Xiaoliang Wu

Long noncoding RNA XIST promotes malignancies of esophageal squamous cell carcinoma via regulation of miR-101/EZH2

The long non-coding RNA XIST is a long non-coding RNA that associates with polycomb repressive complex 2 to regulate X-chromosome inactivation in female mammals. The biological roles as well as the underlying mechanisms of XIST in esophageal squamous cell carcinoma remained yet to be solved. Our data indicated that XIST was significantly upregulated in esophageal squamous cancerous tissues and cancer cell lines, as compared with that in the corresponding non-cancerous tissues and immortalized normal squamous epithelial cells. High XIST expression predicted poor prognosis of esophageal squamous cancer patients. Lentivirus mediated knockdown of XIST inhibited proliferation, migration and invasion of esophageal squamous cancer cells in vitro and suppressed tumor growth in vivo. Knockdown of XIST resulted in elevated expression of miR-101 and decreased expression of EZH2. Further analysis showed that XIST functioned as the competitive endogenous RNA of miR-101 to regulate EZH2 expression. Moreover, enforced expression of EZH2 significantly attenuated the anti-proliferation activity upon XIST knockdown. Conclusively, XIST plays an important role in malignant progression of ESCC via modulation of miR-101/EZH2 axis.The long non-coding RNA XIST is a long non-coding RNA that associates with polycomb repressive complex 2 to regulate X-chromosome inactivation in female mammals. The biological roles as well as the underlying mechanisms of XIST in esophageal squamous cell carcinoma remained yet to be solved. Our data indicated that XIST was significantly upregulated in esophageal squamous cancerous tissues and cancer cell lines, as compared with that in the corresponding non-cancerous tissues and immortalized normal squamous epithelial cells. High XIST expression predicted poor prognosis of esophageal squamous cancer patients. Lentivirus mediated knockdown of XIST inhibited proliferation, migration and invasion of esophageal squamous cancer cells in vitro and suppressed tumor growth in vivo. Knockdown of XIST resulted in elevated expression of miR-101 and decreased expression of EZH2. Further analysis showed that XIST functioned as the competitive endogenous RNA of miR-101 to regulate EZH2 expression. Moreover, enforced expression of EZH2 significantly attenuated the anti-proliferation activity upon XIST knockdown. Conclusively, XIST plays an important role in malignant progression of ESCC via modulation of miR-101/EZH2 axis.

Long non-coding RNA ATB promotes malignancy of esophageal squamous cell carcinoma by regulating miR-200b/Kindlin-2 axis

Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of cancer-related death, especially in China. In addition, the prognosis of late stage patients is extremely poor. However, the biological significance of the long non-coding RNA lnc-ATB and its potential role in ESCC remain to be documented. In this study, we investigated the role of lnc-ATB and the underlying mechanism promoting its oncogenic activity in ESCC. Expression of lnc-ATB was higher in ESCC tissues and cell lines than that in normal counterparts. Upregulated lnc-ATB served as an independent prognosis predictor of ESCC patients. Moreover, loss-of-function assays in ESCC cells showed that knockdown of lnc-ATB inhibited cell proliferation and migration both in vitro and in vivo. Mechanistic investigation indicated that lnc-ATB exerted oncogenic activities via regulating Kindlin-2, as the anti-migration role of lnc-ATB silence was attenuated by ectopic expression of Kindlin-2. Further analysis showed that lnc-ATB functions as a molecular sponge for miR-200b and Kindlin-2. Dysregulated miR-200b/Kindlin-2 signaling mediated the oncogenic activity of lnc-ATB in ESCC. Our results suggest that lnc-ATB predicts poor prognosis and may serve as a potential therapeutic target for ESCC patients.

