BreastDefend enhances effect of tamoxifen in estrogen receptor-positive human breast cancer in vitro and in vivo

DNA damages in hepatocytes are amended by an inflammation-driven rescue repair mechanism in chronic hepatitis B

BACKGROUND

Our previous study has shown that intrahepatic necroinflammation favors the eliminations of HBV integration and clonal hepatocytes. Here, the effect of inflammation on host DNA damage eliminations in liver biopsy tissues from patients with chronic hepatitis B (CHB) was further investigated.

METHODS

DNA damage markers, histone γ-H2AX and phosphorylated heterochromatin protein 1γ (p-HP1γ), and senescent marker p21 were detected using immunohistochemical and immunofluorescent assays in liver biopsy samples from 69 CHB patients and 12 liver cirrhosis (LC) patients. Twenty paired hepatocellular carcinoma (HCC) surgical samples were used as controls.

RESULTS

Both γ-H2AX and p-HP1γ were sensitively detected in nuclear and cytoplasmic/nuclear patterns. Nuclear γ-H2AX was superior as a DNA damage marker in hepatocytes. The level of nuclear γ-H2AX in CHB, comparable to those in LC and HCC, was correlated with liver fibrosis and coexisted with the senescent marker p21. However, hepatocytes carried an alleviated level of DNA damages, which was associated with the level of cytoplasmic γ-H2AX. Cytoplasmic γ-H2AX chiefly occurred in hepatocytes near necroinflammatory foci, was correlated with liver inflammation and usually indicated the decrease or disappearance of nuclear γ-H2AX. The lack of cytoplasmic γ-H2AX together with the high level of nuclear γ-H2AX was associated with the progression from large cell changes/dysplasia to small cell changes/dysplasia.

CONCLUSIONS

Hepatocytes in CHB already carry massive DNA damages and undergo cellular senescence. The DNA damages in those senescent hepatocytes are histopathologically demonstrated to be amended by a novel cytoplasmic γ-H2AX-indicated and inflammation-driven rescue repair mechanism, which may be involved in hepatocarcinogenesis if it works improperly.

Interactions Between Natural Products and Tamoxifen in Breast Cancer: A Comprehensive Literature Review

Introduction: Tamoxifen (TAM) is the most commonly used hormone therapeutic drug for the treatment of estrogen receptor-positive (ER+) breast cancer. 30%–70% of clinical breast cancer patients use natural products, which may increase the likelihood of drug interactions.

Objective: To evaluate the evidence for the interactions between natural products and TAM in breast cancer.

Methods: Electronic databases, including PubMed, CINAHL Plus (via EbscoHost), European PMC, Medline, and Google Scholar, were searched for relevant publications. The search terms include complementary and alternative medicine, natural products, plant products, herbs, interactions, tamoxifen, breast cancer, and their combinations.

Results: Various in vitro and in vivo studies demonstrated that the combined use of natural products with TAM produced synergistic anti-cancer effects, including improved inhibition of tumor cell growth and TAM sensitivity and reduced side effects or toxicity of TAM. In contrast, some natural products, including Angelica sinensis (Oliv.) Diels [Apiaceae], Paeonia lactiflora Pall., Rehmannia glutinosa (Gaertn.) DC., Astragalus mongholicus Bunge, and Glycyrrhiza glabra L. [Fabaceae], showed estrogen-like activity, which may reduce the anti-cancer effect of TAM. Some natural products, including morin, silybin, epigallocatechin gallate (EGCG), myricetin, baicalein, curcumin, kaempferol, or quercetin, were found to increase the bioavailability of TAM and its metabolites in vivo. However, three are limited clinical studies on the combination of natural products and TAM.

Conclusion: There is evidence for potential interactions of various natural products with TAM in pre-clinical studies, although the relevant clinical evidence is still lacking. Further studies are warranted to evaluate the potential interactions of natural products with TAM in clinical settings.

Regulation of aromatase in cancer

The regulation of aromatase, an enzyme involved in the biosynthesis of estrogen in normal and cancer cells, has been associated with growth factor signaling and immune response modulation. The tissue-specific regulatory roles of these factors are of particular importance as local aromatase expression is strongly linked to cancer development/progression and disease outcomes in patients. Therefore, aromatase has become a chemotherapeutic target and aromatase inhibitors (AIs) are used in the clinic for treating hormone-dependent cancers. Although AIs have shown promising results in the treatment of cancers, the emerging increase in AI-resistance necessitates the development of new and improved targeted therapies. This review discusses the role of tumor and stromal-derived growth factors and immune cell modulators in regulating aromatase. Current single-agent and combination therapies with or without AIs targeting growth factors and immune checkpoints are also discussed. This review highlights recent studies that show new connections between growth factors, mediators of immune response, and aromatase regulation.

