Effect of Estradiol in an Azoxymethane/Dextran Sulfate Sodium-Treated Mouse Model of Colorectal Cancer: Implication for Sex Difference in Colorectal Cancer Development

Differences in the role of Gper1 in colorectal cancer progression depending on sex

To evaluate the role of 17β-oestradiol (E2) in the sex-dependent progression of colorectal cancer (CRC), the present study focused on E2 signalling mediated via the nuclear receptors [oestrogen receptor (ESR)1 and ESR2] and the membrane G protein-coupled oestrogen receptor 1 (Gper1) in males and females diagnosed with CRC. This study also investigated Gper1 signalling in the CRC cell lines DLD1 and LoVo, which differ in the p53 pathway. In cancer tissue, Gper1 becomes by far the most abundant E2 receptor due to an increase in Gper1 and a decrease in ESR2 expression. These changes are more prominent in males than in females. More pronounced differences in Gper1 expression between cancer and adjacent tissues were observed in males in lower stages compared with those in higher stages of disease and females. High expression of Gper1 was associated with worse survival in males without nodal involvement but not in females. The expression of E2 receptors in the CRC cell lines DLD1 and LoVo resembles that of human cancer tissue. Silencing of Gper1 (siGper1) caused an increase in the rate of metabolism in LoVo cells with wild-type tp53. In DLD1 cells with the mutated form of tp53, siGper1 did not exert this effect. High levels of Gper1 were associated with worse survival and could contribute to sex-dependent changes in the CRC prognosis. Tumour suppressor effects of Gper1 were, at least to some extent, dependent on signalling downstream of p53, which was more frequently deficient in males than in females. Overall, this suggests that up-regulation of Gper1 (or administration of a Gper1 agonist) would be more beneficial for patients with wild-type tp53.

Standardization of a Preclinical Colon Cancer Model in Male and Female BALB/c Mice: Macroscopic and Microscopic Characterization from Pre-Neoplastic to Tumoral Lesions

Background/Objetives: This study standardized a chemically induced colorectal cancer (CRC) model using azoxymethane (AOM) and dextran sodium sulfate (DSS) in BALB/c mice, replicating the progression from preneoplastic lesions to adenocarcinoma observed in human colorectal carcinogenesis. Methods: The CCR-AOM/DSS model was standardized in male and female BALB/c mice. Two protocols were tested. Subsequently, the positive control group was established with nine evaluation points. Tumor progression was characterized histopathologically and corroborated by methylene blue staining and scanning electron microscopy. Results: Two cycles of 2% DSS combined with a single injection of AOM (10 mg/kg) were necessary to induce adenocarcinoma in 100% of the mice, with no significant sex-based differences in tumor development. Females showed earlier tumor susceptibility under certain protocols. Inflammatory processes played a critical role in tumorigenesis, with neutrophil infiltration and fibrosis observed. Conclusions: The findings align with previous reports, emphasizing the influence of DSS cycles, molecular weight, and mouse strain on model outcomes. This standardized model provides a reliable platform for the preclinical evaluation of novel preventive and therapeutic strategies for CRC.

Ninjurin1 deficiency differentially mitigates colorectal cancer induced by azoxymethane and dextran sulfate sodium in male and female mice

This study investigated the role of Ninjurin1 (Ninj1), encoding a small transmembrane protein, in colitis-associated colon tumorigenesis in relation to sex hormones. Male and female wild-type (WT) and Ninj1 knockout (KO) mice were treated with azoxymethane (AOM) and dextran sulfate sodium (DSS), with or without testosterone propionate (TP). At week 2 (acute colitis stage), Ninj1 KO exhibited an alleviation in the colitis symptoms in both male and female mice. The M2 macrophage population increased and CD8+ T cell population decreased only in the female Ninj1 KO than in the female WT AOM/DSS group. In the female AOM/DSS group, TP treatment exacerbated colon shortening in the Ninj1 KO than in the WT. At week 13 (tumorigenesis stage), male Ninj1 KO mice had fewer tumors, but females showed similar tumors. In the WT AOM/DSS group, females had more M2 macrophages and fewer M1 macrophages than males, but this difference was absent in Ninj1 KO mice. In the Ninj1 KO versus WT group, the expression of pro-inflammatory mediators and Ho-1 and CD8+ T cell populations decreased in both female and male Ninj1 KO mice. In the WT group, M2 macrophage populations were increased by AOM/DSS treatment and decreased by TP treatment. However, neither treatment changed the cell populations in the Ninj1 KO group. These results suggest that Ninj1 is involved in colorectal cancer development in a testosterone-dependent manner, which was different in male and female. This highlights the importance of considering sex disparities in understanding Ninj1's role in cancer pathogenesis.

Estrogen-related differences in antitumor immunity and gut microbiome contribute to sexual dimorphism of colorectal cancer

Colorectal cancer (CRC) is a multifaceted disease whose development and progression varies depending on tumor location, age of patients, infiltration of immune cells within cancer lesions, and the tumor microenvironment. These pathophysiological characteristics are additionally influenced by sex-related differences. The gut microbiome plays a role in initiation and progression of CRC, and shapes anti-tumor immune responses but how responsiveness of the immune system to the intestinal microbiota may contribute to sexual dimorphism of CRC is largely unknown. We studied survival, tumor-infiltrating immune cell populations and tumor-associated microbiome of a cohort of n = 184 male and female CRC patients through high-dimensional single-cell flow cytometry and 16S rRNA gene sequencing. We functionally tested the immune system-microbiome interactions in in-vivo and in-vitro models of the disease. High-dimensional single-cell flow cytometry showed that female patients are enriched by tumor-infiltrating invariant Natural Killer T (iNKT) cells but depleted by cytotoxic T lymphocytes. The enrichment of oral pathobionts and a reduction of β-glucuronidase activity are distinctive traits characterizing the gut microbiome of female patients affected by CRC. Functional assays using a collection of human primary iNKT cell lines demonstrated that the gut microbiota of female patients functionally impairs iNKT cell anti-tumor functions interfering with the granzyme-perforin cytotoxic pathway. Our results highlight a sex-dependent functional relationship between the gut microbiome, estrogen metabolism, and the decline of cytotoxic T cell responses, contributing to the sexual dimorphism observed in CRC patients with relevant implications for precision medicine and the design of targeted therapeutic approaches addressing sex bias in cancer.

Direct and indirect effects of estrogens, androgens and intestinal microbiota on colorectal cancer

Sex differences in colorectal cancer (CRC) has received considerable research attention recently, particularly regarding the influence of sex hormones and the intestinal microbiota. Estrogen, at the genetic and epigenetic levels, directly inhibits CRC cell proliferation by enhancing DNA mismatch repair, regulating miRNAs, blocking the cell cycle, and modulating ion channels. However, estradiol's activation of GPER promotes oncogene expression. Conversely, androgen contributes to epigenetic dysregulation and CRC progression via nuclear receptors while inducing apoptosis through membrane receptors. Specific gut microorganisms produce genotoxins and oncogenic metabolites that damage colonic cell DNA and contribute to cancer induction. Regarding the tumor microenvironment, estrogen mitigates intestinal inflammation, reverses immunosuppression, increases gut microbiome diversity and commensal bacteria abundance, and decreases pathogen enrichment. On the contrary, androgen disrupts intestinal microecology, diminish immunotherapy efficacy, and exacerbate colonic inflammation and tumor growth. The impact of estrogen and androgen is closely tied to their receptor status, elucidating their dual roles in CRC pathogenesis. This review comprehensively discusses the direct and indirect effects of sex hormones and the intestinal microbiota on CRC, considering environmental factors such as diet and lifestyle to propose novel prevention and treatment strategies.

