Vasomotor symptoms and management of women undergoing treatment for breast cancer: literature review with focus on the therapeutic potential of cytoplasmic pollen extract

OBJECTIVE

Effective management of vasomotor symptoms (VMS) in patients undergoing treatment for breast cancer (BC) represents a critical but frequent unmet need. This review summarizes the epidemiology, pathophysiology, and clinical features of VMS in patients with BC and provides a synopsis of the complementary and alternative medicine (CAM) approaches in relieving VMS with a focus on purified cytoplasm of pollen (PCP).

METHODS

The literature on VMS epidemiology, pathophysiology, clinical burden, and CAM treatment in healthy women and patients with BC was reviewed.

RESULTS

VMS are common in patients with BC undergoing hormonal treatment and negatively impact quality of life, leading to treatment discontinuation in up to 25% of patients with detrimental impact on risk of BC recurrence and overall survival. CAM approaches to treat VMS in patients with BC include vitamin E, phytoestrogens, and black cohosh, even if there is a lack of solid evidence to guide clinicians in the choice of treatment. PCP, obtained according to standards of good manufacturing practice, has a definite pharmacological mechanism of action, is devoid of estrogen activity, and has shown clinical efficacy on menopause-associated symptoms with a favorable safety profile and high compliance. As such, it appears to represent a valid management option to improve quality of life in patients with pre- and postmenopausal BC.

CONCLUSIONS

Physicians should actively investigate the presence and impact of VMS in patients receiving therapy for BC. Additional and appropriately sized randomized clinical trials are needed to provide clear evidence on how to best meet the needs of patients with BC suffering from menopause-associated symptoms.

The flavonoid, kaempferol-3-O-apiofuranosyl-7-O-rhamnopyranosyl, as a potential therapeutic agent for breast cancer with a promoting effect on ovarian function

It is widely known that breast cancer cells eventually develop resistance to hormonal drugs and chemotherapies, which often compromise fertility. This study aimed to investigate the effect of the flavonoid, kaempferol-3-O-apiofuranosyl-7-O-rhamnopyranosyl (KARP), on 1) the viability of MCF-7 breast cancer cells and 2) ovarian function in rats. A dose-dependent decrease in MCF-7 cell survival was observed, and the IC50 value was found to be 48 μg/ml. Cells in the control group or those exposed to increasing concentrations of KARP experienced a similar generation of reactive oxygen species and induction of apoptosis. For the rats, estradiol levels correlated negatively to KARP dosages, although a recovery was obtained at administration of 30 mg/kg per day. Noteworthily, when compared against the control, this dosage led to significant increases in mRNA levels for CYP19, CYP17a, CCND2, GDF9, and INSL3 among the treatment groups, and ER1 and ER2 mRNA levels decreased in a dose-dependent manner. KARP shows great promise as an ideal therapy for breast cancer patients since it induced apoptosis and autophagy in cancerous cells without harming fertility in our animal model. Future investigations on humans are necessary to substantiate these findings and determine its efficacy as a general line of treatment.

The association between soy isoflavone intake and menopausal symptoms after breast cancer diagnosis: a prospective longitudinal cohort study on Chinese breast cancer patients

PURPOSE

This study investigated the association between soy isoflavone intake and menopausal symptoms (MPS) among Chinese women with early stage breast cancer in a prospective cohort study.

METHODS

In an on-going prospective cohort study that involved 1462 Chinese women with early stage breast cancer, MPS were assessed at 18, 36 and 60 months after cancer diagnosis using the validated menopausal rating scale (MRS) questionnaire. Daily soy food intake for the previous 12 months was assessed at the same time using a validated food frequency questionnaire. The associations between MPS and soy isoflavone intake were evaluated in multivariable logistic regression analyses.

RESULTS

The prevalence of MPS was almost the same during the first 60 months after cancer diagnosis, which were 64.5%, 65.2%, and 63.9% at 18, 36, and 60 months, respectively. Patients with MPS tended to be younger than those without MPS. The intake of soy isoflavones was not associated with the total score of MRS at 18-month follow-up [highest vs lowest tertile, odds ratio (OR) = 1.00, 95% CI 0.75-1.34]. Similarly, no significant association was noted at 36-month (OR = 1.25, 95% CI 0.92-1.69) and 60-month (OR = 1.21, 95% CI 0.84-1.74) follow-up. With regards to specific domain within MRS, the risk of symptoms presenting in somatic domain was higher among breast cancer patients who were in the highest tertile of soy isoflavone intake at 36 months post-diagnosis (OR = 1.44, 95% CI 1.07-1.94, P-trend = 0.02), compared with the lowest tertile, where a stronger significant association was noted among patients who were younger than 60 years (OR = 1.52, 95% CI 1.05-2.20, P-trend = 0.03) and pre-menopausal (OR = 3.81, 95% CI 1.85-8.11, P-trend < 0.01).

CONCLUSION

The present study provided further evidence that soy isoflavone consumption was not associated with MPS among Chinese breast cancer patients. In fact, patients with higher intake of soy isoflavone have increased risk of experiencing somatic symptoms.

