Tamoxifen Group Research Articles

Rapid Reductions in Breast Density following Tamoxifen Therapy as Evaluated by Whole-Breast Ultrasound Tomography.

Purpose: Women whose mammographic breast density declines within 12–18 months of initiating tamoxifen for chemoprevention or adjuvant treatment show improved therapeutic responses compared with those whose density is unchanged. We tested whether measuring changes in sound speed (a surrogate of breast density) using ultrasound tomography (UST) could enable rapid identification of favorable responses to tamoxifen. Methods: We evaluated serial density measures at baseline and at 1 to 3, 4 to 6, and 12+ months among 74 women (aged 30–70 years) following initiation of tamoxifen for clinical indications, including an elevated risk of breast cancer (20%) and diagnoses of in situ (39%) or invasive (40%) breast carcinoma, enrolled at Karmanos Cancer Institute and Henry Ford Health System (Detroit, MI, USA). For comparison, we evaluated an untreated group with screen negative mammography and frequency-matched on age, race, and menopausal status (n = 150), at baseline and 12 months. Paired t-tests were used to assess differences in UST sound speed over time and between tamoxifen-treated and untreated patients. Results: Sound speed declined steadily over the 12 month period among patients receiving tamoxifen (mean (SD): −3.0 (8.2) m/s; p = 0.001), whereas density remained unchanged in the untreated group (mean (SD): 0.4 (7.1) m/s; p = 0.75 (relative change between groups: p = 0.0009)). In the tamoxifen group, we observed significant sound speed reductions as early as 4–6 months after tamoxifen initiation (mean (SD): −2.1 (6.8) m/s; p = 0.008). Sound speed reductions were greatest among premenopausal patients (P-interaction = 0.0002) and those in the middle and upper tertiles of baseline sound speed (P-interaction = 0.002). Conclusions: UST can image rapid declines in sound speed following initiation of tamoxifen. Given that sound speed and mammographic density are correlated, we propose that UST breast imaging may capture early responses to tamoxifen, which in turn may have utility in predicting therapeutic efficacy.

Lipid Changes During Endocrine Therapy in Breast Cancer Patients: The Results of a 5-Year Real-World Retrospective Analysis.

BackgroundThe aim of this study was to investigate the status of serum lipids during endocrine therapy.MethodsWe retrospectively analysed lipid profiles during the 5-year treatment of 1487 consecutive postoperative BC patients. Lipid parameters included triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C). Those biomarkers were measured at baseline and 1, 2, 3, 4 and 5 years following the initiation of endocrine therapy.ResultsFor premenopausal BC patients, LDL levels rapidly decreased at 1 year in the tamoxifen (TAM) group compared with baseline levels (p<0.05), and this decline remained for the following 4 years. Additionally, LDL levels were significantly lower in the TAM group than in the nonendocrine group at all assessment time points (p<0.05). Similarly, TC levels also decreased in the TAM group compared with baseline levels at all assessment time points (p<0.05), and compared with the levels in the nonendocrine group, TC levels were also lower for the first 4 years. For postmenopausal BC patients, there was no significant difference in the lipid profiles (TG, TC, LDL and HDL) in the letrozole (LET), anastrozole (ANA) or exemestane (EXE) groups compared with the nonendocrine group. For patients who received TAM, compared with the nonendocrine group, TC levels decreased at 1 year, and LDL levels decreased at 1 and 2 years.ConclusionsTAM may improve LDL and TC levels in premenopausal BC patients. In postmenopausal BC patients, aromatase inhibitors (AIs) may have no adverse effects on lipid profiles, and TAM may have limited beneficial effects on serum lipids.

Effect of Preventive Acupunture Combined with CMNS6-1 Electroacupuncture Instrument on Promoting Apoptosis of 7,12-Dimethylbenzene (a) Anthracene-Induced Breast Cancer Model Rats

