Obesity and cancer stem cells: Roles in cancer initiation, progression and therapy resistance

Adipocyte-conditioned medium induces tamoxifen resistance by activating PI3K/Akt/mTOR pathway in estrogen receptor-positive breast cancer cells

Resistance to endocrine therapy is a major clinical challenge in estrogen receptor (ER)-positive breast cancer. Obesity is associated with the clinical response to ER-positive breast cancers; however, the mechanism underlying obesity-induced resistance to endocrine therapy in ER-positive breast cancers remains unclear. In this study, we investigated the molecular mechanisms underlying obesity-induced resistance to tamoxifen (TAM), an anti-estrogen agent, in the ER-positive breast cancer cell line MCF-7 using differentiated adipocyte-conditioned medium (D-CM). Treatment of the cells with D-CM promoted TAM resistance by reducing TAM-induced apoptosis. The expression levels of the ERα target genes were higher in D-CM-treated cells than those in untreated ones. In contrast, when the cells were cultured in the presence of TAM, the expression levels were decreased, with or without D-CM. Moreover, the expression of the markers for cancer stem-like cells (CSCs) and mammosphere formation was enhanced by co-treating with D-CM and TAM, compared with TAM alone. The phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway was activated in MCF-7 cells by D-CM treatment, even in the presence of TAM. Inhibition of the PI3K/Akt/mTOR pathway decreased the expression levels of the CSC markers, suppressed mammosphere formation, and resensitized to TAM via inducing apoptosis in D-CM-treated cells. These results indicate that the conditioned medium of differentiated adipocytes promoted TAM resistance by inducing the CSC phenotype through activation of the PI3K/Akt/mTOR pathway in ER-positive breast cancer cells. Thus, the PI3K/Akt/mTOR pathway may be a therapeutic target in obese patients with ER-positive breast cancers.

Take metabolic heterogeneity into consideration when applying dietary interventions to cancer therapy: A review

In recent years, dietary interventions have attracted much attention in cancer therapy. Mechanistic studies suggest that dietary interventions can inhibit the progression of cancer through deprivation of essential metabolites, lowering the levels of protumor hormones, activation of anticancer immunity and synergistic effects with conventional anticancer therapies. The feasibility, safety and promising tumor outcomes have also been established in humans. However, the results from both preclinical and clinical studies are inconsistent or even conflicting, the reasons for which have not been extensively considered. In this review, we discuss the various heterogeneity, including dietary protocols, tissue of origin and cancer locations, spatial and temporal metabolic heterogeneity, and divergent combination treatment, that may affect the responses of different cancers to dietary interventions. Understanding this heterogeneity and taking them into consideration when applying dietary interventions to cancer therapy will allow us to deliver the right diet to the right patient at the right time to maximize compliance, safety and efficacy of conventional anticancer therapy and to improve the outcomes of patients with cancer.

Effect of skinfold thickness on arm venous access port in cancer patients

BACKGROUND

Currently, skinfold thickness in studies on arm venous access ports and the effect of venous access port application are unknown.

MATERIALS AND METHODS

A total of 256 cancer patients who underwent primary venous access port placement in the Fourth Hospital of Hebei Medical University from September 2022 to March 2023 were selected as the study subjects. Two hundred fifty-six patients were divided into normal skinfold thickness group and high skinfold thickness group according to skinfold thickness. The success rate of primary catheterization of arm venous port catheterization, catheterization operation time, catheterization length and incidence rate of adverse reactions were compared.

RESULTS

There was no significant difference in the basic data between the two groups. There was no significant difference in the success rate of primary catheterization between the two groups (p > 0.05), the catheterization operation time in the normal skinfold thickness group was significantly lower than that in the high skinfold thickness group (p < 0.05), the total length of the implanted catheter in the normal skinfold thickness group was significantly lower than that in the high skinfold thickness group (p < 0.05), and the incidence of adverse reactions in the normal skinfold thickness group was significantly lower than that in the high skinfold thickness group (p < 0.05).

CONCLUSION

In cancer patients, skinfold thickness can significantly affect the application effect of arm venous port, and normal skinfold thickness for arm venous port has shorter operation time, total length of implanted catheter and lower incidence of adverse reactions.