Circ_0001667 promotes breast cancer cell proliferation and survival via Hippo signal pathway by regulating TAZ

Background

Breast cancer is a most common type of cancer in women. Circular RNAs (circRNAs) are involved in cancer development and progression, but their roles and regulatory mechanisms are unclear in breast cancer. Our previous study indicated that has_circ_0001667 (circ_0001667) was up-regulated in breast cancer from the array and might play an oncogenic role, however, the roles of circ_0001667 were not known. This study was aimed to investigate the role and the underlying molecular mechanism of circ_0001667 in breast cancer.

Results

The real-time PCR result showed that circ_0001667 was overexpressed in breast cancer tissues or cell lines compared to the adjacent normal tissues or normal cells. There was a negative relationship between circ_0001667 levels and the life time of breast cancer patients. Meanwhile, the inhibition of circ_0001667 suppressed the proliferation and metastasis of human breast cancer cells. Further bioinformatical analysis indicated that circ_0001667 sponged miR-125a-5p to regulate TAZ expression by Targetscan and miRanda. Dual luciferase reporter assay and western blotting experiments revealed that circ_0001667 negatively regulated miR-125a-5p expression leading to promoting TAZ expression through Hippo signal pathway in breast cancer cells.

Conclusions

This study uncovered that circ_0001667 was a potential breast cancer prognostic marker, as well as a potential therapeutic target to inhibit breast cancer metastasis by circ_0001667/miR-125a-5p/TAZ axis.

A menopause survey of women with benign breast disease history in northwest China

Objectives: The present study aimed to determine the prevalence of menopause syndrome (MPS) and the present treatment status for menopause symptoms in women with benign breast disease history, compared with those without breast problems, and to analyze the affecting factors of medical visits and hormone replacement therapy (HRT) application for menopause symptoms. Methods: A questionnaire survey was conducted by face-to-face interview with a general sample of 8500 Chinese women aged 45-55 years from 162 villages and towns of Gansu province, China. Results: The MPS prevalence in the Benign breast disease history group was 76.60%, and was not statistically different from that of the Control group. Few of the participants had medical visits or had undergone treatment. The Benign breast disease history group was more informed of the treatment options available and more likely to start HRT. Conclusions: Most women with benign breast disease history experienced menopausal symptoms when experiencing reproductive senescence, they had more knowledge about menopause syndrome and more positive to the therapeutic than whom without breast problems.

Effects of phytoestrogens on the activity and growth of primary breast cancer cells ex vivo

AIM

To explore the ex vivo effects of phytoestrogens on primary human breast cancer cells.

METHODS

Breast cancer cells were obtained from patients who underwent primary breast cancer surgery, which were treated with 10^-8  M 17β-estradiol (E₂ ), one of three phytoestrogens (genistein, resveratrol and quercetin, 10^-7  M), and a combination of E₂ and one of the three phytoestrogens for 48 h. These cells were then extracted for viability and apoptosis assay. The proteins involved in the proliferative and apoptotic pathways were evaluated by western blot analysis.

RESULTS

Human breast cancer cell viability was inhibited by all phytoestrogens but induced by E₂ with or without phytoestrogen. Apoptotic cells, as well as the proteins involved in apoptotic pathway and estrogen receptor (ER) β, were significantly increased in the cells treated with phytoestrogen alone. The use of E₂ with or without a phytoestrogen revealed completely opposite results. The proteins involved in the proliferative pathway and ER α expression were all increased in the cultures with E₂ with or without phytoestrogens.

CONCLUSION

In the presence of E₂ , these phytoestrogens lose the effects of suppressing breast cancer cells; contrastingly, induce growth stimulatory effects by inhibiting apoptosis and stimulating proliferation in primary breast cancer cells. Thus, the effects of phytoestrogens on breast cancer should be considered as E₂ still present in breast cancer tissue.

The phytoestrogens daidzein and equol inhibit the drug transporter BCRP/ABCG2 in breast cancer cells: potential chemosensitizing effect

PURPOSE

The soy isoflavone genistein has been described to up-regulate breast cancer resistance protein (BCRP) and, thus, enhance chemoresistance in breast cancer cells. The aim of this work was to assess the effect of long- and short-term incubation with daidzein, the second most abundant soy isoflavone and its metabolite equol on the expression and activity of P-glycoprotein, multidrug resistance-associated proteins 1 and 2 (MRP1 and MRP2) and BCRP in breast cancer cells.

METHODS

MCF-7 and MDA-MB-231 cells were treated with phytoestrogen concentrations within the range achieved in individuals with a high isoflavone intake. Transporter expression was evaluated at protein and mRNA level through western blot and qRT-PCR, respectively. Transporter activity was determined using doxorubicin, mitoxantrone and carboxy-dichlorofluorescein as substrates.

RESULTS

Daidzein (5 µM) up-regulated MRP2- and down-regulated MRP1 protein expressions in MCF-7 and MDA-MB-231 cells, respectively. Both effects were ER-dependent, as determined using the antagonist ICI 182,780. The decrease in MRP1 mRNA in MDA-MB-231 cells indicates a transcriptional mechanism. On the contrary, MRP2 induction in MCF-7 cells takes place post-transcriptionally. Whereas changes in the transporter expression had a minor effect on the transporter activity, acute incubation with daidzein, R-equol and S-equol led to a strong inhibition of BCRP activity and an increase in the IC₅₀ of BCRP substrates.

CONCLUSIONS

In contrast to previous reports for genistein, daidzein and equol do not provoke a major up-regulation of the transporter expression but instead an inhibition of BCRP activity and sensitization to BCRP substrates.