The purpose of this study was to evaluate the effect of preventive acupuncture combined with CMNS6-1 electroacupuncture on 7,12-dimethylbenzanthracene induced mammary tumors in Sprague-Dawley rats and to explore the effect of preventive acupuncture on mammary tumors from the perspective of apoptosis. 48 w old female Sprague-Dawley rats were randomly divided into control (10), model (10), tamoxifen (10) and preventive acupuncture (10) groups. The model group, tamoxifen group and preventive acupuncture group were administered once intragastrically with 100 mg/kg body weight of 7,12-dimethylbenzanthracene to induce spontaneous breast cancer. On d 1 after modeling, acupuncture plus electrical stimulation was administered to the preventive acupuncture group. Density wave was selected for electrical stimulation with a frequency of 2 Hz/100 Hz and an intensity of 1 mA and three acupoints, "Zu San Li", "San Yin Jiao" and "Tan Zhong", were stimulated for 20 min per treatment, once every other day, three times a week for 16 w. Tamoxifen (3 mg/kg body weight, intragastrically, every day) was started the day after 7,12-dimethylbenzanthracene administration and continued for 16 w, as positive control treatment. Apoptosis of breast tumor tissue cells was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and expression of caspase-3 and B-cell lymphoma-2 was assessed by immunohistochemistry. During the experiment, no tumors were detected in rats from the control+sham group, all the rats in the 7,12-dimethylbenzanthracene+sham group developed tumors and the cumulative incidence of tumors was 100 %, meanwhile the cumulative incidence of tumors in the 7,12-dimethylbenzanthracene+preventive acupuncture group and the 7,12-dimethylbenzanthracene+tamox group were 60 % and 50 %, respectively. Terminal deoxynucleotidyl transferase dUTP nick-end labeling assay showed that preventive acupuncture could significantly promote apoptosis in breast tumor cells in 7,12-dimethylbenzanthracene induced rat, while increased the expression levels of pro-apoptotic proteins such as caspase-3 and B-cell lymphoma-2 associated X. The expression level of antiapoptotic protein B-cell lymphoma-2 was down-regulated and the ratio of B-cell lymphoma-2/B-cell lymphoma-2 associated X was increased. Preventive acupuncture therapy combined with CMNS6-1 electroacupuncture instrument inhibited 7,12-dimethylbenzanthracene-induced mammary tumorigenesis in rats and the mechanism may be related to the regulation of apoptosis-related protein expression and promotion of tumor cell apoptosis.

Role of Curculigo Orchioides in the Proliferation and Apoptosis of Breast Cancer Michigan Cancer Foundation-7 (MCF-7) Cells Under Network Pharmacology

Based on network pharmacology (NP), the effects of curculigo orchioides (CO) granules alone or CO granules along with tamoxifen on the proliferation and apoptosis (P&amp;A) of human breast cancer (BC) cells were explored. A search database was constructed to obtain the active components (ACs) of CO and related target genes to perform disease mapping, and a BC target map was constructed to perform related pathway enrichment analysis (PEA). The blank control group (CG), estrogen group (EG), and tamoxifen group (TG) were set as controls to observe the effects of CO granules alone and CO granules along with tamoxifen. The PEA showed that the effect of CO on BC may be related to the cooperation of its ACs. The target of action may be related to cell cycle and proliferation, growth factors, metabolic pathways, etc. Different concentrations of CO had different effects, CO granules of various concentrations had no obvious growth-promoting effect (P &lt; 0.05), and so did CO combined with tamoxifen (P &gt; 0.05); high-dose (H-D) CO combined with tamoxifen can induce cell apoptosis (P &lt; 0.05). Through NP, the ACs of CO and related targets of BC were predicted and analyzed. At the same time, it was proved that CO granules are safe in clinical use, and the combined effect of tamoxifen is better in the treatment of estrogen-positive patients, providing reference for the follow-up use of CO in the treatment of BC.

Hydroethanolic Extract of Defatted Buchholzia coriacea Seeds Alleviates Tamoxifen-Induced Hepatic Triglyceride Accumulation, Inflammation and Oxidative Distress in Rat.

Background: Tamoxifen (TMX) has proven to be effective in the prevention and treatment of breast cancer. However, long-term use of TMX is associated with hepatic steatosis, oxidative liver injury and hepatocarcinoma. Buchholzia coriacea seeds (BCS) have been widely applied in traditional medicine due to their nutritional and therapeutic potentials. This study investigates the protective effect of hydroethanolic extract of (defatted) B. coriacea seeds (HEBCS) against TMX–induced hepatotoxicity in rats. Methods: Thirty-six (36) male albino rats were divided into six groups (n = 6/group). Group I served as control. Group II received 50 mg/kg/day TMX orally (p.o.) (TMX) for 21 days, group III received TMX plus 125 mg/kg/d HEBCS p.o. (HEBCS 125) for 21 days, group IV received TMX plus 250 mg/kg/d HEBCS p.o. (HEBCS 250) for 21 days and rats in group V and VI received HEBCS 125 and HEBCS 250 respectively for 21 days. Results: Compared with the control, TMX caused a significant increase (p < 0.05) in serum hepatic function biomarkers: alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase by 57%, 60% and 68% respectively. TMX also caused a significant increase in hepatic triglycerides level by 166% when compared with control and a significant decrease in serum HDL-cholesterol level by 37%. Compared with control, hepatic marker of inflammation, tumour necrosis factor alpha (TNF-α) increased significantly by 220%, coupled with significant increase in expression of interleukin 6 and cyclooxygenase 2. There was also significant increase in levels of Biomarkers of oxidative stress, nitric oxide, malondialdehyde and protein carbonyls in the TMX group by 89%, 175% and 114% respectively when compared with the control. Hepatic antioxidants, reduced glutathione (GSH) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST) and glutathione peroxidase (GSH-Px) decreased significantly in the TMX group by 35%, 67%, 41%, 59% and 53% respectively when compared with the control. However, HEBCS at 250 mg/kg significantly protected against TMX–induced hepatotoxicity by decreasing hepatic triglyceride content, serum hepatic function biomarkers, hepatic inflammation and oxidative stress with significant improvement in hepatic antioxidant system. Histopathological findings show that HEBCS alleviate TMX–induced hepatocyte ballooning. Conclusions: Current data suggest that HEBCS protected against TMX–induced hepatotoxicity in rats. HEBCS may be useful in managing TMX–induced toxicities in breast cancer patients. It may also be helpful against other forms of liver injury involving steatosis, inflammation, free radicals, and oxidative damage.

