Racial and Ethnic Differences in BRCA1/2 and Multigene Panel Testing Among Young Breast Cancer Patients

Genetic testing for hereditary breast and ovarian cancer (HBOC) is recommended for breast cancer patients diagnosed at age ≤ 50 years. Our objective was to examine racial/ethnic differences in genetic testing frequency and results among diverse breast cancer patients. A retrospective cohort study among women diagnosed with breast cancer at age ≤ 50 years from January 2007 to December 2017 at Columbia University in New York, NY. Among 1503 diverse young breast cancer patients, nearly half (46.2%) completed HBOC genetic testing. Genetic testing completion was associated with younger age, family history of breast cancer, and earlier stage, but not race/ethnicity or health insurance status. Blacks had the highest frequency of pathogenic/likely pathogenic (P/LP) variants (18.6%), and Hispanics and Asians had the most variants of uncertain significance (VUS), 19.0% and 21.9%, respectively. The percentage of women undergoing genetic testing increased over time from 15.3% in 2007 to a peak of 72.8% in 2015. Over the same time period, there was a significant increase in P/LP and VUS results. Due to uncertainty about the clinical implications of P/LP variants in moderate penetrance genes and VUSs, our findings underscore the need for targeted genetic counseling education, particularly among young minority breast cancer patients.

Abstract P5-09-01: Racial/ethnic differences in BRCA1/2 and multigene panel testing among young breast cancer patients

Background: Breast cancer (BC) patients diagnosed at age 50 and under are recommended to have germline genetic testing for hereditary BC due to a high likelihood of carrying a pathogenic mutation in a moderate or high penetrance risk gene. Completion of genetic testing among racial/ethnic minorities, particularly multigene panel testing, is understudied. We examined predictors of completion of BRCA1/2 and multigene panel testing among women with early onset BC and assessed racial/ethnic differences in genetic testing completion and results.

Methods: We performed a retrospective cohort study of 1370 BC patients diagnosed at <50 years of age at Columbia University Medical Center (CUMC) from January 2007-December 2016.Data on socio-demographics, clinical factors, and genetic testing completion and results were collected from the medical record. We conducted descriptive statistics and univariate and multivariable logistic regression models.

Results: Our study population had a median age of 44 years (range, 19-50); 44% non-Hispanic white, 24% Hispanic, 13% non-Hispanic black, 10% Asian, 9% other; 61% private insurance, 22% Medicaid, 17% other. Nearly half of the women (N=607; 44.3%) had genetic testing performed. In the multivariable regression model, genetic testing completion was less likely with increasing age at diagnosis (odds ratio [OR]=0.93; 95% confidence interval [CI]=0.91-0.95) and stage 0 or 4 BC compared to stage 1 (OR=0.67; 95% CI=0.46-0.97 and OR=0.35; 95% CI=0.19-0.64, respectively). Completion of genetic testing was more likely with a family history of BC (OR=5.55; 95% CI=3.92-7.87). Genetic testing completion did not vary by race/ethnicity or insurance coverage. Across all racial/ethnic groups, the frequency of pathogenic/likely pathogenic variants identified was 13.0% and 10.5% had at least 1 variant of uncertain significance (VUS). The highest VUS frequency was among Asians (21.2%). The percentage of women undergoing genetic testing increased over time from 18.5% in 2007 and reached a peak of 69.3% in 2015. From 2007 to 2016, the percentage of pathogenic/likely pathogenic variants detected increased from 3.4% to 9.1% and the VUS frequency rose from 3.4% to 13.3% with increasing use of panel testing.

Frequency of pathogenic variants and VUS among women ≤ 50 years diagnosed with BC at CUMC (2007-2016) Pathogenic variantsVUSTotal81 (5.9%)74 (5.4%)BRCA144 (3.2%)10 (0.7%)BRCA221 (1.5%)10 (0.7%)ATM3 (0.2%)9 (0.6%)CHEK23 (0.2%)8 (0.5%)Other variants detected in: APC, BARD1, BRIP1, CDH1, CDKN2A, MEN1, MLH1, MRE11A, MSH2, MSH6, MUTYH, NBN, NF1, PALB2, PHOX2B, PMS2, POLE, PTEN, RAD50, RAD51C, SDHA, STK11, TP53

Conclusions and Relevance: Nearly half of the women with early onset BC had genetic testing. We did not observe disparities in genetic testing by race/ethnicity or insurance coverage. Genetic testing completion, as well as the frequency of pathogenic/likely pathogenic variants and VUS detection, increased over time as panel testing replaced BRCA1/2 testing. Counseling on the likelihood of obtaining uncertain results should be provided to all patients undergoing hereditary BC genetic testing, particularly to racial/ethnic minorities.

