Murine double minute 2 predicts response of advanced esophageal squamous cell carcinoma to definitive chemoradiotherapy

The Impact of the Ubiquitin System in the Pathogenesis of Squamous Cell Carcinomas

The ubiquitin system is a dynamic regulatory pathway controlling the activity, subcellular localization and stability of a myriad of cellular proteins, which in turn affects cellular homeostasis through the regulation of a variety of signaling cascades. Aberrant activity of key components of the ubiquitin system has been functionally linked with numerous human diseases including the initiation and progression of human tumors. In this review, we will contextualize the importance of the two main components of the ubiquitin system, the E3 ubiquitin ligases (E3s) and deubiquitinating enzymes (DUBs), in the etiology of squamous cell carcinomas (SCCs). We will discuss the signaling pathways regulated by these enzymes, emphasizing the genetic and molecular determinants underlying their deregulation in SCCs.

FGF5 methylation is a sensitivity marker of esophageal squamous cell carcinoma to definitive chemoradiotherapy

Definitive chemoradiotherapy (dCRT) is the major treatment for esophageal squamous cell carcinoma (ESCC), and prediction of the response to dCRT is important so as not to miss an opportunity to cure an ESCC. Nevertheless, few validated markers are available. Here, we aimed to identify a highly reproducible marker using multi-layer omics analysis. 117 ESCC samples from 67 responders and 50 non-responders were divided into screening, validation, and re-validation sets. In the screening cohort (n = 41), somatic mutations in 114 genes showed no association with dCRT response. Genome-wide DNA methylation analysis using Infinium HumanMethylation450 BeadChip array identified four genic regions significantly associated with dCRT response. Among them, FGF5 methylation was validated to be associated with dCRT response (n = 34; P = 0.001), and further re-validated (n = 42; P = 0.020) by bisulfite-pyrosequencing. The sensitivity and specificity in the combined validation and re-validation sets (n = 76) were 45% and 90%, respectively, by using the cut-off value established in the screening set, and FGF5 methylation had predictive power independent from clinicopathological parameters. In ESCC cell lines, FGF5 promoter methylation repressed its expression. FGF5 expression was induced by cisplatin (CDDP) treatment in three unmethylated cell lines, but not in two methylated cell lines. Exogenous FGF5 overexpression in a cell line with its methylation conferred resistance to CDDP. In non-cancerous esophageal tissues, FGF5 was not expressed, and its methylation was present in a small fraction of cells. These results showed that FGF5 methylation is a validated marker for ESCC sensitivity to dCRT.

Resistance of human primary mesenchymal stem cells to cytotoxic effects of nutlin-3 in vitro

BACKGROUND

The small-molecule nutlin-3 was found to be an effective therapeutic compound and p53 activator, and acts as a murine double minute 2 antagonist, although these findings need to be clinically confirmed. The essential components of the bone marrow include mesenchymal stem cells (MSCs), which play a key role in protecting, regenerating, and proliferating hematopoietic stem cells (HSCs). This feature is vital for HSC after exposure to myelotoxic anticancer agents; nevertheless, the effects of nutlin-3 on MSCs remain to be disclosed. The present research study was conducted to examine the antiproliferative and proapoptotic effectiveness of nutlin-3 in bone marrow MSCs (BMSCs).

MATERIALS AND METHODS

Human-derived BMSCs were cultured for different durations, that is, 24, 48, and 72 hours, and treated using various concentrations of nutlin-3, including 5, 10, 25, 50, and 100 μΜ. To investigate the effect of nutlin-3 on the apoptosis, cell vitality and proliferation in BMSCs, the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), thiazolyl blue tetrazolium bromide, propidium iodide (PI) and annexin V assay, as well as real-time polymerase chain reaction, were used.

RESULTS

BMSCs viability significantly decreased (P < .05) in the cells treated at concentrations of 50 and 100 μM for 24 hours and concentrations of 25, 50, and 100 μM for 48 hours and at all concentrations for 72 hours. The apoptosis of BMSCs (TUNEL positive) was significantly more visible at concentrations of 25 and 50 μM compared with that in the controls (P < .05), while this increased through dose-dependent processes. Annexin V/PI staining revealed negligible dose-dependent increases in all the apoptotic cells after 72 hours of incubation, and this apoptosis elevation was significant at 25 and 50 μM (P < .05).

