lncRNA DIRC3 regulates invasiveness and insulin-like growth factor signaling in thyroid cancer cells.

Differentiated thyroid cancers (DTCs) are malignancies that demonstrate strong but largely uncharacterized heritability. Germline variants that influence the risk of DTCs localize in disrupted in renal carcinoma 3 (DIRC3), a poorly described long non-coding RNA gene. Here, we investigated the function of DIRC3 in DTCs. Using patient-matched thyroid tissue pairs and The Cancer Genome Atlas data, we established that DIRC3 is downregulated in DTCs, whereas high expression of DIRC3 in tumors may reduce the risk of cancer recurrence. DIRC3 transcripts were enriched in cell nuclei, where they upregulated insulin-like growth factor binding protein 5 (IGFBP5), a gene that modulates the cellular response to insulin-like growth factor 1 (IGF1). Silencing DIRC3 in thyroid cancer cell lines (MDA-T32 and MDA-T120) had a dichotomous phenotypic influence: augmented cell migration and invasiveness, reduced apoptosis, but abrogated the MTT reduction rate. Transcriptomic profiling and gene rescue experiments indicated the functional redundancy in the activities of DIRC3 and IGFBP5. Moreover, the reduced level of DIRC3 enhanced the susceptibility of thyroid cancer cells to IGF1 stimulation and promoted Akt signaling via downregulation of the IGFBP5 protein. In conclusion, DIRC3 expression alters the phenotype of thyroid cancer cells and regulates the activity of the IGFBP5/IGF1/Akt axis. Our findings suggest that an interplay between DIRC3 and IGF signaling may play a role in promoting thyroid carcinogenesis.

A comprehensive review on posttreatment surveillance in colorectal patients.

Patients who undergo a potentially curative treatment of colorectal cancer are at risk of local recurrences, distant metastases, and metachronous neoplasms. Accordingly, these patients typically undergo a multimodal oncological surveillance aimed to detect relapses early, with an expectation of a higher rate of radical retreatments and better overall survival. Despite much research, the optimal diagnostic panel and the intensity of surveillance have not been well established. Evidence indicates, however, that more intensive follow­up is unlikely to improve survival after a curative colorectal cancer surgery, chiefly due to the scarcity of recurrences suitable for salvage treatment. Typical surveillance recommended by guidelines includes regular physical examinations, computed tomography scans, serum carcinoembryonic antigen monitoring, and colonoscopy. The objective of this comprehensive review is to discuss different patterns of relapses observed in colorectal cancer patients, present diagnostic options, and summarize different strategies and recommendations of the posttreatment surveillance.

Discovery and development of differentially methylated regions in human papillomavirus-related oropharyngeal squamous cell carcinoma.

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) exhibits a different composition of epigenetic alterations. In this study, we identified differentially methylated regions (DMRs) with potential utility in screening for HPV-positive OPSCC. Genome wide DNA methylation was measured using methyl-CpG binding domain protein-enriched genome sequencing (MBD-seq) in 50 HPV-positive OPSCC tissues and 25 normal tissues. Fifty-one DMRs were defined with maximal methylation specificity to cancer samples. The Cancer Genome Atlas (TCGA) methylation array data was used to evaluate the performance of the proposed candidates. Supervised hierarchical clustering of 51 DMRs found that HPV-positive OPSCC had significantly higher DNA methylation levels compared to normal samples, and non-HPV-related head and neck squamous cell carcinoma (HNSCC). The methylation levels of all top 20 DNA methylation biomarkers in HPV-positive OPSCC were significantly higher than those in normal samples. Further confirmation using quantitative methylation specific PCR (QMSP) in an independent set of 24 HPV-related OPSCCs and 22 controls showed that 16 of the 20 candidates had significant higher methylation levels in HPV-positive OPSCC samples compared with controls. One candidate, OR6S1, had a sensitivity of 100%, while 17 candidates (KCNA3, EMBP1, CCDC181, DPP4, ITGA4, BEND4, ELMO1, SFMBT2, C1QL3, MIR129-2, NID2, HOXB4, ZNF439, ZNF93, VSTM2B, ZNF137P and ZNF773) had specificities of 100%. The prediction accuracy of the 20 candidates rang from 56.2% to 99.8% by receiver operating characteristic analysis. We have defined 20 highly specific DMRs in HPV-related OPSCC, which can potentially be applied to molecular-based detection tests and improve disease management.

Bifunctional immune checkpoint-targeted antibody-ligand traps that simultaneously disable TGFß enhance the efficacy of cancer immunotherapy.

A majority of cancers fail to respond to immunotherapy with antibodies targeting immune checkpoints, such as cytotoxic T-lymphocyte antigen-4 (CTLA-4) or programmed death-1 (PD-1)/PD-1 ligand (PD-L1). Cancers frequently express transforming growth factor-ß (TGFß), which drives immune dysfunction in the tumor microenvironment by inducing regulatory T cells (Tregs) and inhibiting CD8+ and TH1 cells. To address this therapeutic challenge, we invent bifunctional antibody-ligand traps (Y-traps) comprising an antibody targeting CTLA-4 or PD-L1 fused to a TGFß receptor II ectodomain sequence that simultaneously disables autocrine/paracrine TGFß in the target cell microenvironment (a-CTLA4-TGFßRIIecd and a-PDL1-TGFßRIIecd). a-CTLA4-TGFßRIIecd is more effective in reducing tumor-infiltrating Tregs and inhibiting tumor progression compared with CTLA-4 antibody (Ipilimumab). Likewise, a-PDL1-TGFßRIIecd exhibits superior antitumor efficacy compared with PD-L1 antibodies (Atezolizumab or Avelumab). Our data demonstrate that Y-traps counteract TGFß-mediated differentiation of Tregs and immune tolerance, thereby providing a potentially more effective immunotherapeutic strategy against cancers that are resistant to current immune checkpoint inhibitors.