Kolaviron pre-treatment suppresses 7, 12 dimethylbenzanthracene-induced alterations in estrogen receptor-α, CYP 1A1, oxidative stress and inflammation in female Wistar rats.

Due to the need to develop locally available, cheaper, and efficacious treatment regimens for breast cancer, the chemopreventive effect of kolaviron (KV), an extract of Garcinia kola seeds was examined. Fifty (50) female Wistar rats (120-180g) were assigned to five groups (control group, 7, 12 dimethylbenzanthracene [DMBA] groups, tamoxifen group) of 10 rats each. They were pre-treated with KV thrice a week for four weeks except control. Estrogen receptor-α (ER-α) levels were determined in the pre-treated rats before induction of mammary carcinogenesis. After the four weeks pre-treatment period, 80mg/kg of DMBA was used for induction. A hundred and fifty (150) days after induction, the rats were sacrificed humanely. Significantly higher levels of ER-α, formation of lobular neoplastic cells, epithelial hyperplasia, lymphocyte infiltration, increased cytokines (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]), CYP1A1 activity and malondialdehyde (MDA) with a corresponding decrease in superoxide dismutase (SOD), catalase and glutathione peroxidase were observed in DMBA-induced rats. Pre-treatment with KV at 200mg/kg body weight significantly (p<.05) decreased ER-α levels by 19.01% and 37.52%, [IL-6] by 36.37% and 20.55%, TNF-α by 42.2% and 12.33% in serum and mammary tissue respectively. Also, a significant (p<.05) decrease in serum CYP1A1 activity, MDA with concomitant increase in SOD, catalase and glutathione peroxidase activities were observed in serum and mammary tissue respectively. Collectively, the results suggest that KV could be further explored in targeting chemoprevention of DMBA-induced mammary damage. PRACTICAL APPLICATIONS: Garcinia kola is widely cultivated in West and Central Africa with kolaviron (KV) as its major constituents. The seeds which have a bitter astringent taste are widely consumed by people in the region. Locals claim that consumption of the seeds provides relief for the management of several ailments including cancer. However, scientific investigations that provide a basis for these claims are still needed. This study provides evidence that points to the ameliorative potential of KV on breast cancer model. The results will be beneficial to local communities who hitherto had no knowledge on the potential of G. kola in chemoprevention. The results from this study will also attract further research attention from the international scientific community to examine the anti-cancer benefits of G. kola. This will also be beneficial to the global community due to the increasing number of breast cancer cases recorded annually.

The Effects of Endocrine Therapies on Lipid Profiles in Chinese Young Women With Early Breast Cancer.

This study aimed to evaluate and compare the effects of various endocrine therapies on lipid profiles in young patients with breast cancer. A retrospective, single-center study was performed to investigate the effects of tamoxifen (TAM), tamoxifen plus ovarian function suppression (TAM+OFS), and aromatase inhibitors plus ovarian function suppression (AI+OFS) on lipid profiles during the 60 months of endocrine therapy in hormone receptor-positive patients aged <40 with early breast cancer. The primary endpoint was the cumulative incidence of lipid events, and the secondary endpoints were the changes in lipid profiles. A total of 230 young patients were included with the mean age of 35.7 years old. The patients in TAM group had significantly lower incidence of 5-year lipid events than those in TAM+OFS group (7.4% versus 21.3%; P=0.016) and AI+OFS group (7.4% versus 21.6%; P=0.009). The incidence of fatty liver was significantly higher in TAM+OFS group than TAM group (52.5%versus 30.9%; P=0.043). Lipid events were associated with younger age (odds ratio (OR)=0.865, 95% confidence interval (CI): 0.780-0960; P=0.006), higher baseline LDL-C (OR=14.959, 95% CI: 4.379-51.105; P<0.001), and use of OFS (OR=3.557, 95% CI: 1.151-10.989; P=0.027). Therefore, application of OFS, with younger age and higher baseline LDL-C, may increase the incidence of lipid events in premenopausal breast cancer. More care should be taken for lipid profiles during the endocrine therapy for young breast cancer patients.

Mammographic density, endocrine therapy and breast cancer risk: a prognostic and predictive biomarker review.

Mammographic density, endocrine therapy and breast cancer risk: a prognostic and predictive biomarker review.