Intricate roles of estrogen and estrogen receptors in digestive system cancers: a systematic review

Gender disparities are evident across different types of digestive system cancers, which are typically characterized by a lower incidence and mortality rate in females compared to males. This finding suggests a potential protective role of female steroid hormones, particularly estrogen, in the development of these cancers. Estrogen is a well-known sex hormone that not only regulates the reproductive system but also exerts diverse effects on non-reproductive organs mediated through interactions with estrogen receptors (ERs), including the classic (ERα and ERβ) and non-traditional ERs [G protein-coupled estrogen receptor (GPER)]. Recent advances have contributed to our comprehension of the mechanisms underlying ERs in digestive system cancers. In this comprehensive review we summarize the current understanding of the intricate roles played by estrogen and ERs in the major types of digestive system cancers, including hepatocellular, pancreatic, esophageal, gastric, and colorectal carcinoma. Furthermore, we discuss the potential molecular mechanisms underlying ERα, ERβ, and GPER effects, and propose perspectives on innovative therapies and preventive measures targeting the pathways regulated by estrogen and ERs. The roles of estrogen and ERs in digestive system cancers are complicated and depend on the cell type and tissue involved. Additionally, deciphering the intricate roles of estrogen, ERs, and the associated signaling pathways may guide the discovery of novel and tailored therapeutic and preventive strategies for digestive system cancers, eventually improving the care and clinical outcomes for the substantial number of individuals worldwide affected by these malignancies.

Tocotrienol suppresses colitis-associated cancer progression through TLR4 signaling in a mouse model of colorectal cancer

This study aimed to evaluate the preventive efficacy of tocotrienol in inhibiting the nuclear factor-kappa B (NF-κB) mediated inflammation pathways in colorectal cancer. We utilized the azoxymethane (AOM) and dextran sulfate sodium salt (DSS) to induce colitis-associated colorectal cancer (CAC) mice model. In generating a CAC model, mice were intraperitoneally injected with AOM at a concentration of 10 mg/kg body weight. Seven days after the AOM injection, mice drinking water containing 3 % DSS for 1 week, followed by a 2-week period of regular water. This cycle of DSS treatment (1-week 3 % DSS+2-week water) was repeated for two additional cycles. Mice were randomly divided into five groups (n = 20/group), including Blank group, Model group, three different dosages tocotrienol groups (Low dose group [50 mg/kg], Medium dose group [75 mg/kg], and High dose group [100 mg/kg]). The protective effects of tocotrienol were assessed using histological, flow cytometry, western blot and mouse Luminex assay. Compared with the blank group, expressions of toll-like receptor 4 (TLR4), myeloid differentiation protein 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF-6), NF-κB, Interleukin (IL)-6 and tumor necrosis factor (TNF) -α were increased in model group, while IL-4 and IL-10 were decreased in model group (P<0.05). Tocotrienol prevented carcinogenesis and decreased the IL-6, TNF-α, MyD88, TLR4, TRAF-6 and NF-κB expression levels, compared with the model group (P<0.05). Compared with the model group, the expression of IL-10 was increased in medium dose group and high dose group (P<0.05). The protective effects of tocotrienol may be related to the inhibition of TLR4 /MyD88 /NF-κB mediated inflammatory signaling pathways. Therefore, the use of tocotrienol can improve the abnormal expression of cytokines in a mouse model of colorectal cancer and inhibit the occurrence and development of colorectal cancer.

Sex difference in human diseases: mechanistic insights and clinical implications

Sex characteristics exhibit significant disparities in various human diseases, including prevalent cardiovascular diseases, cancers, metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Risk profiles and pathological manifestations of these diseases exhibit notable variations between sexes. The underlying reasons for these sex disparities encompass multifactorial elements, such as physiology, genetics, and environment. Recent studies have shown that human body systems demonstrate sex-specific gene expression during critical developmental stages and gene editing processes. These genes, differentially expressed based on different sex, may be regulated by androgen or estrogen-responsive elements, thereby influencing the incidence and presentation of cardiovascular, oncological, metabolic, immune, and neurological diseases across sexes. However, despite the existence of sex differences in patients with human diseases, treatment guidelines predominantly rely on male data due to the underrepresentation of women in clinical trials. At present, there exists a substantial knowledge gap concerning sex-specific mechanisms and clinical treatments for diverse diseases. Therefore, this review aims to elucidate the advances of sex differences on human diseases by examining epidemiological factors, pathogenesis, and innovative progress of clinical treatments in accordance with the distinctive risk characteristics of each disease and provide a new theoretical and practical basis for further optimizing individualized treatment and improving patient prognosis.

Sexual dimorphism of colorectal cancer in humans and colorectal tumors in a murine model

Introduction

In colorectal cancer, men exhibit a higher incidence than women, and there is a disturbance in the levels of sex steroids in serum in patients with this disease. Consistently, in animals, males have greater tumor growth than females in diverse models. Nevertheless, the role of sex steroids is not well established. For that, we analyzed the effect of the principal gonadal sex steroids in both sexes. We determined sex as a statistically risk factor for colorectal cancer with data obtained from GLOBOCAN database.

Methods

To induce colorectal tumors, we used the gold standard chemical method of azoxymethane and dextran sulphate of sodium. To evaluate the role of sex steroids, we gonadectomized independent males and female animals, reconstituting and substituting them with 17β estradiol and dihydrotestosterone. Finally, we determined, in vitro, the proliferation of a human cell line exposed to 17β estradiol, testosterone, or dihydrotestosterone. Sex, as a risk factor for colorectal cancer, showed a statistically significant susceptibility of men over 50 years old.

Results

In vivo, males develop a greater number of tumors and with a larger size than females. In males, orchiectomy prevents tumor growth, whereas in females, ovariectomy promotes the development of neoplasms. DHT acts as a protumoral agent in both sexes. 17β estradiol reduces tumor growth in females but enhances it in males, showing a dimorphic effect. In vitro studies reveal that estradiol decreases the proliferation of the HCT-116 colon cancer cell line, while testosterone boosts proliferation in these cells. Interestingly, dihydrotestosterone does not influence proliferation.

17β-estradiol in colorectal cancer: friend or foe?

Colorectal cancer (CRC) is a common gastrointestinal malignancy with higher incidence and mortality rates in men compared to women, potentially due to the effects of estrogen signaling. There is substantial evidence supporting the significant role of 17β-Estradiol (E2) in reducing CRC risk in females, although this perspective remains debated. E2 has been demonstrated to inhibit CRC cell proliferation and migration at the cellular level by enhancing DNA mismatch repair, modulating key gene expression, triggering cell cycle arrest, and reducing activity of migration factors. Furthermore, E2 contributes to promote a tumor microenvironment unfavorable for CRC growth by stimulating ERβ expression, reducing inflammatory responses, reversing immunosuppression, and altering the gut microbiome composition. Conversely, under conditions of high oxidative stress, hypoxia, and nutritional deficiencies, E2 may facilitate CRC development through GPER-mediated non-genomic signaling. E2's influence on CRC involves the genomic and non-genomic signals mediated by ERβ and GPER, respectively, leading to its dual roles in anticancer activity and carcinogenesis. This review aims to summarize the potential mechanisms by which E2 directly or indirectly impacts CRC development, providing insights into the phenomenon of sexual dimorphism in CRC and suggesting potential strategies for prevention and treatment.

Sexual dimorphism in colorectal cancer: molecular mechanisms and treatment strategies

INTRODUCTION

Sexual dimorphism significantly influences cancer incidence and prognosis. Notably, females exhibit a lower risk and favorable prognosis for non-reproductive cancers compared to males, a pattern observable beyond the scope of risk behaviors such as alcohol consumption and smoking. Colorectal cancer, ranking third in global prevalence and second in mortality, disproportionately affects men. Sex steroid hormones, particularly estrogens and androgens, play crucial roles in cancer progression, considering epidemiological in vivo and in vitro, in general estrogens imparting a protective effect in females and androgens correlating with an increasing risk of colorectal cancer development.

