growth partly through induces TINCR transcription. TINCR could bind to STAU1 (staufen1) protein, and influence CDKN2B mRNA stability and expression, thereby affecting the proliferation of GC cells. Together, our findings suggest that E2F1/TINCR/STAU1/CDKN2B signaling axis contributes to the oncogenic potential of GC and may constitute a potential therapeutic target in this disease.

MicroRNA-30e reduces cell growth and enhances drug sensitivity to gefitinib in lung carcinoma.

MicroRNAs (miRNAs) play critical roles in variousbiological processes,including malignancy. Here, we demonstrated that miR-30e levels were markedly reduced in human lung carcinoma specimens in comparisonwith adjacent normal tissues.In addition, miR-30eamounts were starkly lower in the resistant PC9/gefitinib (PC9G) cancer cells compared with PC9 cells. Meanwhile, miR-30eoverexpression inPC9G cells resulted in reduced cell proliferation and migration,reversing drug resistance to gefitinib.Conversely,miR-30e silencing in PC9 cells increased proliferation as well as migration, and conferred resistance to gefitinib.Moreover, HOXA1, which was identified asa new miR-30etarget, plays important roles in regulating cell fate, early developmental patterns and organogenesis.Importantly, miR-30ealso inhibited PC9G growth in vivo. Taken together, these findings demonstrated that miR-30eshould be considered a tumor suppressor miRNA, which could be used in treatinghuman lung cancer.