Possible Gender-Related Modulation by the ROCK1 Gene in Colorectal Cancer Susceptibility

The Therapeutic Potential of Milk Extracellular Vesicles on Colorectal Cancer

Colorectal cancer remains one of the leading prevalent cancers in the world and is the fourth most common cause of death from cancer. Unfortunately, the currently utilized chemotherapies fail in selectively targeting cancer cells and cause harm to healthy cells, which results in profound side effects. Researchers are focused on developing anti-cancer targeted medications, which is essential to making them safer, more effective, and more selective and to maximizing their therapeutic benefits. Milk-derived extracellular vesicles (EVs) from camels and cows have attracted much attention as a natural substitute product that effectively suppresses a wide range of tumor cells. This review sheds light on the biogenesis, methods of isolation, characterization, and molecular composition of milk EVs as well as the therapeutic potentials of milk EVs on colorectal cancer.

Binding between ROCK1 and DCTN2 triggers diabetes‑associated centrosome amplification in colon cancer cells

Type 2 diabetes increases the risk various types of cancer and is associated with a poor prognosis therein. There is also evidence that the disease is associated with cancer metastasis. Centrosome amplification can initiate tumorigenesis with metastasis in vivo and increase the invasiveness of cancer cells in vitro. Our previous study reported that type 2 diabetes promotes centrosome amplification via the upregulation and centrosomal translocation of Rho-associated protein kinase 1 (ROCK1), which suggests that centrosome amplification is a candidate biological link between type 2 diabetes and cancer development. In the present study, functional proteomics analysis was used to further investigate the molecular pathways underlying centrosome amplification by targeting ROCK1 binding partners. High glucose, insulin and palmitic acid were used to induce centrosome amplification, and immunofluorescent staining was employed to visualize centrosomal alterations. Combined with immunoprecipitation, mass spectrometry-based proteomics analysis was used to identify ROCK1 binding proteins, and protein complex disruption was achieved by siRNA-knockdown. In total, 1,148 ROCK1 binding proteins were identified, among which 106 proteins were exclusively associated with the treated samples, 193 were only associated with the control samples, and 849 were found in both the control and treated samples. Of the proteins with evidence of centrosomal localization, Dynactin subunit 2 (DCTN2) was confirmed to be localized to the centrosomes. Treating the cells with high glucose, insulin and palmitic acid increased the protein levels of ROCK1 and DCTN2, promoted their binding with each other, and triggered centrosome amplification. Disruption of the protein complex by knocking down ROCK1 or DCTN2 expression partially attenuated centrosome amplification, while simultaneous knockdown of both proteins completely inhibited centrosome amplification. These results suggested ROCK1-DCTN2 binding as a signal for the regulation of centrosome homeostasis, which is key for diabetes-associated centrosome amplification, and enriches our knowledge of centrosome biology. Therefore, the ROCK1-DCTN2 complex may serve as a target for inhibiting centrosome amplification both in research or future therapeutic development.

The Survival Advantage of Females at Premenopausal Age Is Race Dependent in Colorectal Cancer

Background

A female prognostic advantage in younger individuals has been demonstrated in various cancers. Several large-scale analyses based on different racial backgrounds have reported inconsistent results in colorectal cancer. The aim of the present study was to evaluate the prognostic value of sex and age in patients with colorectal cancer of different ethnic groups.

Methods

We identified 71,812 eligible patients from the Surveillance, Epidemiology and End Results database. According to age at diagnosis, the patients were categorized into premenopausal age (≤45 yrs), menopausal age (46–54 yrs), and postmenopausal age (≥55 yrs) subgroups for further analysis.

Results

Multivariate analysis identified the female survival advantage to be significant in the premenopausal age subgroup (P = 0.002, HR (95% CI): 0.73 (0.60–0.89)), diminished in the menopausal age subgroup (P = 0.09), and absent in the postmenopausal age subgroup (P = 0.96). Furthermore, the female survival advantage at premenopausal age was significant only in white patients (P = 0.001, HR (95% CI): 0.68 (0.54–0.87)) and not in either American Indian/Alaska Native or Asian or Pacific Islander patients. There was a trend of better survival of females in black patients (P = 0.07).

Conclusions

Sex was a major prognostic factor in colorectal cancer patients, especially premenopausal women, and the difference was also associated with race.

Milk Exosomes Prevent Intestinal Inflammation in a Genetic Mouse Model of Ulcerative Colitis: A Pilot Experiment

Background

Milk is rich in nutrients and anabolic mediators rendering it essential for postnatal growth and metabolic programming. However, in adults, excessive consumption of milk is controversial as civilization disorders such as diabetes or prostate cancer may be promoted. A cytoprotective effect of milk could be utilized in inflammatory conditions, that is, chronic colitis.