Regorafenib or Tamoxifen for platinum-sensitive recurrent ovarian cancer with rising CA125 and no evidence of clinical or RECIST progression: A GINECO randomized phase II trial (REGOVAR)

ObjectiveTo evaluate the efficacy and safety of regorafenib versus tamoxifen in platinum-sensitive ovarian cancer biological recurrence, defined by CA-125 increase without radiological (RECIST criteria) or symptomatic evidence of progression. Patients and methods116 patients with platinum-sensitive ovarian cancer presenting an isolated increase of CA-125 were planned to be randomized. Regorafenib was administered orally at 160 or 120 mg daily, 3 weeks on/1 week off or tamoxifen at 40 mg daily, until disease progression or development of unacceptable toxicity. The primary endpoint was Progression-Free Survival, assessed by progression according to RECIST 1.1 or death (by any cause). Secondary endpoints included Overall Survival, Best Response and CA-125 response rate. Results68 patients were randomized. Median age was 67 years (range: 30–87). Primary site of cancer was ovarian for most patients (92.6%). Tumors were predominantly serous / (89.7%), high grade (83.6%) and initial FIGO staging was III for 69.6% of the patients. Most (79.4%) patients were included after the first line of platinum-based treatment. After a median follow-up of 32 months, there was no difference of progression-free survival (PFS) between regorafenib and tamoxifen groups (p = 0.72), with median PFS of 5.6 months (CI 90%: 3.84–7.52) for the tamoxifen arm and 4.6 months (CI 90%: 3.65–7.33) for the regorafenib arm. There was also no difference in term of overall survival, best response or CA-125 response, delay to next therapy. Regorafenib presented a less favorable safety profile than tamoxifen, with grade 3/4 events occurring for 90.9% of the patients compared to 54.3% for tamoxifen. The most frequent were cutaneous, digestive, and biological events. Notably, hand-foot syndrome occurred in 36.4% of these patients. ConclusionRegorafenib presented an unfavorable toxicity profile compared to tamoxifen, with no superior efficacy in this population of patients.

Quality of Life in an e-Cohort of Women Treated by Endocrine Therapy for Early Breast Cancer

ObjectiveThe objective of our study was to analyze quality of life (QOL) in an e-cohort of patients treated for breast cancer (BC) by endocrine therapy (ET), by means of validated quality of life questionnaires. Study design and settingA retrospective, observational, e-cohort study was conducted (Seintinelles platform). Female patients treated for nonmetastatic and nonrecurrent BC, treated in France after 2005, filled in online questionnaires concerning: QOL (QLQ-C30 and QLQ-BR23), tolerability of treatment and demographic characteristics. A multivariate analysis including variables significant on univariate analysis (P < .05) to select QOL predictors was performed. ResultsWe included 1,198 patients, 1140 of whom declared that they were taking ET (37.7% tamoxifen, 17.1% aromatase inhibitor (AI), 5.6% LHRH-agonist and 39.6% sequential tamoxifen and AI). Different tolerability profiles were observed when comparing the tamoxifen and AI groups. Treatment adherence was similar in the 2 groups. QOL varied slightly according to the type of ET. On multivariate analysis, ET had no impact on QOL. However, individual patient characteristics (socioeconomic, education and age) were significantly associated with QOL ConclusionUsing a real-life study questionnaire on a large e-cohort, individual patient characteristics were strongly associated with deterioration of QOL. The use of e-cohorts must be encouraged to modulate the conclusions of randomized trials.

The Utility of SOX2 and AGR2 Biomarkers as Early Predictors of Tamoxifen Resistance in ER-Positive Breast Cancer Patients.

Background Despite the undeniable benefit of tamoxifen therapy for ER-positive breast cancer patients, approximately one-third of those patients either do not respond to tamoxifen or develop resistance. Thus, it is a crucial step to identify novel, reliable, and easily detectable biomarkers indicating resistance to this drug. Objective The aim of this work is to explore SOX2 and AGR2 biomarker expression in the tumor tissue of ER-positive breast cancer patients in combination with the evaluation of serum AGR2 level of these patients in order to validate these biomarkers as early predictors of tamoxifen resistance. Methods This study was conducted on 224 ER-positive breast cancer patients. All patients were primarily subjected to serum AGR2 levelling by ELISA and their breast cancer tissue immunostained for SOX2 and AGR2. After 5 years of follow-up, the patients were divided into 3 groups: group 1 was tamoxifen sensitive and groups 2 and 3 were tamoxifen resistant. Time to failure of tamoxifen treatment was considered the time from the beginning of tamoxifen therapy to the time of discovery of breast cancer recurrence or metastases (in months). Results SOX2 and AGR2 biomarkers expression and serum AGR2 level were significantly higher in groups 2 and 3 in comparison to group 1, while the relationship between Her2 neu expression and Ki67 index in the 3 different groups was statistically nonsignificant. Lower SOX2 and AGR2 expression and low AGR2 serum levels in the studied patients of groups 2 and 3 were significantly associated with longer time-to-failure of tamoxifen treatment. According to the ROC curve, the combined use of studied markers validity was with a sensitivity of 100%, specificity of 96%, PPV 96%, and NPV 100% (p < 0.001; AUC: 0.984). Conclusions Integrated use of SOX2 and AGR2 biomarkers with serum AGR2 assay holds a promising hope for their future use as predictive markers for early detection of tamoxifen resistance in ER-positive breast cancer patients.