NORAD Expression Is Associated with Adverse Prognosis in Esophageal Squamous Cell Carcinoma

Background: NORAD (non-coding RNA-activated by DNA damage) is a conserved, abundant, and broadly expressed long non-coding RNA, which functions to preserve genome stability. However, its prognostic significance in esophageal squamous cell carcinoma (ESCC) remains unclear. Material and Methods: The expression of NORAD was detected by quantitative real-time polymerase chain reaction in pairs of tumorous and adjacent normal tissues derived from 106 ESCC patients. We analyzed the potential relationship between NORAD expression levels in tumor tissues and clinicopathological features of ESCC patients and clinical outcome. Results: The relative expression levels of NORAD were significantly upregulated in tumor tissues (p < 0.001) compared to adjacent normal tissues. In addition, high expression of NORAD was correlated with larger tumor size (p = 0.021) and T stage (p = 0.045). Kaplan-Meier analysis indicated that patients with high NORAD expression had poor overall and disease-free survival (p < 0.001). Moreover, multivariate analysis showed that increased expression of NORAD was an independent predictor of overall survival (p = 0.001). Conclusion: Our data indicate that increased NORAD expression might serve as a novel molecular predictor of poor prognosis in ESCC patients and maybe a potential target for diagnosis and gene therapy.

AXL–GAS6 expression can predict for adverse prognosis in non-small cell lung cancer with brain metastases

PurposePatients with non-small cell lung cancer (NSCLC) brain metastases (BM) have poor clinical outcomes. We sought to determine if AXL–GAS6 expression can be used as independent prognostic biomarkers for NSCLC BM.MethodsWe retrospectively studied the medical records of 98 patients diagnosed with advanced metastatic NSCLC from December 2000 to June 2014. Out of a total of 98 patients with NSCLC metastases, 66 patients were identified to have brain metastases. The expressions of AXL and GAS6 were assessed by standard immunohistochemistry and correlated with clinicopathological factors and overall survival (OS) outcomes.ResultsThe expression of AXL was positively associated with GAS6 expression (P < 0.001), and tumor differentiation (P = 0.014) in advanced NSCLC with metastases. AXL expression displayed no association with gender, age, smoking history, pathology, T stage, N stage, CEA, and LDH. In univariate analysis, both AXL and GAS6 were found to predict worse OS outcomes (AXL: HR 1.77, 95% CI 1.13–2.79, P = 0.01; GAS6: HR 1.80, 95% CI 1.14–2.84, P = 0.01). In the brain metastasis subgroup, the expression of AXL was positively associated with GAS6 expression (P < 0.001). Both AXL and GAS6 were found to predict worse BM-OS outcomes in univariate analysis (AXL: HR 2.19, 95% CI 1.33–4.10, P = 0.005; GAS6: HR 2.04, 95% CI 1.01–3.71, P = 0.019). In multivariate analysis, high co-expression of AXL/GAS6 was found to be an independent unfavorable risk factor for the overall study population (HR 2.33, 95% CI 1.40–3.87, P = 0.0011) and also in BM (HR 2.76, 95% CI 1.45–5.25, P = 0.001), predicting worse survival outcome.ConclusionsAXL–GAS6 co-expression represents a potential independent prognostic biomarker for survival outcome in NSCLC BM patients.

The application and mechanism of PD pathway blockade for cancer therapy

Research in cancer therapeutics has achieved major progress in the understanding of the tumour-immunity cycle, which controls the delicate balance between the immune system and tumour. Identification of cancer cell T-cell inhibitory signals, including PD-L1, has generated novel insight into how to reinvigorate the patients’ immune cells to respond to a variety of tumour types. PD-1 and PD-L1 (PD) inhibitory pathway blockade appears to a highly promising therapy and could accomplish durable anti-tumour responses with a reasonable toxicity profile. Some of the FDA-approved mAbs can reverse the negative regulators from tumour cells and antigen presenting cells of T-cell function to treat some cancer types by blocking the PD signalling pathway,especially advanced solid tumours. Emerging clinical data suggest that cancer immunotherapy will become a significant part of the clinical treatment of cancer.