MAIN BODY

The hormonal impact on immune response is mediated by receptor interactions, resulting in heightened inflammation, modulation of NF-kB, and fostering an environment conducive to cancer progression and metastasis. These molecules also influence the enteric nervous system, that is a pivotal in neuromodulator release and intestinal neuron stimulation, also contributes to cancer development, as evidenced by nerve infiltration into tumors. Microbiota diversity further intersects with immune, hormonal, and neural mechanisms, influencing colorectal cancer dynamics. A comprehensive understanding of hormonal influences on colorectal cancer progression, coupled with the complex interplay between immune responses, microbiota diversity and neurotransmitter imbalances, underpins the development of more targeted and effective therapies.

CONCLUSIONS

Estrogens mitigate colorectal cancer risk by modulating anti-tumor immune responses, enhancing microbial diversity, and curbing the pro-tumor actions of the sympathetic and enteric nervous systems. Conversely, androgens escalate tumor growth by dampening anti-tumor immune activity, reducing microbial diversity, and facilitating the release of tumor-promoting factors by the nervous system. These findings hold significant potential for the strategic purposing of drugs to fine-tune the extensive impacts of sex hormones within the tumor microenvironment, promising advancements in colorectal cancer therapies.

Sex Difference of Colon Adenoma Pathway and Colorectal Carcinogenesis

Colorectal cancer (CRC) is one of the most common causes of cancer morbidity in both sexes but shows sex differences. First, sex-specific differences in tumor recurrence and survival rates have been reported. For example, the development of CRC is found about 1.5 times higher and 4-8 years earlier in males compared to females, suggesting the protective role of estrogen in the disease. Furthermore, female patients have a higher risk of developing right-sided (proximal) colon cancer than male patients, which is known to have more aggressive clinical character compared to left-sided (distal) colon cancer. That is, left and right CRCs show differences in carcinogenic mechanism, that the chromosomal instability pathway is more common in left colon cancer while the microsatellite instability and serrated pathways are more common in right colon cancer. It is thought that there are sex-based differences on the background of carcinogenesis of CRC. Sex differences of CRC have two aspects, sexual dimorphism (biological differences in hormones and genes) and gender differences (non-biological differences in societal attitudes and behavior). Recently, sex difference of colon adenoma pathway and sexual dimorphism in the biology of gene and protein expression, and in endocrine cellular signaling in the CRC carcinogenesis have been accumulated. In addition, behavioral patterns can lead to differences in exposure to risk factors such as drinking or smoking, diet and physical activity. Therefore, understanding sex/gender-related biological and sociocultural differences in CRC risk will help in providing strategies for screening, treatment and prevention protocols to reduce the mortality and improve the quality of life. In this review, sex/gender differences in colon adenoma pathway and various aspects such as clinicopathological, biological, molecular, and socio-cultural aspects of CRC were described.

Gα12 and endoplasmic reticulum stress-mediated pyroptosis in a single cycle of dextran sulfate-induced mouse colitis

Inflammatory bowel disease (IBD) pathogenesis involves complex inflammatory events and cell death. Although IBD involves mainly necrosis in the digestive tract, pyroptosis has also been recognized. Nonetheless, the underlying basis is elusive. Gα12/13 overexpression may affect endoplasmic reticulum (ER) stress. This study examined how Gα12/13 and ER stress affect pyroptosis using dextran sulfate sodium (DSS)-induced colitis models. Gα12/13 levels were increased in the distal and proximal colons of mice exposed to a single cycle of DSS, as accompanied by increases of IRE1α, ATF6, and p-PERK. Moreover, Il-6, Il-1β, Ym1, and Arg1 mRNA levels were increased with caspase-1 and IL-1β activation, supportive of pyroptosis. In the distal colon, RIPK1/3 levels were enhanced to a greater degree, confirming necroptosis. By contrast, the mice subjected to three cycles of DSS treatments showed decreases of Gα12/13, as accompanied by IRE1α and ATF6 suppression, but increases of RIPK1/3 and c-Cas3. AZ2 treatment, which inhibited Gα12, has an anti-pyroptotic effect against a single cycle of colitis. These results show that a single cycle of DSS-induced colitis may cause ER stress-induced pyroptosis as mediated by Gα12 overexpression in addition to necroptosis, but three cycles model induces only necroptosis, and that AZ2 may have an anti-pyroptotic effect.

Sex differences in colorectal cancer: with a focus on sex hormone-gut microbiome axis

Sexual dimorphism has been observed in the incidence and prognosis of colorectal cancer (CRC), with men generally exhibiting a slightly higher incidence than women. Research suggests that this difference may be attributed to variations in sex steroid hormone levels and the gut microbiome. The gut microbiome in CRC shows variations in composition and function between the sexes, leading to the concept of 'microgenderome' and 'sex hormone-gut microbiome axis.' Conventional research indicates that estrogens, by promoting a more favorable gut microbiota, may reduce the risk of CRC. Conversely, androgens may have a direct pro-tumorigenic effect by increasing the proportion of opportunistic pathogens. The gut microbiota may also influence sex hormone levels by expressing specific enzymes or directly affecting gonadal function. However, this area remains controversial. This review aims to explore the differences in sex hormone in CRC incidence, the phenomenon of sexual dimorphism within the gut microbiome, and the intricate interplay of the sex hormone-gut microbiome axis in CRC. The objective is to gain a better understanding of these interactions and their potential clinical implications, as well as to introduce innovative approaches to CRC treatment.

Role of gonadally synthesized steroid hormones in the colorectal cancer microenvironment

Objective

To understand the relationship between steroid hormones synthesized by the gonads and colorectal cancer as well as its tumor microenvironment, in the expectation of providing new ideas in order to detect and treat colorectal cancer.

Methods

Through reviewing the relevant literature at home and abroad, we summarized that androgens promote the growth of colorectal cancer, and estrogens and progesterone help prevent bowel cancer from developing; these three hormones also have a relevant role in the cellular and other non-cellular components of the tumor microenvironment of colorectal cancer.

Conclusion

The current literature suggests that androgens, estrogens, and progesterone are valuable in diagnosing and treating colorectal cancer, and that androgens promote the growth of colorectal cancer whereas estrogens and progesterone inhibit colorectal cancer, and that, in addition, the receptors associated with them are implicated in the modulation of a variety of cellular components of the microenvironment of colorectal cancer.

ATP ion channel P2X7 receptor as a regulatory molecule in the progression of colorectal cancer

Large amounts of adenosine triphosphate (ATP), a natural P2X7 receptor activator, are released during colorectal carcinogenesis. P2X7 receptor activation regulates the activity of colorectal cancer (CRC) cells by mediating intracellular signal transduction. Importantly, the opening and activation of membrane pores of P2X7 receptor are different, which can play a dual role in promoting or inhibiting the progression of CRC. These can also depend on P2X7 receptor to regulate the activities of immune cells in the microenvironment, play the functions of immune regulation, immune escape and immune monitoring. While the use of P2X7 receptor antagonists (such as BBG, A438079 and A740003) can play a certain inhibitory pharmacological role on the activity of CRC. Therefore, in this paper, the mechanism and immunomodulatory function of P2X7 receptor involved in the progression of CRC were discussed. Moreover, we discussed the effect of antagonizing the activity of P2X7 receptor on the progression of CRC. So P2X7 receptor may be a new pharmacological molecular target for the treatment of CRC.

Estrogen plays an important role by influencing the NLRP3 inflammasome

The nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is an important part of the natural immune system that plays an important role in many diseases. Estrogen is a sex hormone that plays an important role in controlling reproduction and regulates many physiological and pathological processes. Recent studies have indicated that estrogen is associated with disease progression. Estrogen can ameliorate some diseases (e. g, sepsis, mood disturbances, cerebral ischemia, some hepatopathy, Parkinson's disease, amyotrophic lateral sclerosis, inflammatory bowel disease, spinal cord injury, multiple sclerosis, myocardial ischemia/reperfusion injury, osteoarthritis, and renal fibrosis) by inhibiting the NLRP3 inflammasome. Estrogen can also promote the development of diseases (e.g., ovarian endometriosis, dry eye disease, and systemic lupus erythematosus) by upregulating the NLRP3 inflammasome. In addition, estrogen has a dual effect on the development of cancers and asthma. However, the mechanism of these effects is not summarized. This article reviewed the progress in understanding the effects of estrogen on the NLRP3 inflammasome and its mechanisms in recent years to provide a theoretical basis for an in-depth study.