Oestradiol promotes the intrahepatic bile duct development of C57BL/6CrSlc mice during embryonic period via Notch signalling pathway.

Oestradiol (E2) is a critical factor for multiple systems' development during the embryonic period. Here, we aimed to investigate the effects of oestradiol on intrahepatic bile duct development, which may allow a better understanding of congenital bile duct dysplasia. DLK+ hepatoblasts were extracted from the C57BL/6CrSlc foetal mice and randomly divided into control group, oestradiol groups (1, 10, 100 nM) and oestradiol (10 nM) + DAPT (inhibitor of Notch signalling; 40 µM) group for in vitro experiments. For in vivo analysis, pregnant mice were divided into control group, oestradiol (intraperitoneal injection of 0.6 mg/kg/day) ± DAPT (subcutaneous injection of 10 mg/kg/day) groups and tamoxifen (gavage administration of 0.4 mg/kg/day) group. The results showed that oestradiol promoted hepatoblast differentiation into cholangiocytes and intrahepatic bile duct development during the embryonic period. Tamoxifen, an antioestrogenic drug, inhibited the above processes. Moreover, oestradiol promoted the expression of Notch signalling pathway‐associated proteins and genes both in vitro and in vivo. Notably, DAPT addition inhibited the oestradiol‐mediated effects. In conclusion, oestradiol can promote hepatoblast differentiation into cholangiocytes and intrahepatic bile duct development of C57BL/6CrSlc mice during embryonic period via the Notch signalling pathway.

Investigating the role of endogenous estrogens, hormone replacement therapy, and blockade of estrogen receptor-\u03b1 activity on breast metabolic signaling

PurposeMenopause is associated with an increased risk of estrogen receptor-positive (ER +) breast cancer. To characterize the metabolic shifts associated with reduced estrogen bioavailability on breast tissue, metabolomics was performed from ovary-intact and ovariectomized (OVX) female non-human primates (NHP). The effects of exogenous estrogen administration or estrogen receptor blockade (tamoxifen treatment) on menopause-induced metabolic changes were also investigated.MethodsBilateral ovariectomies were performed on female cynomolgus macaques (Macaca fascicularis) to model menopause. OVX NHP were then divided into untreated (n = 13), conjugated equine estrogen (CEE)-treated (n= 13), or tamoxifen-treated (n = 13) subgroups and followed for 3 years. Aged-matched ovary-intact female NHP (n = 12) were used as a premenopausal comparison group. Metabolomics was performed on snap-frozen breast tissue.ResultsChanges in several different metabolic biochemicals were noted, particularly in glucose and fatty acid metabolism. Specifically, glycolytic, Krebs cycle, acylcarnitines, and phospholipid metabolites were elevated in breast tissue from ovary-intact NHP and OVX + CEE in relation to the OVX and OVX + tamoxifen group. In contrast, treatment with CEE and tamoxifen decreased several cholesterol metabolites, compared to the ovary-intact and OVX NHP. These changes were accompanied by elevated bile acid metabolites in the ovary-intact group.ConclusionAlterations in estrogen bioavailability are associated with changes in the mammary tissue metabolome, particularly in glucose and fatty acid metabolism. Changes in these pathways may represent a bioenergetic shift in gland metabolism at menopause that may affect breast cancer risk.

Breast Cancer Prevention: Time for Change.

Agency breast cancer prevention guidelines for other than hereditary cancers have not materially changed in 20 years; endocrine-targeted agents (then, tamoxifen; now, adding raloxifene and aromatase inhibitors) reduce good prognosis estrogen receptor (ER)-positive, progesterone receptor (PR)-positive cancers without reducing deaths from breast cancer. Across three tamoxifen placebo-controlled prevention trials (N = 23,360) begun almost 30 years ago, although there were 226 fewer breast cancer cases, there were nine more deaths from breast cancer in the tamoxifen groups. Following clinical advances, currently more than half of breast cancer cases are solved problems with extremely low risk of death. As endocrine-targeted agents commonly prevent these cancers, widespread implementation of current prevention strategies may not reduce deaths from breast cancer. Compared with other breast cancers, ER-positive, PR-negative cancers and triple-negative cancers have inferior survival (90.6% v 83.8% v 78.1%, respectively; P < .001). Against this background, in the Women's Health Initiative Dietary Modification randomized trial (N = 48,835), ER-positive, PR-negative cancers were statistically significantly reduced in the intervention group (hazard ratio, 0.77; 95% CI, 0.64 to 0.94) and deaths from breast cancer were reduced 21% (P = .02). In the Women's Health Initiative randomized, placebo-controlled trial evaluating conjugated equine estrogen (N = 10,739), ER-positive, PR-negative cancers were statistically significantly reduced in the intervention group (hazard ratio, 0.44; 95% CI, 0.27 to 0.74) and deaths from breast cancer were reduced 40% (P = .04). These findings suggest that reexamination of breast cancer risk reduction strategies and clinical practice is needed.