Objective

To evaluate the effect of bovine milk exosomes on intestinal inflammation in a genetic mouse model of ulcerative colitis.

Methods

Intestinal-specific kindlin 2 knockout (KO) mice were exposed for 4 days to tamoxifen for induction of an ulcerative colitis phenotype. At the same time 4 other kindlin 2 KO mice were exposed to 33 μg/g cow milk derived exosomes in PBS by oral gavage. Both groups were compared to untreated wild-type controls.

Results

Milk exosomes prevented the appearance of a severe ulcerative phenotype. The macroscopic colitis score dropped from a mean of 3.33 in untreated mice to 0.75 index points (p < 0.01) in exosome-treated mice, which included significant improvement of the subscores of stool improvement and colon weight and length. Treated mice featured a noninflamed appearance of the intestinal mucosa.

Key Message

Milk exosomes have cytoprotective/anti-inflammatory activity in a genetic mouse model of ulcerative colitis. The mechanisms behind this need to be elucidated. This pilot study needs verification before a therapeutic strategy is developed.

Sex disparities in cancer

Sex is a key biological factor affecting the development of many cancer types. There are considerable differences between male and female subpopulations in terms of cancer incidence, prognosis and mortality. Recent studies have extensively characterized the sex-biased molecular changes in cancer patients. Further efforts should be made to develop sex-specific cancer prevention and therapeutic strategies.

Exosomes of pasteurized milk: potential pathogens of Western diseases

Milk consumption is a hallmark of western diet. According to common believes, milk consumption has beneficial effects for human health. Pasteurization of cow's milk protects thermolabile vitamins and other organic compounds including bioactive and bioavailable exosomes and extracellular vesicles in the range of 40-120 nm, which are pivotal mediators of cell communication via systemic transfer of specific micro-ribonucleic acids, mRNAs and regulatory proteins such as transforming growth factor-β. There is compelling evidence that human and bovine milk exosomes play a crucial role for adequate metabolic and immunological programming of the newborn infant at the beginning of extrauterine life. Milk exosomes assist in executing an anabolic, growth-promoting and immunological program confined to the postnatal period in all mammals. However, epidemiological and translational evidence presented in this review indicates that continuous exposure of humans to exosomes of pasteurized milk may confer a substantial risk for the development of chronic diseases of civilization including obesity, type 2 diabetes mellitus, osteoporosis, common cancers (prostate, breast, liver, B-cells) as well as Parkinson's disease. Exosomes of pasteurized milk may represent new pathogens that should not reach the human food chain.

Melatonin inhibits colon cancer RKO cell migration by downregulating Rho‑associated protein kinase expression via the p38/MAPK signaling pathway

Melatonin is predominately produced and secreted by the pineal gland, and inhibits cell growth in various cancer cell lines such as colorectal cancer. However, the precise mechanisms involved have not been fully elucidated. In the present study, the potential molecular mechanism underlying the efficacy of melatonin on migration in RKO colon cancer cells was investigated. The effects of melatonin and H-1152, a selective inhibitor of Rho-associated protein kinase (ROCK), on the migration of RKO cells were analyzed by an in vitro wound healing assay. The localization of zonula occludens-1 (ZO-1) and occludin were observed by immunofluorescence. Reverse transcription-quantitative polymerase chain reaction (qPCR) was performed to analyze the relative mRNA levels of ROCK, ZO-1 and occludin. In addition, western blot analysis was implemented to examine the expression of ROCK, phospho (p)-myosin phosphatase targeting subunit 1 (MYPT1), p-myosin light chains (MLC) and p-p38. The results revealed that the expression levels of ROCK2, p-MYPT1 and p-MLC in RKO cells were decreased, and the membrane protein expression of ZO-1 and occludin increased when the cells were treated with melatonin. qPCR demonstrated that melatonin downregulated ROCK2 gene expression, and upregulated the expression of the ZO-1 and occludin genes. The levels of ZO-1 and occludin localized in the tight junctions were markedly increased in the immunofluorescence assay. In addition, the phosphorylation levels of p38 were reduced when the cells were treated with melatonin, and treatment with H-1152 downregulated p38 phosphorylation. The results indicated that melatonin may inhibit the migration of RKO colon cancer cells by downregulating ROCK expression via the p38/mitogen-activated protein kinase signaling pathway.