Transcriptomic-metabolomic reprogramming in EGFR-mutant NSCLC early adaptive drug escape linking TGFβ2-bioenergetics-mitochondrial priming

The impact of EGFR-mutant NSCLC precision therapy is limited by acquired resistance despite initial excellent response. Classic studies of EGFR-mutant clinical resistance to precision therapy were based on tumor rebiopsies late during clinical tumor progression on therapy. Here, we characterized a novel non-mutational early adaptive drug-escape in EGFR-mutant lung tumor cells only days after therapy initiation, that is MET-independent. The drug-escape cell states were analyzed by integrated transcriptomic and metabolomics profiling uncovering a central role for autocrine TGFβ2 in mediating cellular plasticity through profound cellular adaptive Omics reprogramming, with common mechanistic link to prosurvival mitochondrial priming. Cells undergoing early adaptive drug escape are in proliferative-metabolic quiescent, with enhanced EMT-ness and stem cell signaling, exhibiting global bioenergetics suppression including reverse Warburg, and are susceptible to glutamine deprivation and TGFβ2 inhibition. Our study further supports a preemptive therapeutic targeting of bioenergetics and mitochondrial priming to impact early drug-escape emergence using EGFR precision inhibitor combined with broad BH3-mimetic to interrupt BCL-2/BCL-xL together, but not BCL-2 alone.

Abstract 3874: Mass spectrometry imaging determines biomarkers of early adaptive precision drug resistance in lung cancer

Drug resistance emergence is a common problem that limits long term outcome benefits in the era of precision cancer therapy. Recently, we identified an early precision drug escape mechanism with adaptive tumor cellular reprogramming emerging within days after drug initiation. Here we present a mass spectrometry imaging (MSI) approach to interrogate the biomolecular changes occurring within residual tumor cells under precision treatment with an ALK-specific kinase inhibitor TAE684 in EML4-ALK fusion (ALK+) lung adenocarcinoma xenograft. ALK+ H3122 lung adenocarcinoma murine xenograft model was established for in vivo treatment with TAE684, at a daily dose of 25mg/kg by orogastric gavage (n = 6). Diluent control was included as comparison (n = 6). Tumor measurement revealed expected remarkable tumor response with TAE684. Control tumors and drug-treated residual tumor tissues were harvested for MSI studies, at day 7 and day 14 during tumor response. MSI was carried out on formalin fixed, paraffin embedded tissues to compare peptide profiles between control tumors and 7- and 14-day ALK-TKI treated tumors using a histology guided mass spectrometry approach. Briefly, two sections were collected from each sample, one for mass spectrometry and one for histology. Mass spectrometry sections were deparaffinized, antigen retrieved, and subjected to on-tissue tryptic digestion. Tumoral areas of interest (100 μm diameter, ∼20 per sample) were annotated on digital microscopy images of the stained sections. The annotated images were merged with digital images of the unstained sections using Photoshop and this combined image was used to guide data acquisition from the areas of interest. Additionally, frozen control and day 14 TAE684 treated tumors were subjected to full section MSI to determine the ALK inhibitor drug distribution as well as the changing landscape of lipids and metabolites. Statistical analysis of the peptide data resulted in determination of 580 significant peaks using Wilcoxon rank sum test with a Bonferroni correction. A genetic algorithm classification model consisting of 24 peptide peaks was generated using a leave-20%-out cross validation over 10 iterations that resulted in an overall classification accuracy across the 3 groups of over 98%. Direct MS/MS fragmentation revealed that TAE684 was detected within the frozen dosed tumors, but was absent from the control tumors. Several lipids (notably, m/z 732.78, 744.67, and 770.72 increased, m/z 769.65 and 820.71 decreased) were found to undergo alterations in expression as a result of TAE684 treatment. MSI allowed for the direct in situ determination of biomolecules that are changing in expression landscape in ALK+ lung cancer as a result of TAE684 treatment. These results provide a rationale to advance our MSI studies to deepen our insights in mechanisms of adaptive precision drug resistance to improve treatment outcomes. Citation Format: Erin H. Seeley, Pamela S. Cantrell, Callee M. Walsh, Sijin Wen, Satoshi Komo, Xiaoliang Wu, Wei Zhang, Patrick C. Ma. Mass spectrometry imaging determines biomarkers of early adaptive precision drug resistance in lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3874.