Hydroxycitric acid potentiates the cytotoxic effect of tamoxifen in MCF-7 breast cancer cells through inhibition of ATP citrate lyase

Hydroxycitric acid (HCA), a dietary-derived weight loss supplement, competitively inhibits ATP citrate lyase (ACLY). Tamoxifen (TAM) is the most frequently used therapy for estrogen receptor (ER)-positive breast cancer patients, but its application was restricted due to efficacy related issues. Lipid metabolic reprogramming plays a key role in cancer progression and response to treatment. This study will test the hypothesis that targeting lipid metabolic enzymes could enhance TAM effect against breast cancer cells. MCF-7 ER-positive breast cancer cell line was used, and the cytotoxic effect of TAM treatment, alone and in combination with HCA was evaluated. Flowcytometric analysis of apoptosis following TAM and/or HCA treatment was additionally performed. Besides, the effects of TAM and/or HCA on ACLY, acetyl CoA carboxylase alpha (ACC-α) and fatty acid synthase (FAS) expression were investigated. Likewise, expression of ER-α protein through TAM and/or HCA treatment was examined. Cell contents of cholesterol and triglyceride were quantified. Treatment with TAM or HCA significantly reduced cell viability in a concentration-dependent manner whereas co-treatment synergistically reduced cell viability, promoted apoptosis, and decreased the expression of ACLY, ACC-α, and FAS. Intracellular triglyceride and cholesterol were accumulated in response to treatment with TAM and/or HCA. Moreover, either solitary TAM or TAM/ HCA co-treatment increased ER-α protein levels non significantly. Our results revealed that TAM effects on breast cancer are mediated, in part, through the regulation of key genes involved in lipid metabolism. Accordingly, inhibition of ACLY by HCA might be beneficial to enhance the therapeutic index of TAM against breast cancer.

Improving breast cancer therapy using doxorubicin loaded solid lipid nanoparticles: Synthesis of a novel arginine-glycine-aspartic tripeptide conjugated, pH sensitive lipid and evaluation of the nanomedicine in vitro and in vivo

Breast cancer is the leading cause of cancer mortality in women worldwide. To overcome the toxic side effects and multidrug resistance (MDR) during doxorubicin (DOX) chemotherapy, an arginine-glycine-aspartic (RGD) tripeptide modified, pH-sensitive solid lipid nanoparticles (SLNs) is employed in this study. In this study, a RGD conjugated, pH sensitive lipid was synthesized using glycerin monostearate (GMS) and adipic acid dihydrazide (HZ) as lipid materials and named RGD-HZ-GMS. RGD-HZ-GMS was applied to encapsulate DOX to construct a RGD modified, DOX loaded SLNs (RGD-DOX-SLNs). To evaluate the anticancer effect of RGD-DOX-SLNs, breast cancer cell line (MCF-7 cells) and DOX resistant cell line (MCF-7/ADR cells) were used. in vivo tumor suspension and toxicity effects were evaluated on mice bearing MCF-7/ADR cells breast cancer model. RGD-DOX-SLNs had a uniformly spherical shape. The mean particle size and zeta potential of the RGD-DOX-SLNs was 96.3 nm and 35.6 mV, respectively. RGD-DOX-SLNs showed 5.58 fold higher area under the plasma concentration - time curve (AUC) compared with DOX solution. Terminal half life (T_1/2) and peak concentration (C_max) of RGD-DOX-SLNs was 10.85 h and 39.12 ± 2.71 L/kg/h. in vitro and in vivo antitumor results indicate that RGD-DOX-SLNs might be a promising novel lipid carrier which could improve breast cancer therapy.

Prevention of Tamoxifen-related Nonalcoholic Fatty Liver Disease in Breast Cancer Patients

BACKGROUND

Tamoxifen is commonly used to prevent breast cancer recurrence. Studies have confirmed the association between tamoxifen and nonalcoholic fatty liver disease (NAFLD), with the results indicating the need for aggressive management of this side effect. We assessed the potential risk factors for and identified the possible protective factors of tamoxifen-related fatty liver.

MATERIALS AND METHODS

We enrolled patients with a history of breast cancer, aged 20 to 70 years, who had received with tamoxifen treatment within the past 5 years. We obtained the initial data and performed a follow-up blood test and ultrasound examination to compare the differences before and after tamoxifen treatment. The patients were divided into relatively normal and fatty liver groups.

RESULTS

Of the 266 enrolled tamoxifen-treated patients, 143 (53.8%) and 123 (46.2%) were in the relatively normal and fatty liver groups, respectively. The initial body weight (57.6 ± 9.3 kg vs. 60.9 ± 10.3 kg; P = .006) and body mass index (BMI; 23.4 ± 3.8 kg/m² vs. 25.0 ± 4.2 kg/m²; P < .001) were lower in the relatively normal group. An initial BMI of ≥ 22 kg/m² was a potential risk factor for tamoxifen-related NAFLD (hazard ratio [HR], 1.58; 95% confidence interval [CI], 1.00-2.48; P = .048). In contrast, a weekly exercise duration of ≥ 150 minutes reduced the risk (HR, 0.47; 95% CI, 0.31-0.69; P < .001).

CONCLUSION

The results from our study suggest that a BMI of ≥ 22 kg/m² is a potential risk factor for tamoxifen-related fatty liver and exercise is a possible protective factor.