The Synergistic Effects of Celastrol in combination with Tamoxifen on Apoptosis and Autophagy in MCF-7 Cells.

Breast cancer is one of the most common cancers among females and is associated with high mortality and morbidity rates. Several studies have demonstrated that combination treatments with natural products and tamoxifen can improve the sensitivity and cytotoxicity of oestrogen-positive breast cancer cells in response to tamoxifen. Celastrol, a triterpene from traditional Chinese medicine, has been proven to exert significant anticancer effects on various cancers. Our study is aimed at exploring the interactive antitumour effects of celastrol combined with tamoxifen and the potential underlying anticancer mechanisms in MCF-7 cells. The results from MTT assays, isobolographic analyses, and clonogenic cell survival assays revealed that a combination of celastrol and tamoxifen exerted synergistic cytotoxic effects in MCF-7 cells. The results from Annexin V/PI staining and flow cytometry analysis suggested that celastrol enhanced tamoxifen-mediated apoptosis. In addition, exposure to a combination of celastrol and tamoxifen inhibited cell proliferation by causing G1 phase cell cycle arrest. Moreover, the distribution of LC3 was monitored by immunofluorescence, and the changes in the LC3II and P62 levels detected by western blot analysis suggested that celastrol in combination with tamoxifen triggered autophagy. Furthermore, the decrease in p-Akt and p-mTOR in MCF-7 cells, along with the increase in the autophagy marker proteins LC3II and P62, suggested that the Akt/mTOR pathway might be involved in the triggering of cell autophagy by the combination treatment. However, in an MCF-7-implanted nude mouse model, it was possible to detect significantly decreased tumour volumes and tumour weights and decreased p-Akt and p-mTOR protein expression in the celastrol+tamoxifen group. Therefore, our study provides the first evidence that celastrol combined with tamoxifen exerts synergistic anticancer effects by inducing apoptosis and autophagy in MCF-7 cells. Considering the urgent need for novel therapeutic strategies in anticancer therapy, this combinatorial approach is worthy of further investigation.

Sequential usage of imidazole followed by tamoxifen to enhance the anticancer effect of tamoxifen in estrogen receptor-positive breast cancer cell lines.

e15057 Background: In women, breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death worldwide. Tamoxifen is the most commonly used drug for the endocrine treatment of breast cancer. It reduces the risk of recurrence and death from breast cancer when given to estrogen-receptor-positive breast cancer patients. It has recently been shown that imidazoles, an antifungal drug, possess anticancer potentials, and it can be a novel therapeutic in cancer treatment. However, the effects of combined treatment with imidazole and tamoxifen are unknown in estrogen receptor-positive breast cancer cell lines. Our study aimed to investigate the effects of imidazole and tamoxifen combination in estrogen receptor-positive breast cancer cell lines. Methods: MCF7 cell line, an estrogen receptor-positive breast cancer cell line, was used in this study. Following 24 hours 50 mM imidazole (molecular grade) treatment, 15µM tamoxifen was treated to MCF-7 cells by 72 hours. As control groups, following for 24-hour imidazole alone treated, only medium treated cells for 72 hours were used. MTT assay was performed for the determination of cell viability. Apoptosis was shown using acridine orange/ethidium bromide staining. The cellular morphological alterations were observed on bright-field microscopy using Giemsa staining. Cell migration status was determined using by in vitro scratch assay. Results: MTT assay results showed that tamoxifen alone treatment for 72 hours decreased cell viability by 18 percent (p &lt; 0.001). On the other hand, cell viability is not affected by imidazole alone treatment for 24 hours compared with the control group (p &gt; 0.05). However, it was calculated that 24 hours of imidazole followed by tamoxifen for 72 hours decreased cell viability up to 42 percent (p &lt; 0.001). Tamoxifen alone group, compared with combined treatment with tamoxifen and imidazole, observed an increase of apoptotic cell numbers in combined treatment with tamoxifen and imidazole group, statistically significantly (p &lt; 0.01). It was observed that cellular morphology was affected by combined treatment with tamoxifen and imidazole. Giemsa staining results showed that MCF 7 cells changed their cellular morphology, lost cell-cell contact, differentiated from parental morphology and cellular morphology, and appeared unhealthy. Parallel to these findings, a decrease in cell migration was observed in the combined-treated group compared to the tamoxifen alone group (p &lt; 0.01). Conclusions: Our results showed that sequential usage of imidazole followed by tamoxifen has an enhanced anticancer effect of tamoxifen in estrogen receptor-positive breast cancer cell lines. These results allow us to establish a new hormonal treatment for patients with breast cancer.

