Imaging colon cancer development in mice: IL-6 deficiency prevents adenoma in azoxymethane-treated Smad3 knockouts

Label-Free Optical Technologies to Enhance Noninvasive Endoscopic Imaging of Early-Stage Cancers

White light endoscopic imaging allows for the examination of internal human organs and is essential in the detection and treatment of early-stage cancers. To facilitate diagnosis of precancerous changes and early-stage cancers, label-free optical technologies that provide enhanced malignancy-specific contrast and depth information have been extensively researched. The rapid development of technology in the past two decades has enabled integration of these optical technologies into clinical endoscopy. In recent years, the significant advantages of using these adjunct optical devices have been shown, suggesting readiness for clinical translation. In this review, we provide an overview of the working principles and miniaturization considerations and summarize the clinical and preclinical demonstrations of several such techniques for early-stage cancer detection. We also offer an outlook for the integration of multiple technologies and the use of computer-aided diagnosis in clinical endoscopy.

Research progress on the application of optical coherence tomography in the field of oncology

Optical coherence tomography (OCT) is a non-invasive imaging technique which has become the “gold standard” for diagnosis in the field of ophthalmology. However, in contrast to the eye, nontransparent tissues exhibit a high degree of optical scattering and absorption, resulting in a limited OCT imaging depth. And the progress made in the past decade in OCT technology have made it possible to image nontransparent tissues with high spatial resolution at large (up to 2mm) imaging depth. On the one hand, OCT can be used in a rapid, noninvasive way to detect diseased tissues, organs, blood vessels or glands. On the other hand, it can also identify the optical characteristics of suspicious parts in the early stage of the disease, which is of great significance for the early diagnosis of tumor diseases. Furthermore, OCT imaging has been explored for imaging tumor cells and their dynamics, and for the monitoring of tumor responses to treatments. This review summarizes the recent advances in the OCT area, which application in oncological diagnosis and treatment in different types: (1) superficial tumors:OCT could detect microscopic information on the skin’s surface at high resolution and has been demonstrated to help diagnose common skin cancers; (2) gastrointestinal tumors: OCT can be integrated into small probes and catheters to image the structure of the stomach wall, enabling the diagnosis and differentiation of gastrointestinal tumors and inflammation; (3) deep tumors: with the rapid development of OCT imaging technology, it has shown great potential in the diagnosis of deep tumors such in brain tumors, breast cancer, bladder cancer, and lung cancer.

SESN1, negatively regulated by miR-377-3p, suppresses invasive growth of head and neck squamous cell carcinoma by interaction with SMAD3

Sestrin 1 (SESN1) is a stress-inducible protein that suppresses tumors in numerous cancers. However, the function of SESN1 in head and neck squamous cell carcinoma (HNSCC) is not clear and needs to be elucidated. Here, SESN1 expression was downregulated in HNSCC tissues and cell lines, and low SESN1 expression was positively correlated with poor prognosis in patients with HNSCC. Moreover, SESN1 overexpression inhibited the proliferation, migration, and invasion of HSC-6 and CAL-33 cells. In addition, the binding relationship between miR-377-3p and SESN1 was confirmed using luciferase reporter and RNA immunoprecipitation assays. Downregulation of SESN1 expression was consistent with high levels of miR-377-3p in HNSCC tissues. Linear regression analysis of clinical HNSCC tissues revealed a negative correlation between miR-377-3p and SESN1 expression. Moreover, co-immunoprecipitation mass spectrometry analysis revealed that SESN1 interacted with SMAD3, and SMAD3 reversed the increased proliferation, migration, and invasion of HSC-6 and CAL-33 cells caused by SESN1 knockdown. In conclusion, these findings provide evidence that SESN1 functions as a tumor suppressor and reveal the miR-377-3p-SESN1-SMAD3 regulatory axis that contributes to proliferation, migration, and invasion in HNSCC development, which may represent an interventional target for HNSCC therapy.

