Role of TNFα and leptin signaling in colon cancer incidence and tumor growth under obese phenotype

RBP7 functions as a tumor suppressor in HR + breast cancer by inhibiting the AKT/SREBP1 pathway and reducing fatty acid

BACKGROUND

Increasing evidence proves that RBP7 plays a significant role in breast cancer (BC). The present study was aimed to investigate the mechanism of RBP7.

METHODS

Western Blotting and qRT-PCR were performed for evaluating the expression levels. CCK8, colony forming, xenograft mouse model, wound healing and transwell assays were conducted to examine cell ability of proliferation, invasion and migration. Nile red staining and Oil red O staining were used for testing the lipid.

RESULTS

RBP7 was related to overall survival (OS) in patients with HR + BC. RBP7 protein was significantly decreased in HR + BC tissues and cells. RBP7 suppressed HR + BC cell proliferation in vitro and in vivo, and inhibited migration and invasion. RBP7 reduced fatty acid in HR + BC cells by inhibiting the AKT/SREBP1 pathway.

CONCLUSIONS

RBP7 may function as a tumor suppressor in HR + BC by inhibiting the AKT/SREBP1 pathway and reducing fatty acid.

LncRNA RASAL2-AS1 promotes METTL14-mediated m6A methylation in the proliferation and progression of head and neck squamous cell carcinoma

BACKGROUND

Long non-coding RNAs (lncRNAs) are key regulators of the 6-methyladenosine (m6A) epigenetic modification, playing a role in the initiation and progression of tumors. However, the regulatory mechanisms in head and neck squamous cell carcinoma (HNSCC) remain elusive. In this study, we investigated the molecular regulatory mechanisms of the lncRNA RASAL2-AS1 in the occurrence and development of HNSCC tumors.

METHODS

A bioinformatics analysis was conducted to analyze the expression level of RASAL2-AS1 in HNSCC and normal tissues. RASAL2-AS1 mRNA and protein levels were detected using RT-PCR and Western blotting. Wound healing, transwell assays, flow cytometry, M6A dot blot, and RNA immunoprecipitation experiments were conducted to explore the regulatory role of the RASAL2-AS1 and downstream targets METTL14/LIS1 signaling pathway in HNSCC. Immunohistochemical examination was conducted to evaluate the expression of METTL14 and LIS1 in HNSCC and normal tissues. A tumor xenograft model of BALB/c nude mice was established to assess the impact of RASAL2-AS1 on cell proliferation and growth.

RESULTS

RASAL2-AS1 high expression in HNSCC and cells deteriorated with survival rates of HNSCC. RASAL2-AS1 overexpression in HNSCC accelerated cell migration, colony formation, cell proliferation, cell cycle in S stage, while RASAL2-AS1 knockdown in HNSC cells inhibited cell cycle in G1 stage. After silencing METTL14, the above effects induced by overexpression of the RASAL2-AS1 were reversed. RASAL2-AS1 overexpression prompted LIS1 expression, whereas RASAL2-AS1 silencing reduced LIS1 levels in HNSCC cells, which was confirmed by immunohistological staining. Results demonstrated elevated expression of METTL14 or LIS1 in tongue cancer tissues. Overexpression of RASAL2-AS1 promoted tumor weight and tumor volume, which was counteracted by pcDNA3.1 RASAL2-AS1 plus silencing METTL14 and METTL14 and LIS1 were significantly decreased.

CONCLUSION

Our study highlights the functional importance of the LncRNA RASAL2-AS1 in HNSCC and might assist in the development of a prognostic stratification and therapeutic approach. Which regulates HNSCC with the dependence of m6a manner.

An Overview of Recent Findings that Shed Light on the Connection between Fat and Cancer

Obesity and cancer have been found to have a direct link in epidemiological studies. Obesity raises the risk of cancer and associated chronic disorders. Furthermore, an imbalance of adipokines, like leptins, plays a crucial role in neoplasm pathogenesis, cell migration, and thereby, cancer metastasis. Also, leptin increases human epidermal growth factor receptor 2 (HER2) protein levels through the STAT3-mediated (signal transducer and activator of transcription) upregulation of heat shock protein (Hsp90) in breast cancer cells. It has been noticed that insulin and insulin-like growth factors (IGFs) act as mitosis activators in the host and cancerous breast epithelial cells. The condition of hyperinsulinemia explains the positive association between colorectal cancer and obesity. Furthermore, in prostate cancer, an alteration in sex hormone levels, testosterone and dihydrotestosterone, has been reported to occur, along with increased oxidative stress, which is the actual cause of the tumors. Whereas, there have been two interconnected factors that play a crucial role in the psychological cycle concerned with lung cancer. The review article focuses on all the prospects of etiological mechanisms that have found linkage with obesity and breast, colon, lung, and prostate cancers. Furthermore, the article has also highlighted how these new insights into the processes occur and, due to which reasons, obesity contributes to tumorigenesis. This review provides a detailed discussion on the progression, which can assist in the development of new and innovative techniques to interfere in this process, and it has been supported with insights based on evidence literature on approved clinical treatments for obesity and cancer.