Study on the extract of Huangqi and Ezhu for the crosstalk of exosomes mediating tamoxifen resistance on LCC9 cells.

e12517 Background: Estrogen receptor (ER)-positive breast cancer is the most frequent subtype accounting for about 70% of all cases. Tamoxifen (TAM) is still the most effective drug for treating ER+/PR+ breast cancer. However, recurrence and metastasis still occur in 30-50% of patients due to TAM resistance. Furthermore, studies have shown that breast cancer stem cells (BCSCs) play an important role in TAM resistance, and exosomes regulate dynamic changes of BCSCs in tumor microenvironment. Additionally, the extract of Huangqi and Ezhu (EHE) has been shown to inhibit multiple TAM-associated resistance signaling pathways. In the current study, we investigated the effect of EHE to reverse TAM-resistance in LCC9 cells via crosstalk of distinct types of exosomes. Methods: Exosomes were extracted from LCC9 cells by ultracentrifugation and characterized by particle size detection, transmission electron microscopy and western blot analysis. Subsequently, isolated LCC9 exosomes were used to treat bone marrow stem cells (BMSCs) with EHE only, TAM only, EHE and TAM (EHETAM), and no treatment (negative control, NC). After treatment, exosomes of BMSCs were isolated and incubated further with LCC9 cells. CCK-8 assay and flow cytometry analysis were performed, and protein expression in treated LCC9 cells was tested by western blot analysis. Results: Data from CCK-8 assay showed that compared with the NC group, proliferation of LCC9 cells was significantly reduced in the presence of exosomes of BMSCs treated with TAM (82.9%, 77.1% , 75.4%), EHE (73.2 %, 69.5% , 68.2 %) and EHETAM (68.9 %, 52.3%，54.1% ) after 24h, 48h, and 72 h, respectively (p &lt; 0.001). EHE and EHETAM groups have more effective inhibition on cell proliferation than TAM only group on the different time separately(p &lt; 0.001).Flow cytometry analysis demonstrated that compared with the NC group(6.1%), increased apoptosis was observed for groups of TAM (8.1%), EHE (12.5%) and EHETAM (12.2%) (p &lt; 0.001). Compared with TAM only group, EHE and EHETAM groups also have significantly higher cell death rate (p &lt; 0.001). Lower CD44 and HER2 expression and higher ERα expression were observed in EHE, TAM, and EHETAM than those of NC group by western blot analysis of treated LCC9 cells. Conclusions: EHE treatment can reverse TAM-resistance by interfering with the crosstalk between BMSCs and breast cancer cells exosomes to induce more active apoptosis and reduce TAM-resistant CD44+ cancer stem cells.

Thymoquinone Increased Expression of CD4CD25Treg in Sprague-Dawley Rats Induced Dimethylbenzanthracene

BACKGROUND: The carcinogen dimethylbenzanthracene (DMBA) is immunotoxic. Thymoquinone, meanwhile, is known to have antioxidant and anti-inflammatory effects. AIM: This study aims to determine the effect of thymoquinone and tamoxifen on the CD4CD25Treg count in Sprague-Dawley (SD) rats induced by DMBA. METHODS: The 50 SD rats were divided into five groups. Group I (normal control) was given standard drinking and food. Group II was given thymoquinone, Group III was given tamoxifen, Group IV was given DMBA, and Group V was given solvent control. Thymoquinone, tamoxifen, and solvent control administration started 2 weeks before DMBA administration and continued during DMBA induction. In the 3rd week, except for the normal group, all groups were created to be induced with 10 × 20 mg/kg body weight of DMBA for 5 weeks. In the 21st week, surgery and data collection were performed. The hematology profile and CD4CD25Treg number were carried out employing a flow cytometer. The difference in the average number of CD4CD25Treg and blood cells between groups was analyzed with one-way analysis of variance RESULTS: The results revealed that DMBA induction reduced the number of erythrocytes, HB levels, platelet counts, and leukocyte counts (p &lt; 0.05). The administration of thymoquinone and tamoxifen reduced the hematopoiesis effect of DMBA. The thymoquinone and tamoxifen group had a higher number of CD4CD25Treg and leukocytes than the DMBA group (p &lt; 0.05). CONCLUSION: There was no difference in the average CD4CD25Treg, leukocyte count, lymphocyte count, and monocyte count between the thymoquinone and the tamoxifen groups (p &gt; 0.05).