NOD-like Receptor Signaling Pathway in Gastrointestinal Inflammatory Diseases and Cancers

Nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) are intracellular proteins with a central role in innate and adaptive immunity. As a member of pattern recognition receptors (PRRs), NLRs sense specific pathogen-associated molecular patterns, trigger numerous signaling pathways and lead to the secretion of various cytokines. In recent years, cumulative studies have revealed the significant impacts of NLRs in gastrointestinal (GI) inflammatory diseases and cancers. Deciphering the role and molecular mechanism of the NLR signaling pathways may provide new opportunities for the development of therapeutic strategies related to GI inflammatory diseases and GI cancers. This review presents the structures and signaling pathways of NLRs, summarizes the recent advances regarding NLR signaling in GI inflammatory diseases and GI cancers and describes comprehensive therapeutic strategies based on this signaling pathway.

The influence of COVID-19 on colorectal cancer was investigated using bioinformatics and systems biology techniques

Introduction

Coronavirus disease 2019 (COVID-19) is a global pandemic and highly contagious, posing a serious threat to human health. Colorectal cancer (CRC) is a risk factor for COVID-19 infection. Therefore, it is vital to investigate the intrinsic link between these two diseases.

Methods

In this work, bioinformatics and systems biology techniques were used to detect the mutual pathways, molecular biomarkers, and potential drugs between COVID-19 and CRC.

Results

A total of 161 common differentially expressed genes (DEGs) were identified based on the RNA sequencing datasets of the two diseases. Functional analysis was performed using ontology keywords, and pathway analysis was also performed. The common DEGs were further utilized to create a protein-protein interaction (PPI) network and to identify hub genes and key modules. The datasets revealed transcription factors-gene interactions, co-regulatory networks with DEGs-miRNAs of common DEGs, and predicted possible drugs as well. The ten predicted drugs include troglitazone, estradiol, progesterone, calcitriol, genistein, dexamethasone, lucanthone, resveratrol, retinoic acid, phorbol 12-myristate 13-acetate, some of which have been investigated as potential CRC and COVID-19 therapies.

Discussion

By clarifying the relationship between COVID-19 and CRC, we hope to provide novel clues and promising therapeutic drugs to treat these two illnesses.

Characteristic submucosal alteration in biliary carcinogenesis of pancreaticobiliary maljunction with a focus on inflammasome activation

BACKGROUND

This study investigated submucosal alterations in biliary carcinogenesis of pancreaticobiliary maljunction (PBM).

METHODS

Thirty-three patients with PBM (including seven with gallbladder [GB] cancer), four with neither biliary tract cancer nor PBM who underwent pancreaticoduodenectomy (controls), and seven with chronic cholecystitis without PBM were enrolled. Protein expression of α-smooth muscle actin (αSMA), CD68, and CD204 in the GB lamina propria and that of NLRP3 and caspase 1 in the GB epithelium and lamina propria were examined.

RESULTS

Compared with the control and cholecystitis groups, αSMA expression was higher in the cancerous part (stroma) of the GB in patients with GB cancer + PBM and in the lamina propria of patients with PBM. The CD204/CD68 ratio in the lamina propria was higher in the PBM group than in the control and cholecystitis groups. NLRP3 and caspase 1 expression in both the lamina propria and epithelium was higher in the PBM than control group. In the PBM group, NLRP3- and caspase 1-positive cells in the lamina propria were located near the epithelium.

CONCLUSION

Activated fibroblasts and M2 macrophages in the GB lamina propria may be associated with biliary carcinogenesis of PBM, possibly through inflammasome activation.

Influence of location-dependent sex difference on PD-L1, MMR/MSI, and EGFR in colorectal carcinogenesis

BACKGROUND

The incidence and mortality rates of colorectal cancer (CRC) has been reported to be strongly associated to sex/gender difference. CRC shows sexual dimorphism, and sex hormones have been shown to affect the tumor immune microenvironment. This study aimed to investigate location-dependent sex differences in tumorigenic molecular characteristics in patients with colorectal tumors, including adenoma and CRC.

METHODS

A total of 231 participants, including 138 patients with CRC, 55 patients with colorectal adenoma, and 38 healthy controls, were recruited between 2015 and 2021 at Seoul National University Bundang Hospital. All patients underwent colonoscopy and acquired tumor lesion samples were further analyzed for programmed death-ligand 1 (PD-L1), epidermal growth factor receptor (EGFR) expression, deficient mismatch repair (dMMR), and microsatellite instability (MSI) status. This study was registered with ClinicalTrial.gov, number NCT05638542.

RESULTS

The average of combined positive score (CPS) was higher in serrated lesions and polyps (lesions/polyps) compared to conventional adenomas (5.73 and 1.41, respectively, P < 0.001). No significant correlation was found between sex and PD-L1 expression within the groups, regardless of histopathological diagnosis. In multivariate analysis where each sex was further stratified by tumor location due to their interaction in CRC, PD-L1 expression was inversely correlated with males having proximal CRC with a CPS cutoff of 1 (Odds ratio (OR) 0.28, P = 0.034). Females with proximal CRC showed a significant association with dMMR/MSI-high (OR 14.93, P = 0.032) and high EGFR expression (OR 4.17, P = 0.017).

CONCLUSION

Sex and tumor location influenced molecular features such as PD-L1, MMR/MSI status and EGFR expression in CRC, suggesting a possible underlying mechanism of sex-specific colorectal carcinogenesis.

Changes in Gut Microbiome upon Orchiectomy and Testosterone Administration in AOM/DSS-Induced Colon Cancer Mouse Model

PURPOSE

Sex hormones are known to affect the gut microbiota. Previously, we reported that endogenous and exogenous testosterone are associated with colorectal cancer (CRC) development and submucosal invasion. In the present study, we investigated whether the gut microbiota is affected by orchiectomy (ORX) and testosterone propionate (TP) administration using an azoxymethane/dextran sulfate sodium (AOM/DSS)-induced CRC mouse model.

MATERIALS AND METHODS

Gut microbiota was evaluated by means of 16S rRNA gene sequencing of stool DNA extracted from feces that were obtained at 13 weeks after AOM injection (from 22-week-old animals) and stored in a gas-generating pouch.

RESULTS

The increase in microbial diversity (Chao1 and Phylogenetic Diversity index) and Firmicutes/Bacteroidetes (F/B) ratio upon AOM/DSS treatment in ORX mice was significantly decreased by TP supplementation. The ratio of commensal bacteria to opportunistic pathogens was lower in the TP-administered females and ORX mice than in the AOM/DSS group. Opportunistic pathogens (Mucispirillum schaedleri or Akkermansia muciniphila) were identified only in the TP group. In addition, microbial diversity and F/B ratio were higher in male controls than in female and ORX controls. Flintibacter butyricus, Ruminococcus bromii, and Romboutsia timonensis showed similar changes in the male control group as those in the female and ORX controls.

CONCLUSION

In conclusion, testosterone determines the dysbiosis of gut microbiota, which suggests that it plays a role in the sex-related differences in colorectal carcinogenesis.

Systems biology approach reveals a common molecular basis for COVID-19 and non-alcoholic fatty liver disease (NAFLD)

Background

Patients with non-alcoholic fatty liver disease (NAFLD) may be more susceptible to coronavirus disease 2019 (COVID-19) and even more likely to suffer from severe COVID-19. Whether there is a common molecular pathological basis for COVID-19 and NAFLD remains to be identified. The present study aimed to elucidate the transcriptional alterations shared by COVID-19 and NAFLD and to identify potential compounds targeting both diseases.