The JMJD Family Histone Demethylases in Crosstalk Between Inflammation and Cancer

Inflammation has emerged as a key player in regulating cancer initiation, progression, and therapeutics, acting as a double edged sword either facilitating cancer progression and therapeutic resistance or inducing anti-tumor immune responses. Accumulating evidence has linked the epigenetic modifications of histones to inflammation and cancer, and histone modifications-based strategies have shown promising therapeutic potentials against cancer. The jumonji C domain-containing (JMJD) family histone demethylases have exhibited multiple regulator functions in inflammatory processes and cancer development, and a number of therapeutic strategies targeting JMJD histone demethylases to modulate inflammatory cells and their products have been successfully evaluated in clinical or preclinical tumor models. This review summarizes current understanding of the functional roles and mechanisms of JMJD histone demethylases in crosstalk between inflammation and cancer, and highlights recent clinical and preclinical progress on harnessing the JMJD histone demethylases to regulate cancer-related inflammation for future cancer therapeutics.

Tumor models to assess immune response and tumor-microbiome interactions in colorectal cancer

Despite significant advances over the past 2 decades in preventive screening and therapy aimed at improving patient survival, colorectal cancer (CRC) remains the second most common cause of cancer death in the United States. The average 5-year survival rate of CRC patients with positive regional lymph nodes is only 40%, while less than 5% of patients with distant metastases survive beyond 5 years. There is a critical need to develop novel therapies that can improve overall survival in patients with poor prognoses, particularly since 60% of them are diagnosed at an advanced stage. Pertinently, immune checkpoint blockade therapy has dramatically changed how we treat CRC patients with microsatellite-instable high tumors. Furthermore, accumulating evidence shows that changes in gut microbiota are associated with the regulation of host antitumor immune response and cancer progression. Appropriate animal models are essential to deciphering the complex mechanisms of host antitumor immune response and tumor-gut microbiome metabolic interactions. Here, we discuss various mouse models of colorectal cancer that are developed to address key questions on tumor immune response and tumor-microbiota interactions. These CRC models will also serve as resourceful tools for effective preclinical studies.

The role of diosgenin in crohn’s disease

Inflammatory bowel disease (IBD) is a chronic idiopathic inflammation that can grossly affect the entire gastrointestinal tract (GIT) from the mouth to the anus. Crohn’s disease is the most known type of IBD and has been the focus of attention due to its increase in prevalence worldwide. Although the etiology is yet to be elucidated, recent studies have pointed out Crohn’s disease to arise from a complex interaction between environmental influences, genetic predisposition, and altered gut microbiota, resulting in dysregulated adaptive and innate responses. The presenting hallmarks of Crohn’s disease may include weight loss, nausea, vomiting, abdominal pain, diarrhea, fever, or chills. Treatment is usually done with many approved immunosuppressive drugs and surgery. However, a promising avenue from natural compounds is a safer therapy due to its safe natural active ingredients and the strong activity it shows in the treatment and management of diseases. Diosgenin, “a major biologically active natural steroidal sapogenin found in Chinese yam,” has been widely reported as a therapeutic agent in the treatment of various classes of disorders such as hyperlipidemia, inflammation, diabetes, cancer, infection, and immunoregulation. In this review, an analysis of literature data on diosgenin employed as a therapeutic agent for the treatment of Crohn’s disease is approached, to strengthen the scientific database and curtail the dreadful impact of Crohn’s disease.

Dysregulation of IL6/IL6R-STAT3-SOCS3 signaling pathway in IBD-associated colorectal dysplastic lesions as compared to sporadic colorectal adenomas in non-IBD patients

BACKGROUND

IL6-IL6R-STAT3-SOCS3 signaling pathway is known to play important roles in regulating intestinal epithelial homeostasis, in pathogenesis of inflammatory bowel disease (IBD), and in tumorigenesis of colorectal neoplasia. We studied the expressions of these factors in IBD-associated dysplasia and compared to sporadic colorectal adenomas in non-IBD individuals.

MATERIALS AND METHODS

The expression of IL6, IL6R, STAT3, and SOCS3 within dysplastic as well as background non-dysplastic epithelial cells was evaluated by immunohistochemistry in 26 sporadic colorectal adenomas in non-IBD patients, 32 adenoma-like and 30 non-adenoma-like dysplastic lesions in IBD (41 ulcerative colitis, 21 Crohn's disease) patients. The level of expression of each factor was arbitrarily scored as 0, 1, 2, and 3.