Randomized Controlled Trial of Breast Nodule Lysis Versus Tamoxifen for the Treatment of Mammary Gland Hyperplasia

To study the efficacy of breast nodule lysis (BNL) for the treatment of mammary gland hyperplasia (MGH). A total of 304 patients with MGH and breast pain were randomly divided into a BNL group and an oral tamoxifen (OT) group. In the BNL group (n = 156), patients were treated with BNL technique once a day for 7 consecutive days. BNL is a novel technique developed by our department, by which breast nodules can be released and breast duct can be cleared via external force and manipulation. In the OT group (n = 148), patients took oral tamoxifen 10 mg once a day for 15 consecutive days beginning 5 days after termination of the menstrual period for 3 menstrual cycles. The McGill Pain Questionnaire (MPQ) score, number and size of breast nodules pre- and post-treatment, efficacy, time to response, total treatment expenses, recurrence rate, and side effects were compared across groups. The MPQ score was significantly better in the BNL than the OT on day 7, and the total effective rate (86.54%) was significantly higher in the BNL than the OT (43.92%) on day 15. The number and size of breast nodules were decreased in the BNL compared with the OT 15 days, 3 months, and 6 months after treatment. The total treatment expenses were higher in the BNL than the OT. The recurrence rate within 6 months was lower in the BNL than the OT. There was no difference in side effects (nausea, vomiting, diarrhea, or dizziness) across groups. BNL can effectively alleviate pain and reduce the number and size of nodules with quick effect and a low recurrence rate, making it an enticing treatment for MGH.

Abstract PD11-08: Low dose endoxifen represses mouse mammary tumorigenesis: A preclinical study of monotherapy and combination with ulipristal acetate

Abstract Background: Endoxifen (ENX), a major active metabolite of the selective estrogen receptor (ER) modulator tamoxifen (TAM), has been shown to inhibit the growth of ER+ cancer. However, it has not been evaluated for prevention of mammary cancer. We report here the cancer prevention efficacy of ENX as monotherapy and in combination with ulipristal acetate (UPA), a selective progesterone receptor (PR) modulator. We compare these to TAM using the SV40 C3 T-antigen (C3-TAg) mouse, a well-documented mammary cancer prevention model. Methods: C3-TAg female virgin mice aged 7-8 weeks were randomized to no-treatment control or to drug treatment groups (TAM, ENX, UPA and ENX+UPA). Drug pellets were subcutaneously implanted on backside of mice. The doses of drug pellet were 12.5mg/30d for TAM, 9mg/90d for ENX, 10mg/30d for UPA, and combination of ENX (9mg/90d) + UPA (10mg/30d). The dose of ENX was equivalent to the exposure resulting from 20 mg/day, the lowest dose used in a recent Phase I human trial. Pellets were replaced every 30 days or 90 days. Mammary tumor formation was monitored twice weekly by palpation. Tumor latency, multiplicity, and tumor volume were recorded; animals are euthanized at 23 weeks of age, or earlier if tumors reach &amp;gt; 1 cm2. Tumors and mammary glands were formalin fixed and paraffin embedded for histology evaluation by a rodent pathologist. The primary endpoint was a reduction in tumor incidence in drug treated versus control groups. Secondary endpoints included prolongation of latency, reduction in tumor multiplicity, and tumor burden. Statistical significance between groups was calculated with Wilcoxon log-rank test for % tumor-free survival and Mann Whitney test for tumor multiplicity and burden.Results: All mice in the control group developed tumors by 18 weeks of age. Tumor-free survival % of ENX, UPA, and ENX+UPA treated groups were significantly higher than control animals, with the greatest increase in the ENX group (p=0.02). TAM had no effect on tumor-free survival (p=0.32). Median tumor latencies were similar in three treated groups: ENX (112 days), UPA (114 days), and ENX+UPA (111 days) groups, and were significantly delayed compared to the control or TAM group (100 days in both) (p&amp;lt;0.05). Median tumor multiplicity (invasive adenocarcinoma) per animal was significantly lower in ENX group compared to control group (3 vs. 7, p=0.02). UPA and TAM did not significantly reduce tumor multiplicity (4 for TAM and 6 for UPA). We observed non-significant 32% and 23% reduction in median tumor weight of ENX+UPA group and ENX group, respectively compared to control group. Histology evaluation for ENX+UPA group and pathologic size of invasive carcinoma is ongoing, along with the expression of Ki67, ERα and PR of mammary tumors and mammary gland by immunohistochemistry.Conclusions: TAM showed no significant effect on delaying tumorigenesis, consistent with a previous study. However, low dose of ENX (equivalent to 24 mg/day in human) effectively repressed tumor development and growth than TAM or UPA treatment. Our data suggest that ENX is promising for prevention of ER+ mammary tumorigenesis and warrant a dose optimization study for improving efficacy. Citation Format: Oukseub Lee, Minhua Wang, Maarten C. Bosland, Omid Hosseini, Irene Helenowski, Seema A. Khan. Low dose endoxifen represses mouse mammary tumorigenesis: A preclinical study of monotherapy and combination with ulipristal acetate [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD11-08.