Cholesterol reprograms glucose and lipid metabolism to promote proliferation in colon cancer cells

Hypercholesterolemia is often correlated with obesity which is considered a risk factor for various cancers. With the growing population of hypercholesterolemic individuals, there is a need to understand the role of increased circulatory cholesterol or dietary cholesterol intake towards cancer etiology and pathology. Recently, abnormality in the blood cholesterol level of colon cancer patients has been reported. In the present study, we demonstrate that alteration in cholesterol levels (through a high-cholesterol or high-fat diet) increases the incidence of chemical carcinogen-induced colon polyp occurrence and tumor progression in mice. At the cellular level, low-density lipoprotein cholesterol (LDLc) and high-density lipoprotein cholesterol (HDLc) promote colon cancer cell proliferation by tuning the cellular glucose and lipid metabolism. Mechanistically, supplementation of LDLc or HDLc promotes cellular glucose uptake, and utilization, thereby, causing an increase in lactate production by colon cancer cells. Moreover, LDLc or HDLc upregulates aerobic glycolysis, causing an increase in total ATP production through glycolysis, and a decrease in ATP generation by OXPHOS. Interestingly, the shift in the metabolic status towards a more glycolytic phenotype upon the availability of cholesterol supports rapid cell proliferation. Additionally, an alteration in the expression of the molecules involved in cholesterol uptake along with the increase in lipid and cholesterol accumulation was observed in cells supplemented with LDLc or HDLc. These results indicate that colon cancer cells directly utilize the cholesterol associated with LDLc or HDLc. Moreover, targeting glucose metabolism through LDH inhibitor (oxamate) drastically abrogates the cellular proliferation induced by LDLc or HDLc. Collectively, we illustrate the vital role of cholesterol in regulating the cellular glucose and lipid metabolism of cancer cells and its direct effect on the colon tumorigenesis.

Effect of silkworm pupae (Bombyx mori) protein on colon cancer in nude mice: inhibition of tumor growth, oxidative stress and inflammatory response

Silkworm pupa (bombyx mori) protein (SPP) is a potential therapeutic bioactive substance that has anti-tumor activity against breast, liver, and gastric cancers. The aim of this study was to investigate the antitumor effect of SPP on colon cancer nude mice. Using a subcutaneous tumor formation method, we validated the therapeutic effect of SPP on colon cancer nude mice in vivo. Results showed that SPP was cytotoxic to tumor cells. SPP could protect the liver of the nude mice by lowering hepatic oxidative stress and regulating serum inflammation levels by decreasing TNF-α and IL-2 levels while in-creasing INF-γ levels. In addition, diminished Ki-67 protein, enhanced cleaved caspase-3 protein, di-minished Vimentin, enhanced E-cadherin. These findings suggested that SPP's antitumor activity may be achieved by reducing inflammation, inhibiting tumor proliferation and metastasis, and inducing apoptosis in cancer cells. In the future, SPP could be used as an anticancer drug, potentially providing a new source of drugs for the treatment of colon cancer.

Effects of Nutritious Meal Combined with Online Publicity and Education on Postoperative Nutrition and Psychological State in Patients with Low Rectal Cancer After Colostomy

Objective

To investigate the effects of nutritious meal combined with online publicity and education on postoperative nutrition and psychological state in patients with low rectal cancer after colostomy.

Methods

The clinic data of 88 patients with low rectal cancer who received the colostomy in our hospital (August 2020-August 2021) were retrospectively reviewed. Among them, 44 patients received nutritious meal combined with online publicity and education and they made up the study group, and the others were given conventional care and they made up the reference group. The nutrition indicators, scores of the World Health Organization Quality of Life (WHOQOL)-BREF, and other materials of the patients in the two groups were compared.

Results

After intervention, the various nutrition indicators, immune indexes, and WHOQOL-BREF score of the study group were all prominently higher than those of the reference group (P < 0.001). Compared with the reference group, the study group after intervention achieved markedly lower self-rating anxiety scale (SAS) score and self-rating depression scale (SDS) score (P < 0.001) and obviously lower total incidence of complications (P < 0.05).

Conclusion

Combining nutritious meal with online publicity and education can effectively improve the postoperative nutrition and immune function of the patients with low rectal cancer after colostomy, and this intervention contributes to releasing the patients' adverse emotions. Further study helps to provide these patients with favorable solutions.