RESULTS

In both IBD and non-IBD lesions, neoplastic epithelium showed a higher expression of all factors, except the IL6R, as compared to non-neoplastic epithelium. For non-neoplastic epithelium between IBD and non-IBD settings, the colitic epithelium showed a similar IL6, lower IL6R, higher STAT3, and higher SOCS3 expression. As compared to non-IBD adenomas, IBD-associated dysplasia showed a significantly lower IL6, lower IL6R, higher STAT3, and lower SOCS3 expression. Most notably, a parallel-elevation pattern of STAT3/SOCS3 expressions was seen in non-IBD adenomas but an inverse-expression pattern of STAT3/SOCS3 seen in IBD dysplastic lesions. No significant differences existed between adenoma-like and non-adenoma-like lesions.

CONCLUSIONS

IL6/IL6R-STAT3-SOCS3 signaling pathway does not seem to be preferentially associated with IBD-associated dysplasia. However, the STAT3-SOCS3 interaction appears dysregulated in IBD, characterized by a loss of STAT3/SOCS3 balance,i.e., loss of the normal negative regulation of SOCS3.

Consumption of Low-Dose of Ethanol Suppresses Colon Tumorigenesis in 1,2-Dimethylhydrazine-Treated Rats

The effect of low-dose of ethanol consumption on the development of colon cancer is unclear. This study aimed to investigate the effects of low-dose ethanol (0.5%, 1%, and 2% [v/v] ethanol in drinking water) for 28 wk on colon tumor incidence in rats injected with 1,2-dimethylhydrazine. Body weight, fluid and food consumption, and the total numbers of colon adenomas (mild-, moderate-, and severe-grade dysplasia) per rat were unaffected by ethanol consumption. However, the numbers of severe-grade dysplasia were significantly reduced by 1% ethanol compared with the control (0% ethanol; -93%) but not by 0.5% and 2% ethanol. Although the numbers of total adenocarcinomas were unaffected, those of total of adenomas and adenocarcinomas together were significantly reduced by 0.5% and 1% ethanol (-39% and -41%, respectively). Intriguingly, real-time PCR assay indicated the abundance of cecal Clostridium leptum (a putative immunosuppressor) was the least in rats received 1% ethanol. Furthermore, 1% ethanol markedly increased colonic mRNA of IL-6, a putative suppressor of regulatory T-cells and cytoprotector. This study provides the first evidence for the potential of 1% ethanol, but not 2% ethanol, to prevent colon tumorigenesis in rats, supporting the J-curve hypothesis of the effect of low-dose alcohol on health. Further, the modulation of C. leptum and expression of IL-6, potentially linking to carcinogenesis, by 1% ethanol may provide an insight into the underlying mechanisms of the anti-colon tumor effect.

Intermittent Dosing with Sulindac Provides Effective Colorectal Cancer Chemoprevention in the Azoxymethane-Treated Mouse Model

Sulindac is an NSAID that can provide effective chemoprevention for colorectal cancer. In this study, alternative dosing regimens of sulindac were evaluated for their chemoprevention effectiveness in the azoxymethane-treated A/J mouse model of colorectal cancer. High-resolution endoscopic optical coherence tomography was utilized to time-serially measure tumor number and tumor burden in the distal colon as the biological endpoints. Four treatment groups were studied: (i) daily for 20 weeks (sulindac-daily); (ii) for 2 weeks, then no sulindac for 2 weeks, cycle repeated 5 times (sulindac-2); (iii) for 10 weeks ("on"), then no sulindac for 10 weeks ("off"; sulindac-10); and (iv) no sulindac (sulindac-none). Sulindac-2 and sulindac-daily had statistically significantly lower final tumor counts and slopes (change in number of tumors per week) when compared with sulindac-none (P < 0.0001). All of the treatment groups had statistically significantly lower final tumor burdens and slopes when compared with sulindac-none (P < 0.001). There was a prolonged latency period in the sulindac-10 group, with no significant difference between the "off" portion of this treatment and sulindac-none. These results suggest that, although daily doses of sulindac provide the most optimal effects, intermittent doses of sulindac in a 50% duty cycle with an overall 4-week period (sulindac-2 model) can provide highly effective chemoprevention of colorectal cancer in this model. After cessation of sulindac treatment (sulindac-10 "off"), there is no evidence of either a persistent chemopreventive effect or a rebound effect. Cancer Prev Res; 10(8); 459-66. ©2017 AACR.