Methods

Differentially expressed genes (DEGs) for COVID-19 and NAFLD were extracted from the GSE147507 and GSE89632 datasets, and common DEGs were identified using the Venn diagram. Subsequently, we constructed a protein–protein interaction (PPI) network based on the common DEGs and extracted hub genes. Then, we performed gene ontology (GO) and pathway analysis of common DEGs. In addition, transcription factors (TFs) and miRNAs regulatory networks were constructed, and drug candidates were identified.

Results

We identified a total of 62 common DEGs for COVID-19 and NAFLD. The 10 hub genes extracted based on the PPI network were IL6, IL1B, PTGS2, JUN, FOS, ATF3, SOCS3, CSF3, NFKB2, and HBEGF. In addition, we also constructed TFs–DEGs, miRNAs–DEGs, and protein–drug interaction networks, demonstrating the complex regulatory relationships of common DEGs.

Conclusion

We successfully extracted 10 hub genes that could be used as novel therapeutic targets for COVID-19 and NAFLD. In addition, based on common DEGs, we propose some potential drugs that may benefit patients with COVID-19 and NAFLD.

Combination treatment with 17β-estradiol and anti-PD-L1 suppresses MC38 tumor growth by reducing PD-L1 expression and enhancing M1 macrophage population in MC38 colon tumor model

17β-estradiol (E2) is known to have a protective effect in colorectal cancer (CRC); thus, E2 may be effective for cancer immunotherapy in CRC. The aim of this study is to evaluate the effect of combination therapy with E2 and anti-programmed cell death receptor-1 ligand (PD-L1) antibodies, and the effects of sex and estrogen on colon tumor growth, PD-L1 expression, and tumor-associated cell populations in an MC38 colon tumor model. Male mice showed increased MC38 colon tumor growth and PD-L1 expression in tumor sections as well as higher proportion of cancer-associated fibroblasts (CD45^-CD31^-CD140a⁺), PD-L1-expressing tumor cells (CD45^-CD274⁺) and tumor-associated macrophages (TAMs) (CD11b⁺F4/80⁺CD274⁺) compared to female mice. E2 treatment prior to MC38 injection significantly reduced these phenomena in male mice. Furthermore, co-treatment with E2 and anti-PD-L1 antibodies significantly inhibited MC38 tumor growth and reduced PD-L1-expressing cells in male mice compared to treatment with either E2 or anti-PD-L1 antibodies alone. Combination treatment with E2 and anti-PD-L1 decreased TAM population (CD11b⁺F4/80⁺) in the tumor mass while increasing M1 TMAs (CD11b⁺F4/80⁺CD86⁺). These results suggest that estrogen inhibits MC38 tumor growth by downregulating PD-L1 expression and regulating tumor-associated cell populations. Furthermore, estrogen boosted the effect of anti-PD-L1 antibody in the MC38 tumor model.

Lactobacillus paracasei BD5115-Derived 2-Hydroxy-3-Methylbutyric Acid Promotes Intestinal Epithelial Cells Proliferation by Upregulating the MYC Signaling Pathway

Metabolites of probiotics that are beneficial to human health have been isolated from the intestinal tract and natural dairy products. However, many studies on probiotics and prebiotics are limited to the observation of human cohorts and animal phenotypes. The molecular mechanisms by which metabolites of probiotics regulate health are still need further exploration. In this work, we isolated a strain of Lactobacillus Paracasei from human milk samples. We numbered it as Lactobacillus Paracasei BD5115. The mouse model of high-fat diet confirmed that the metabolites of this strain also promotes intestinal epithelial cells (IECs) proliferation. Single-cell sequencing showed that a bZIP transcription factor MAFF was specifically expressed in some IECs. We found that MAFF interacted with MBP1 to regulate the expression of MYC. Analysis of the active components in BD5115 metabolites confirmed that 2-hydroxy-3-methylbutyric acid promotes the expression of the MYC gene. This promotes the proliferation of IECs. Our findings indicate that 2-hydroxy-3-methylbutyric acid regulate MYC gene expression mediated by MAFF/MBP1 interaction. This study not only screened a strain with promoted IECs proliferation, but also discovered a new signal pathway that regulates MYC gene expression.

A novel targeted approach to delineate a role for estrogen receptor-β in ameliorating murine mammary tumor-associated neuroinflammation

PURPOSE

Circulating estrogens in breast cancer patients and survivors are often extremely low due to menopause and estrogen-reducing cancer treatments. Simultaneously, circulating inflammatory markers, and inflammatory proteins in brains of rodent tumor models, can be elevated and correlate with debilitating neurological and psychological comorbidities. Because estrogen has anti-inflammatory properties in the brain, we hypothesized that mammary tumor-induced neuroinflammation is driven, in part, by reduced brain estrogen signaling.

METHODS

An ovariectomized mouse model of postmenopausal breast cancer utilizing the ERα-positive 67NR mammary tumor cell line was used for these experiments. A novel, orally bioavailable, and brain penetrant ERβ agonist was administered daily via oral gavage. Following treatment, estrogen-responsive genes were measured in brain regions. Central and circulating inflammatory markers were measured via RT-qPCR and a multiplex cytokine array, respectively.

RESULTS

We present novel findings that peripheral mammary tumors alter estrogen signaling genes including receptors and aromatase in the hypothalamus, hippocampus, and frontal cortex. Mammary tumors induced peripheral and central inflammation, however, pharmacological ERβ activation was not sufficient to reduce this inflammation.

CONCLUSIONS

Data presented here suggest that compensating for low circulating estrogen with ERβ brain activation is not sufficient to attenuate mammary tumor-induced neuroinflammation, and is therefore not a likely candidate for the treatment of behavioral symptoms in patients. The novel finding that mammary tumors alter estrogen signaling-related genes is a clinically relevant advancement to the understanding of how peripheral tumor biology modulates neurobiology. This is necessary to predict and prevent behavioral comorbidities (e.g., cognitive impairment) prevalent in cancer patients and survivors.

Association of Type 1 diabetes with ulcerative colitis in BALB/c mice: Investigations on sex-specific differences

Diabetes comorbidity in ulcerative colitis (UC) has relevant clinical and therapeutic implications. The link between hyperglycemia and intestinal barrier function with respect to infection and inflammation consequences exists in diabetes. The present study was designed to decipher the molecular mechanisms associated with Type 1 Diabetes mellitus and the UC in both male and female BALB/c mice. Dextran sulfate sodium (DSS; 2.5%w/v) dissolved in drinking water was given for three cycles (each cycle; 7 days) with 7 days recovery period in-between to both male and female BALB/c mice. At the first recovery period, Streptozotocin (40 mg/kg; i.p.) was administered for 5 consecutive days in the case of male BALB/c mice; whereas the same procedure was repeated at the beginning of each recovery period in female animals. In the DSS + DB group of male animals, disease activity index, myeloperoxidase activity, nitrite level, plasma lipopolysaccharides, interleukin-1β, histological score, % fibrotic area, % TUNEL positive cells were significantly increased. Furthermore, protein expression of phosphorylated nuclear factor kappa light chain enhancer of activated B cells (pNFκB65), proliferating cell nuclear antigen, interleukin-6, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and cysteine-containing aspartate-specific proteases-1 (caspase-1) significantly increased in the DSS + DB group of male animals as compared to female. The present study findings proved that hyperglycemic conditions exacerbated the pathological conditions in UC of male animals; whereas milder conditions developed in females.

Estrogen Receptors in Colorectal Cancer: Facts, Novelties and Perspectives

Colorectal cancer (CRC) is the second cause of cancer-related death in both sexes worldwide. As pre-menopausal women are less likely to develop CRC compared to age-matched men, a protective role for estrogens has been hypothesized. Indeed, two isoforms of nuclear estrogen receptors (ER) have been described: ERα and ERβ. While the binding of 17beta-estradiol to ERα activates anti-apoptotic pathways, the interaction with ERβ activates caspase-3, inducing apoptosis. In this regard, several pieces of evidence show that ERβ tends to be under-regulated in advanced adenomas and CRC, with an opposite trend for ERα. Furthermore, ERβ stimulation slows adenomatous polyp growth and modulates relevant CRC pathways. Based on such considerations, dietary modulation of ER is promising, particularly in subjects with genetic predisposition for CRC. Nevertheless, the main limitation is the lack of clinical trials on a large population scale.