Citation Format: Trivedi MS, Jones T, Jiang X, Underhill ML, Bose S, Silverman T, Chung WK, Kukafka R, Crew KD. Racial/ethnic differences in BRCA1/2 and multigene panel testing among young breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-09-01.

Abstract P1-20-02: Incidence of hyperglycemia in non-diabetic patients with early-stage breast cancer treated with chemotherapy

Background: There are shared risk factors between breast cancer (BC) and diabetes mellitus (DM). BC treatments including chemotherapy given in combination with glucocorticoids can induce hyperglycemia and steroid related DM. Patients with DM are at increased risk of developing chemotherapy related toxicities such as chemotherapy induced peripheral neuropathy (CIPN) compared to those without DM. The incidence of hyperglycemia during chemotherapy in non-diabetic patients with early-stage breast cancer is unknown.

Methods: We performed a retrospective analysis of non-diabetic women with stage I-III breast cancer treated with chemotherapy at Columbia University Medical Center from 9/1/2016-8/31/2017 to evaluate hyperglycemia incidence during chemotherapy and up to six months after chemotherapy completion. Eligible patients were identified in the electronic health record (EHR) by ICD9 and 10 codes (ICD9 174.x and ICD10 C50.x) and a record of chemotherapy administration. Non-diabetic patients were defined by chart review as no recorded history of diabetes and no receipt of a diabetes medication in the EHR. Breast cancer stage was determined by chart review. Glucose values were recorded prior to chemotherapy, during chemotherapy, and for six-months after chemotherapy completion. We defined hyperglycemia as a glucose value of ≥200 mg/dl. Median time to hyperglycemia was also calculated.

Results: We identified 82 eligible patients. The majority of patients received dexamethasone during their chemotherapy course (79 patients, 96.3%). The most frequent chemotherapy regimen was doxorubicin/cyclophosphamide and paclitaxel (32 patients, 39.0%). At baseline, 20 patients (24.4%) had a normal body mass index (BMI), 27 patients (32.9%) were overweight, and 31 patients (37.8%) were obese. Hyperglycemia occurred in 8 patients (9.8%) after initiation of chemotherapy. Among patients with hyperglycemia, the maximum blood glucose was between 200-299 mg/dl in seven patients (87.5%), and between 500-599 in one patient (12.5%). The median time to hyperglycemia was 84 days. Among patients who did not experience hyperglycemia, the maximum blood glucose was between 140-159 mg/dl in six patients (8.1%), between 160-179 mg/dl in eight patients (10.8%), and between 180-199 mg/dl in three patients (4.1%). Three patients were diagnosed with DM following chemotherapy completion.

Conclusion: Hyperglycemia occurred in almost 10% of non-diabetic patients who received chemotherapy for early-stage breast cancer. Additionally, over 30% of patients had a blood glucose of 140 mg/dl or higher after chemotherapy initiation. The impact of hyperglycemia on the development of chemotherapy related toxicities in this group is unknown. Future research is needed to identify effective interventions for glucose control during chemotherapy, and to determine if glucose control during treatment can reduce the risk of chemotherapy related toxicities, specifically CIPN.

Citation Format: Accordino MK, Lin A, Wright JD, Trivedi MS, Kalinsky K, Crew KD, Hershman DL. Incidence of hyperglycemia in non-diabetic patients with early-stage breast cancer treated with chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-20-02.

Abstract P6-18-35: A phase 1 study of erlotinib and metformin in advanced triple negative breast cancer

Background: The epidermal growth factor receptor (EGFR) is frequently overexpressed in triple negative breast cancer (TNBC). However, EGFR inhibitors have not shown efficacy as monotherapy in TNBC. One strategy for overcoming resistance to EGFR inhibition is concomitant inhibition of downstream signaling. Metformin is a LKB1-dependent AMPK activator that inhibits both MAPK and AKT signaling. The combination of the EGFR inhibitor erlotinib and metformin synergistically induces apoptosis in TNBC cell lines and decreases tumor burden in PTEN-null EGFR-amplified mouse xenograft models. We evaluated the combination of erlotinib and metformin in a phase 1 study of patients with advanced TNBC.