Comparative mutational landscape analysis of patient-derived tumour xenografts.

BACKGROUND: Screening of patients for cancer-driving mutations is now used for cancer prognosis, remission scoring and treatment selection. Although recently emerged targeted next-generation sequencing-based approaches offer promising diagnostic capabilities, there are still limitations. There is a pressing clinical need for a well-validated, rapid, cost-effective mutation profiling system in patient specimens. Given their speed and cost-effectiveness, quantitative PCR mutation detection techniques are well suited for the clinical environment. The qBiomarker mutation PCR array has high sensitivity and shorter turnaround times compared with other methods. However, a direct comparison with existing viable alternatives are required to assess its true potential and limitations. METHODS: In this study, we evaluated a panel of 117 patient-derived tumour xenografts by the qBiomarker array and compared with other methods for mutation detection, including Ion AmpliSeq sequencing, whole-exome sequencing and droplet digital PCR. RESULTS: Our broad analysis demonstrates that the qBiomarker's performance is on par with that of other labour-intensive and expensive methods of cancer mutation detection of frequently altered cancer-associated genes, and provides a foundation for supporting its consideration as an option for molecular diagnostics. CONCLUSIONS: This large-scale direct comparison and validation of currently available mutation detection approaches is extremely relevant for the current scenario of precision medicine and will lead to informed choice of screening methodologies, especially in lower budget conditions or time frame limitations.

Adenoid cystic carcinoma: emerging role of translocations and gene fusions.

Adenoid cystic carcinoma (ACC), the second most common salivary gland malignancy, is notorious for poor prognosis, which reflects the propensity of ACC to progress to clinically advanced metastatic disease. Due to high long-term mortality and lack of effective systemic treatment, the slow-growing but aggressive ACC poses a particular challenge in head and neck oncology. Despite the advancements in cancer genomics, up until recently relatively few genetic alterations critical to the ACC development have been recognized. Although the specific chromosomal translocations resulting in MYB-NFIB fusions provide insight into the ACC pathogenesis and represent attractive diagnostic and therapeutic targets, their clinical significance is unclear, and a substantial subset of ACCs do not harbor the MYB-NFIB translocation. Strategies based on detection of newly described genetic events (such as MYB activating super-enhancer translocations and alterations affecting another member of MYB transcription factor family-MYBL1) offer new hope for improved risk assessment, therapeutic intervention and tumor surveillance. However, the impact of these approaches is still limited by an incomplete understanding of the ACC biology, and the manner by which these alterations initiate and drive ACC remains to be delineated. This manuscript summarizes the current status of gene fusions and other driver genetic alterations in ACC pathogenesis and discusses new therapeutic strategies stemming from the current research.

Common pathway signature in lung and liver fibrosis.

Fibrosis, a progressive accumulation of extracellular matrix components, encompasses a wide spectrum of distinct organs, and accounts for an increasing burden of morbidity and mortality worldwide. Despite the tremendous clinical impact, the mechanisms governing the fibrotic process are not yet understood, and to date, no clinically reliable therapies for fibrosis have been discovered. Here we applied Regeneration Intelligence, a new bioinformatics software suite for qualitative analysis of intracellular signaling pathway activation using transcriptomic data, to assess a network of molecular signaling in lung and liver fibrosis. In both tissues, our analysis detected major conserved signaling pathways strongly associated with fibrosis, suggesting that some of the pathways identified by our algorithm but not yet wet-lab validated as fibrogenesis related, may be attractive targets for future research. While the majority of significantly disrupted pathways were specific to histologically distinct organs, several pathways have been concurrently activated or downregulated among the hepatic and pulmonary fibrosis samples, providing new evidence of evolutionary conserved pathways that may be relevant as possible therapeutic targets. While future confirmatory studies are warranted to validate these observations, our platform proposes a promising new approach for detecting fibrosis-promoting pathways and tailoring the right therapy to prevent fibrogenesis.

Epigenetic silencing of S100A2 in bladder and head and neck cancers.

S100A2, a member of the S100 protein family, is known to be downregulated in a number of human cancers, leading to its designation as a potential tumor suppressor gene. Here, we investigated the expression and methylation status of S100A2 in head&neck and bladder cancer. Reduced mRNA and protein expression was observed in 8 head&neck and bladder cancer cell lines. To explore the mechanism responsible for the downregulation of S100A2, we treated six cell lines with 5-aza-2'-deoxycytidine. We found S100A2 is silenced in association with aberrant promoter-region methylation and its expression is restored with 5-aza-2'-deoxycytidine treatment. Of 31 primary head&neck cancer cases and 31 bladder cancer cases, promoter methylation was detected in 90% and 80% of cases, respectively. Interestingly, only 1/9 of normal head&neck tissues and 2/6 of normal bladder tissues showed promoter methylation. S100A2 promoter methylation can be detected in urine and is more frequent in bladder cancer patients than in healthy subjects (96% vs 48% respectively). Moreover, increased methylation of S100A2 is linked to the progression of the tumor in bladder cancer (p<0.01). Together, this data shows that methylation-associated inactivation of S100A2 is frequent and may be an important event in the tumorigenesis of head&neck and bladder cancer.