The complex interplay of gut microbiota with the five most common cancer types: From carcinogenesis to therapeutics to prognoses

The association between human gut microbiota and cancers has been an evolving field of biomedical research in recent years. The gut microbiota is composed of the microorganisms residing in the gastrointestinal system that interact with the host to regulate behaviours and biochemical processes within the gut. This symbiotic physiological interaction between the gut and the microbiota plays a significant role in the modulation of gut homeostasis, in which perturbations to the microbiota, also known as dysbiosis can lead to the onset of diseases, including cancer. In this review, we analysed the current literature to understand the role of gut microbiota in the five most prevalent cancer types, namely colon (colorectal), lung, breast, prostate, and stomach cancers. Recent studies have observed the immunomodulatory and anti-tumoural effects of gut microbiota in cancers. Furthermore, gut microbial dysbiosis can induce the release of toxic metabolites and exhibit pro-tumoural effects in the host. The gut microbiota was observed to have clinical implications in each cancer type in addition to regulating the efficacy of standard chemotherapy and natural anticancer agents. However, further research is warranted to understand the complex role of gut microbiota in the prevention, diagnosis, treatment, and prognoses of cancer.

The Enhanced Inhibitory Effect of Estrogen on PD-L1 Expression Following Nrf2 Deficiency in the AOM/DSS Model of Colitis-Associated Cancer

Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a dual role in carcinogenesis. We previously reported that Nrf2 deficiency enhances the anti-tumorigenic effect of 17β-estradiol (E2) in an azoxymethane (AOM)/dextran sodium sulfate (DSS) model of colitis-associated cancer (CAC). Herein, we aimed to determine a possible explanation for our recent work and investigated the immune microenvironment represented by programmed death-ligand 1 (PD-L1) expression. One week after the AOM injection, mice were administered with DSS in drinking water for seven days; daily E2 injections were intraperitoneally administered during this period. The mice were sacrificed 16 weeks after AOM injection and analyzed for PD-L1 expression in the distal colon tissues using Western blotting and immunohistochemistry (IHC). Based on Western blotting results, PD-L1 expression was reduced in Nrf2 knockout (KO) female and E2-treated male mice when compared with their wild-type counterparts, following AOM/DSS treatment; this supports the association of PD-L1 expression with tumor progression. Additionally, this finding was in good agreement with the IHC results for PD-L1. Furthermore, we observed that PD-L1 is predominantly expressed in stromal cells rather than on epithelial cells in the colon. Western blotting revealed that PD-L1 expression in the colon positively correlates with expressions of inducible nitric oxide synthase (iNOS) (male, P = 0.002; female, P <0.001) and cyclooxygenase-2 (COX-2) (male, P <0.001; female, P <0.001). Collectively, our findings indicate that estrogen ameliorates the immune microenvironment represented by PD-L1 expression and enhances its effect in the absence of Nrf2.

Changes in Microbial Community Composition Related to Sex and Colon Cancer by Nrf2 Knockout

The frequency of azoxymethane/dextran sulfate sodium (AOM/DSS)-induced carcinogenesis in male mice is higher than that in female mice. Previous studies have reported that 17β-estradiol inhibits tumorigenesis in males by modulating nuclear factor-erythroid 2-related factor 2 (Nrf2). This study aimed to investigate the changes in mouse gut microbiome composition based on sex, AOM/DSS-induced colorectal cancer (CRC), and Nrf2 genotype. The gut microbiome composition was determined by 16S rRNA gene sequencing fecal samples obtained at week 16 post-AOM administration. In terms of sex differences, our results showed that the wild-type (WT) male control mice had higher alpha diversity (i.e. Chao1, Shannon, and Simpson) than the WT female control mice. The linear discriminant analysis effect size (LEfSe) results revealed that the abundances of Akkermansia muciniphila and Lactobacillus murinus were higher in WT male control mice than in WT female controls. In terms of colon tumorigenesis, the alpha diversity of the male CRC group was lower than that of the male controls in both WT and Nrf2 KO, but did not show such changes in females. Furthermore, the abundance of A. muciniphila was higher in male CRC groups than in male controls in both WT and Nrf2 KO. The abundance of Bacteroides vulgatus was higher in WT CRC groups than in WT controls in both males and females. However, the abundance of L. murinus was lower in WT female CRC and Nrf2 KO male CRC groups than in its controls. The abundance of A. muciniphila was not altered by Nrf2 KO. In contrast, the abundances of L. murinus and B. vulgatus were changed differently by Nrf2 KO depending on sex and CRC. Interestingly, L. murinus showed negative correlation with tumor numbers in the whole colon. In addition, B. vulgatus showed positive correlation with inflammatory markers (i.e. myeloperoxidase and IL-1β levels), tumor numbers, and high-grade adenoma, especially, developed mucosal and submucosal invasive adenocarcinoma at the distal part of the colon. In conclusion, Nrf2 differentially alters the gut microbiota composition depending on sex and CRC induction.

Inhibition of the NRF2/KEAP1 Axis: A Promising Therapeutic Strategy to Alter Redox Balance of Cancer Cells

Significance: The nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1 (NRF2/KEAP1) pathway is a crucial and highly conserved defensive system that is required to maintain or restore the intracellular homeostasis in response to oxidative, electrophilic, and other types of stress conditions. The tight control of NRF2 function is maintained by a complex network of biological interactions between positive and negative regulators that ultimately ensure context-specific activation, culminating in the NRF2-driven transcription of cytoprotective genes. Recent Advances: Recent studies indicate that deregulated NRF2 activation is a frequent event in malignant tumors, wherein it is associated with metabolic reprogramming, increased antioxidant capacity, chemoresistance, and poor clinical outcome. On the other hand, the growing interest in the modulation of the cancer cells' redox balance identified NRF2 as an ideal therapeutic target. Critical Issues: For this reason, many efforts have been made to identify potent and selective NRF2 inhibitors that might be used as single agents or adjuvants of anticancer drugs with redox disrupting properties. Despite the lack of specific NRF2 inhibitors still represents a major clinical hurdle, the researchers have exploited alternative strategies to disrupt NRF2 signaling at different levels of its biological activation. Future Directions: Given its dualistic role in tumor initiation and progression, the identification of the appropriate biological context of NRF2 activation and the specific clinicopathological features of patients cohorts wherein its inactivation is expected to have clinical benefits, will represent a major goal in the field of cancer research. In this review, we will briefly describe the structure and function of the NRF2/ KEAP1 system and some of the most promising NRF2 inhibitors, with a particular emphasis on natural compounds and drug repurposing. Antioxid. Redox Signal. 34, 1428-1483.

Testosterone strongly enhances azoxymethane/dextran sulfate sodium-induced colorectal cancer development in C57BL/6 mice

Colorectal cancer (CRC) is known to occur more frequently in males than in females, with sex hormones reportedly influencing the development. The purpose of the study was to investigate whether orchiectomy in C57BL/6 male mice reduces colorectal tumorigenesis and whether testosterone administration increases tumorigenesis after orchiectomy in an azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model. Clinical symptoms, including colitis and tumor incidence, were evaluated in the absence or presence of testosterone in AOM/DSS-treated male, as well as orchiectomized (ORX) male and female mice. The levels of serum testosterone and colonic myeloperoxidase, interleukin (IL)-1β, and IL-6 were measured by ELISA. Target mRNA expression was assessed by quantitative real-time PCR. Orchiectomy significantly diminished the AOM/DSS-induced colitis indices, including disease activity index, colon shortening, and histological severity at week 2, and decreased tumor numbers and incidence rates in the distal part of the colon increased following AOM/DSS administration at week 13; this reduction was reversed by testosterone supplementation. Furthermore, it was confirmed that the ELISA level (MPO and IL-1β) and the mRNA expression of the inflammatory mediators (COX-2 and iNOS) were maintained at high levels in the tumors of the testosterone-treated group compared with AOM/DSS groups. Interestingly, both endogenous and exogenous testosterone administrations were associated with tumor development (> 2 mm in size) and submucosal invasive cancer. Based on multivariate logistic regression analysis, testosterone was identified as a reasonable hazard factor for the progression of submucosal invasive cancer of the distal colon. In conclusion, endogenous and exogenous testosterone presented a stimulating effect on AOM/DSS-induced colitis and carcinogenicity.