Predictive Value of Preoperative Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratio in Determining the Stage of Colon Tumors

Introduction

Biomarkers such as the neutrophil-lymphocyte ratio (NLR) and the platelet-lymphocyte ratio (PLR) are associated with the colon tumor stage and prognosis. Therefore, in our study, we investigated whether these biomarkers are important in determining the colon cancer stage.

Materials and methods

The outcomes in 268 patients operated on with the diagnosis of colon cancer between January 2011 and March 2019 were retrospectively analyzed. The relationship of the stage of the patients with the NLR or PLR was evaluated. In addition, according to the stage of colorectal tumors, stage I and other stages (stages II, III, and IV) were compared in terms of NLR and PLR. Groups that had lymph node (LN) metastasis were compared with those that did not. Finally, groups with and without metastasis were also compared.

Results

In our cohort, 144 patients (57.6%) were male, and 84 (42.4%) were female. The mean age was found to be 68.28 ±12.71 years. The patients were evaluated according to their stages: 26 patients were stage I, 78 patients were stage II, 75 patients were stage III, and 19 patients were stage IV. There was a significant difference in NLR values between the groups (p: 0.05). Also, 104 patients were LN-negative (stages I-II), and 94 patients were LN-positive (stages III-IV). When PLR was compared between the two groups, no significant difference was found between tumor stages and these values (p: 0.099). However, there was a significant difference in NLR values (p: 0.034).

Conclusion 

Based on our findings, it has been concluded that increased PLR may not be associated with the colon cancer stage. However, the increase in NLR was found to be correlated with tumor stage and LN metastasis.

Serum and Tissue Expression Levels of Leptin and Leptin Receptor Are Putative Markers of Specific Feline Mammary Carcinoma Subtypes

Obesity is an established risk factor for breast cancer in post-menopausal women, being associated with elevated serum levels of leptin. Although overweight is a common condition in cat, the role of leptin and its receptor in feline mammary carcinoma remains unsettled. In this study, serum leptin and leptin receptor (ObR) levels were investigated in 58 cats with mammary carcinoma and compared with those of healthy animals, as were the expression levels of leptin and ObR in tumor tissues. The results showed that the Free Leptin Index is significantly decreased in cats with mammary carcinoma (p = 0.0006), particularly in those with luminal B and HER2-positive tumors, and that these animals also present significantly lower serum leptin levels (p < 0.0001 and p < 0.005, respectively). Interestingly, ulcerating tumors (p = 0.0005) and shorter disease-free survival (p = 0.0217) were associated to serum leptin levels above 4.17 pg/mL. In contrast, elevated serum ObR levels were found in all cats with mammary carcinoma (p < 0.0001), with levels above 16.89 ng/mL being associated with smaller tumors (p = 0.0118), estrogen receptor negative status (p = 0.0291) and increased serum levels of CTLA-4 (p = 0.0056), TNF-α (p = 0.0025), PD-1 (p = 0.0023), and PD-L1 (p = 0.0002). In tumor samples, leptin is overexpressed in luminal B and triple-negative carcinomas (p = 0.0046), whereas ObR is found to be overexpressed in luminal B tumors (p = 0.0425). Altogether, our results support the hypothesis that serum levels of leptin and ObR can be used as biomarkers of specific feline mammary carcinoma subtypes, and suggests the use of leptin antagonists as a therapeutic tool, reinforcing the utility of the cat as a cancer model.

Current mechanisms in obesity and tumor progression

PURPOSE OF REVIEW

Hyperadiposity, as present in obesity, is a substantial threat to cancer risk and prognosis. Studies that have investigated the link between obesity and tumor progression have proposed several mechanistic frameworks, yet, these mechanisms are not fully defined. Further, a comprehensive understanding of how these various mechanisms may interact to create a dynamic disease state is lacking in the current literature.

RECENT FINDINGS

Recent work has begun to explore not only discrete mechanisms by which obesity may promote tumor growth (for instance, metabolic and growth factor functions of insulin; inflammatory cytokines; adipokines; and others), but also how these putative tumor-promoting factors may interact.

SUMMARY

This review will highlight the present understanding of obesity, as it relates to tumor development and progression. First, we will introduce the impact of obesity in cancer within the dynamic tumor microenvironment, which will serve as a theme to frame this review. The core of this review will discuss recently proposed mechanisms that implicate obesity in tumor progression, including chronic inflammation and the role of pro-inflammatory cytokines, adipokines, hormones, and genetic approaches. Furthermore, we intend to offer current insight in targeting adipose tissue during the development of cancer prevention and treatment strategies.