CONCLUSION

Resistance to nutlin-3 was observed in human bone marrow-derived MSCs; nevertheless, further clinical data are required to be obtained with long-duration exposure to confirm the present findings.

Identification of serum biomarkers of chemoradiosensitivity in esophageal cancer via the targeted metabolomics approach

AIM

To identify the serum metabolomics signature that is correlated with the chemoradiosensitivity of esophageal squamous cell carcinoma (ESCC).

MATERIALS & METHODS

Untargeted and targeted metabolomics analysis of serum samples from 26 ESCC patients, which were collected before the neoadjuvant chemoradiotherapy, was performed.

RESULTS

On receiving the results of untargeted metabolomics analysis, we performed the targeted metabolomics analysis of the six metabolites (arabitol, betaine, glycine, L-serine, L-arginine and L-aspartate). The serum levels of the four metabolites (arabitol, glycine, L-serine and L-arginine) were significantly lower in the patients who achieved pathological complete response with neoadjuvant chemoradiotherapy compared with the patients who did not achieve pathological complete response (p = 0.0086, 0.0345, 0.0106 and 0.0373, respectively).

CONCLUSION

The serum levels of metabolites might be useful for predicting the chemoradiosensitivity of ESCC patients.

Residual carcinoma cells after chemoradiotherapy for esophageal squamous cell carcinoma patients: striving toward appropriate judgment of biopsy

In esophageal squamous cell carcinoma (ESCC) patients who are treated with chemoradiotherapy (CRT), identification of the presence or absence of residual or recurrent carcinoma is usually pivotal in their clinical management. In addition, the extent of carcinoma invasion into the esophageal wall could determine the clinical outcome of these patients following CRT. Therefore, in this study, we evaluated the response to CRT both macroscopically and histologically in a consecutive series of 42 ESCC patients receiving neoadjuvant chemoradiotherapy following curative esophageal resection at Tohoku University Hospital between August 2011 and December 2012. The histological grading of tumor regression was as follows: grade 3, markedly effective (no viable residual tumor cells); grade 2, moderately effective (residual tumor cells in less than one-third of the tumor); grade 1, slightly effective (1b, residual tumor cells in one-third to two-thirds of the tumor; 1a, residual tumor cells in more than two-thirds of the tumor); and grade 0, ineffective. In this study, we selected grade 2 and 1b cases because they might show a complete response with definitive CRT. We evaluated the presence of any residual in situ lesions and tumor depth in detail. The grading of tumor regression in primary sites was as follows: grade 3 (7 cases), grade 2 (16 cases), grade 1b (13 cases), and grade 1a (6 cases). The concordance rate between macroscopic and histopathological evaluation on the depth of the tumor was 40% (17/42). Among 29 cases (grade 2 and grade 1b), intraepithelial lesions were not detected in 17 cases, and tumor nests were not detected in the lamina propria mucosae in 9 cases. The results of this study highlight the difficulties of detecting residual carcinoma cells using conventional endoscopic biopsy in patients who have received CRT. Therefore, when residual cancer is clinically suspected in patients who have received CRT, the biopsy specimen should be obtained from the deep layer of the esophagus whenever possible. Additionally, close follow-up is required using positron emission tomography/computed tomography, endoscopy, and other radiological evaluations.

Novel Candidate Biomarkers of Chemoradiosensitivity in Esophageal Squamous Cell Carcinoma: A Systematic Review

There is no doubt that, along with surgery, chemoradiotherapy is an important treatment for esophageal squamous cell carcinoma (ESCC). Patients who respond well to chemoradiotherapy obtain great benefits toward overcoming their cancer, and so a more favorable prognosis. On the other hand, patients who do not respond well have wasted valuable time and experienced severe toxicity and seriously diminished quality of life, only to have their cancer recur with an unfavorable prognosis. For this reason, a reliable biomarker of chemoradiosensitivity in ESCC has long been sought. In this review, we will enumerate recently reported candidate biomarkers of chemoradiosensitivity in ESCC that have the potential for future clinical application.