Nuclear Factor Erythroid 2-related Factor 2 Knockout Suppresses the Development of Aggressive Colorectal Cancer Formation Induced by Azoxymethane/Dextran Sulfate Sodium-Treatment in Female Mice

Colon tumors develop more frequently in male than in female. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays differential roles in the stage of tumorigenesis. The purpose of this study was to investigate the role of Nrf2 on colitis-associated tumorigenesis using Nrf2 knockout (KO) female mice. Azoxymethane (AOM) and dextran sulfate sodium (DSS)-treated wild-type (WT) and Nrf2 KO female mice were sacrificed at week 2 and 16 after AOM injection. Severity of colitis, tumor incidence, and levels of inflammatory mediators were evaluated in AOM/DSS-treated WT and Nrf2 KO mice. Furthermore, qRT-PCR, Western blot abnalysis, and ELISA were performed in colon tissues. At week 2, AOM/DSS-induced colon tissue damages were significantly greater in Nrf2 KO than in WT mice. At week 16, tumor numbers (> 2 mm size) were significantly lower in both the proximal and distal colon in Nrf2 KO compared to WT. The overall incidences of adenoma/cancer of the proximal colon and submucosal invasive cancer of the distal colon were reduced by Nrf2 KO. The mRNA and protein expression levels of NF-κB-related mediators (i.e., iNOS and COX-2) and Nrf2-related antioxidants (i.e., heme oxygenase-1 and glutamate-cysteine ligase catalytic subunit) were significantly lower in the Nrf2 KO than in WT mice. Interestingly, the protein level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) was higher in AOM/DSS-treated Nrf2 KO than in WT mice. Our results support the oncogenic effect of Nrf2 in the later stage of carcinogenesis and upregulation of tumor suppressor 15-PGDH might contribute to the repression of colitis-associated tumorigenesis in Nrf2 KO female mice.

LASS2 mediates Nrf2-driven progestin resistance in endometrial cancer

Progestin administration serves as the optimal conservative treatment method for women with endometrial cancer or precancer lesions who want to preserve fertility. However, there are still at least 30% of patients in which progestin resistance occurs. LASS2 (Ceramide Synthase 2) has been reported to be involved in chemotherapy resistance, whether it also plays a role in progestin resistance is not clear. Here, we explored the detailed mechanism by which Nrf2/LASS2 contributes to progestin resistance and disease progression.

METHODS

IHC assays were performed to estimate the expression pattern of Nrf2 and LASS2. Moreover, it bears three antioxidant response elements (ARE) in the promoter region of LASS2 gene, therefore, Luciferase assays were performed to determine if Nrf2 regulates LASS2 by binding with these ARE sequence. Western Blot assays were used to determine the expression of Nrf2 and LASS2 protein among various endometrial cell lines. Relative mRNA expression levels were detected by RT-PCR. Cellular growth was monitored with CCK-8 tests. Apoptosis was determined with Annexin V-PI staining and flow cytometry analysis. siRNA knockdown was performed to investigate the effects of Nrf2 on cell proliferation.

RESULT

Nrf2/LASS2 is highly expressed in endometrial cancer tissue, as compared to expression levels in normal endometrial tissue. Proliferation assays demonstrated that overexpression of Nrf2/LASS2 resulted in progestin resistance. Conversely, knockdown of LASS2 increased apoptosis and decreased cell viability. In addition, metformin overcame progestin resistance by down-regulating Nrf2/LASS2 expression.

CONCLUSION

Our findings provide new insight into the mechanism of progestin resistance in type I endometrial cancer. Nrf2/LASS2 may not only be a possible marker for predicting the prognosis of endometrial cancer but also serve as a potential therapeutic target.

Endogenous sex steroid hormones and colorectal cancer risk: a systematic review and meta-analysis

Preclinical data suggest that endogenous sex steroid hormones may be implicated in colorectal cancer (CRC) development, however, findings from epidemiological studies are conflicting. The aim of this systematic review and meta-analysis was to investigate the associations between endogenous concentrations of sex hormones and CRC risk. PubMed and Scopus were searched until June 2020 for prospective studies evaluating the association between pre-diagnostic plasma/serum concentrations of estradiol, testosterone and sex-hormone binding globulin (SHBG) and CRC risk. Summary relative risks (RRs) and 95% confidence intervals (CIs) were estimated using the inverse-variance weighted random-effects model based on the DerSimonian-Laird estimator. Eight studies were included in the meta-analysis after evaluating 3,859 non-duplicate records. Four of the eight studies had a nested case-control design, one study was a case-cohort and the rest three studies were cohort studies, and they included on average 295 cases (range:48-732) and 2,105 controls. No associations were found for endogenous sex steroid hormones in men or post-menopausal women with CRC risk, with evidence for substantial heterogeneity observed among women. Findings from this meta-analysis do not support presence of associations between pre-diagnostic concentrations of testosterone, estradiol and SHBG with incident CRC risk in men and post-menopausal women.

Using systems medicine to identify a therapeutic agent with potential for repurposing in inflammatory bowel disease

Inflammatory bowel diseases (IBDs) cause significant morbidity and mortality. Aberrant NF-κB signalling is strongly associated with these conditions, and several established drugs influence the NF-κB signalling network to exert their effect. This study aimed to identify drugs that alter NF-κB signalling and could be repositioned for use in IBD. The SysmedIBD Consortium established a novel drug-repurposing pipeline based on a combination of in silico drug discovery and biological assays targeted at demonstrating an impact on NF-κB signalling, and a murine model of IBD. The drug discovery algorithm identified several drugs already established in IBD, including corticosteroids. The highest-ranked drug was the macrolide antibiotic clarithromycin, which has previously been reported to have anti-inflammatory effects in aseptic conditions. The effects of clarithromycin effects were validated in several experiments: it influenced NF-κB-mediated transcription in murine peritoneal macrophages and intestinal enteroids; it suppressed NF-κB protein shuttling in murine reporter enteroids; it suppressed NF-κB (p65) DNA binding in the small intestine of mice exposed to lipopolysaccharide; and it reduced the severity of dextran sulphate sodium-induced colitis in C57BL/6 mice. Clarithromycin also suppressed NF-κB (p65) nuclear translocation in human intestinal enteroids. These findings demonstrate that in silico drug repositioning algorithms can viably be allied to laboratory validation assays in the context of IBD, and that further clinical assessment of clarithromycin in the management of IBD is required.This article has an associated First Person interview with the joint first authors of the paper.

17β-Estradiol strongly inhibits azoxymethane/dextran sulfate sodium-induced colorectal cancer development in Nrf2 knockout male mice

Nuclear factor erythroid 2-related factor 2 (Nrf2) has dual effects on inflammation and cancer progression depending on the microenvironment. Estrogens have a protective effect on colorectal cancer (CRC) development. The aim of this study was to investigate CRC development in Nrf2 knockout (KO) mice. Azoxymethane (AOM) and dextran sulfate sodium (DSS)-treated wild-type (WT) and Nrf2 KO male mice were sacrificed at weeks 2 and 16 after AOM injection with/without 17β-estradiol (E2) treatment during week 1. Disease activity index and colon tissue damage at week 2 showed strong attenuation following E2 administration in WT mice but to a lesser extent in Nrf2 KO male mice. At week 16, E2 significantly diminished AOM/DSS-induced adenoma/cancer incidence at distal colon in the Nrf2 KO group, but not in the WT. Furthermore, mRNA or protein levels of NF-κB-related mediators (i.e., iNOS, TNF-α, and IL-1β) and Nrf2-related antioxidants (i.e., NQO1 and HO-1) were significantly lower in the Nrf2 KO group regardless of E2 treatment compared to the WT. The expression of estrogen receptor beta (ERβ) was higher in the Nrf2 KO group than in the WT. In conclusion, estrogen further inhibits CRC by upregulating ERβ-related alternate pathways in the absence of Nrf2.

High-fat diet and estrogen impacts the colon and its transcriptome in a sex-dependent manner

There is a strong association between obesity and colorectal cancer (CRC), especially in men, whereas estrogen protects against both the metabolic syndrome and CRC. Colon is the first organ to respond to high-fat diet (HFD), and estrogen receptor beta (ERβ) can attenuate CRC development. How estrogen impacts the colon under HFD and related sex differences has, however, not been investigated. To dissect this, mice were fed control diet or HFD for 13 weeks and administered receptor-selective estrogenic ligands for the last three weeks. We recorded impact on metabolism, colon crypt proliferation, macrophage infiltration, and the colon transcriptome. We found clear sex differences in the colon transcriptome and in the impact by HFD and estrogens, including on clock genes. ERα-selective activation reduced body weight and generated systemic effects, whereas ERβ-selective activation had local effects in the colon, attenuating HFD-induced macrophage infiltration and epithelial cell proliferation. We here demonstrate how HFD and estrogens modulate the colon microenvironment in a sex- and ER-specific manner.

A Holistic View of Berberine Inhibiting Intestinal Carcinogenesis in Conventional Mice Based on Microbiome-Metabolomics Analysis

Berberine (BBR) has been reported that it has effects on inhibiting colorectal cancer (CRC). However, the mechanism of BBR on CRC also remains largely unknown. Herein, we investigated the therapeutic effects of BBR on CRC from the perspective of gut microbiota and metabolic alterations, which can provide a holistic view to understand the effects of BBR on CRC. First, azoxymethane (AOM)/dextran sodium sulfate (DSS) mouse was used as CRC animal model, then the degree of colorectal carcinogenesis in AOM/DSS mice with or without BBR administration was measured. The composition and abundance of gut microbiota was investigated by using 16S rRNA. Meanwhile, feces samples were analyzed with ¹H NMR spectroscopy to investigate the metabolic alterations. As a result, BBR significantly reduced intestinal tumor development with lower macroscopic polyps and ki-67 expression of intestinal tissue, and better colonic morphology in mice. Moreover, BBR altered the composition of gut microbiota in AOM/DSS mice obviously, which were characterized by a decrease of Actinobacteria and Verrucomicrobia significantly at the phylum level. At the genus level, it was able to suppress pathogenic species, such as f_Erysipelotrichaceae, Alistipes, and elevate some short-chain fatty acids (SCFA)-producing bacteria, including Alloprevotella, Flavonifractor, and Oscillibacter. Metabolic data further revealed that BBR induced metabolic changes in feces focus on regulating glycometabolism, SCFA metabolism and amino acid metabolism, which also provides evidence for alteration of the microbiota because these feces metabolites are the products of interactions between the host and the microbial community. This study showed that BBR induced alterations in microbiota and metabolic in AOM/DSS mice, which might providing new insight into the inhibition effects of BBR on CRC.

Intestinal estrogen receptor beta suppresses colon inflammation and tumorigenesis in both sexes

Estrogen hormones protect against colorectal cancer (CRC) and a preventative role of estrogen receptor beta (ERβ) on CRC has been supported using full knockout animals. However, it is unclear through which cells or organ ERβ mediates this effect. To investigate the functional role of intestinal ERβ during colitis-associated CRC we used intestine-specific ERβ knockout mice treated with azoxymethane and dextran sodium sulfate, followed by ex vivo organoid culture to corroborate intrinsic effects. We explored genome-wide impact on TNFα signaling using human CRC cell lines and chromatin immunoprecipitation assay to mechanistically characterize the regulation of ERβ. Increased tumor formation in males and tumor size in females was noted upon intestine-specific ERβ knockout, accompanied by enhanced local expression of TNFα, deregulation of key NFκB targets, and increased colon ulceration. Unexpectedly, we noted especially strong effects in males. We corroborated that intestinal ERβ protects against TNFα-induced damage intrinsically, and characterized an underlying genome-wide signaling mechanism in CRC cell lines whereby ERβ binds to cis-regulatory chromatin areas of key NFκB regulators. Our results support a protective role of intestinal ERβ against colitis-associated CRC, proposing new therapeutic strategies.

17β-Estradiol supplementation changes gut microbiota diversity in intact and colorectal cancer-induced ICR male mice

The composition of the gut microbiota is influenced by sex hormones and colorectal cancer (CRC). Previously, we reported that 17β-estradiol (E2) inhibits azoxymethane/dextran sulfate sodium (AOM/DSS)-induced tumorigenesis in male mice. Here, we investigated whether the composition of the gut microbiota is different between male and female, and is regulated by estrogen as a secondary outcome of previous studies. We established four groups of mice based on the sex and estrogen status [ovariectomized (OVX) female and E2-treated male]. Additionally, three groups of males were established by treating them with AOM/DSS, and E2, after subjecting them to AOM/DSS treatment. The mice were sacrificed at 21 weeks old. The composition of the gut microbiota was analyzed using 16S rRNA metagenomics sequencing. We observed a significant increase in the microbial diversity (Chao1 index) in females, males supplemented with E2, and males treated with AOM/DSS/E2 compared with normal males. In normal physiological condition, sex difference and E2 treatment did not affect the ratio of Firmicutes/Bacteroidetes (F/B). However, in AOM/DSS-treated male mice, E2 supplementation showed significantly lower level of the F/B ratio. The ratio of commensal bacteria to opportunistic pathogens was higher in females and E2-treated males compared to normal males and females subjected to OVX. Unexpectedly, this ratio was higher in the AOM/DSS group than that determined in other males and the AOM/DSS/E2 group. Our findings suggest that estrogen alters the gut microbiota in ICR (CrljOri:CD1) mice, particularly AOM/DSS-treated males, by decreasing the F/B ratio and changing Shannon and Simpson index by supply of estrogen. This highlights another possibility that estrogen could cause changes in the gut microbiota, thereby reducing the risk of developing CRC.

17β-Estradiol reduces inflammation and modulates antioxidant enzymes in colonic epithelial cells

BACKGROUND/AIMS

Estrogen is known to have protective effect in colorectal cancer development. The aims of this study are to investigate whether estradiol treatment reduces inflammation in CCD841CoN, a female human colonic epithelial cell line and to uncover underlying mechanisms of estradiol effects.

METHODS

17β-Estradiol (E2) effect was measured by Western blot after inducing inf lammation of CCD841CoN by tumor necrosis factor α (TNF-α). Expression levels of estrogen receptor α (ERα) and β (ERβ), cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), heme oxygenase-1 (HO-1), and NAD(P)H-quinone oxidoreductase-1 (NQO-1) were also evaluated.

RESULTS

E2 treatment induced expression of ERβ but did not increase that of ERα. E2 treatment for 48 hours significantly elevated the expression of anti-oxidant enzymes, HO-1 and NQO-1. TNF-α treatment significantly increased the level of activated NF-κB (p < 0.05), and this increase was significantly suppressed by treatment of 10 nM of E2 (p < 0.05). E2 treatment ameliorated TNF-α-induced COX-2 expression and decrease of HO-1 expression. 4-(2-phenyl-5,7-bis(trifluoromethyl) pyrazolo(1,5-a)pyrimidin-3-yl)phenol (PHTPP), antagonist of ERβ, removed the inhibitory effect of E2 in the TNF-α-induced COX-2 expression (p = 0.05).

CONCLUSION

Estrogen seems to inhibit inflammation in female human colonic epithelial cell lines, through down-regulation of NF-κB and COX-2 expression and induction of anti-oxidant enzymes such as HO-1 and NQO-1.