Methods: Patients with advanced TNBC who had received at least one prior line of therapy for metastatic disease were eligible. Erlotinib dose was fixed at 150mg daily. Metformin dose escalation was planned according to a 3+3 design, beginning at 850mg BID and escalating to 850mg TID. One de-escalation to 500mg BID was allowed. Dose-limiting toxicities (DLT) were assessed during the first five weeks of therapy. The primary objectives were to determine the maximum tolerated dose (MTD) of metformin with fixed dose erlotinib and to determine the potential for clinical benefit. Secondary endpoints were response rate, stable disease rate, and progression free survival. Pre- and on-treatment skin biopsies were collected to determine the effect of the study drugs on their respective cell signaling targets, particularly EGFR, AMPK, and mTOR.

Results: Between March 2013 and May 2015, nine patients were screened and eight were enrolled. Median age was 48 years (range 37-79). Median number of prior therapies for metastatic disease was 2.5 (range 1-6). No DLT events were reported in either of the dose escalation cohorts during the DLT assessment period. AEs occurring in three or more patients and all grade III AEs are reported in Table 1. Grade III diarrhea despite maximum supportive care required dose reduction of metformin from 850mg TID to 850mg BID in one patient. Grade III rash led to study withdrawal in one patient. No grade IV AEs were reported. Per RECIST v1.1, the best observed response was stable disease in two patients (25%). Median time on study was 2.0 months (range 1.2-3.0). Skin biopsy marker assessment is ongoing and will be reported.

Conclusion: The combination of erlotinib and metformin was generally well tolerated in a population of pre-treated metastatic TNBC patients. No unexpected toxicities occurred. While no responses were achieved, stable disease was observed in patients who received this non-chemotherapy combination.

Adverse EventsEventMetformin 850mg BID n=3Metformin 850mg TID n=5All patients n=8 Number of patients (percent) All gradesGrade IIIAll gradesGrade IIIAll gradesGrade IIIRash3 (100)1 (33.3)5 (100)08 (100)1 (12.5)Diarrhea3 (100)05 (100)2 (40.0)8 (100)2 (25.0)Weight loss1 (33.3)05 (100)06 (75.0)0Dry skin1 (33.3)05 (100)06 (75.0)0Nausea2 (66.7)03 (60.0)05 (62.5)0Vomiting1 (33.3)03 (60.0)04 (50.0)0Dry mouth1 (33.3)03 (60.0)04 (50.0)0Dysgeusia1 (33.3)02 (40.0)03 (37.5)0Increased creatinine2 (66.7)01 (20.0)03 (37.5)0Fatigue1 (33.3)02 (40.0)03 (37.5)0Anorexia1 (33.3)02 (40.0)03 (37.5)0Hyponatremia1 (33.3)1 (33.3)001 (12.5)1 (12.5)

Citation Format: Fenn KM, Maurer MA, Lee SM, Crew KD, Trivedi MS, Accordino MK, Hershman DL, Kalinsky K. A phase 1 study of erlotinib and metformin in advanced triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-35.

Abstract OT2-09-01: Pilot study of denosumab in BRCA1/2 mutation carriers scheduling for risk-reducing salpingo-oophorectomy

Background: Denosumab is a monoclonal antibody that inhibits RANKL and is approved for the prevention of fractures in patients with osteoporosis or bone metastases. The RANKL signaling pathway is also involved in BRCA1-associated mammary tumorigenesis via a progesterone-induced paracrine effect of RANKL on luminal progenitor cells. Pre-clinical studies have demonstrated that RANKL inhibition resulted in reduced proliferation of mammary tumors. Early findings from an ongoing pre-surgical study demonstrated that denosumab treatment resulted in decreased Ki67 proliferation index in benign breast tissue. Based on these data, denosumab is being pursued as a potential preventive agent for breast cancer in BRCA1 mutation carriers. While promising, the effect of RANKL inhibition on gynecologic tissues such as the ovaries and fallopian tubes, in which progesterone has a protective effect, is unknown.

Trial design: We will conduct a multicenter, open-label randomized pilot study of presurgical administration of denosumab versus no treatment in premenopausal women with BRCA1/2 mutations undergoing risk-reducing salpingo-oophorectomy (RRSO). A total of 60 women will be randomized 1:1 to Arm 1) 3-4 doses of 120 mg denosumab subcutaneously every 4 weeks or Arm 2) No treatment. Participants will be stratified by 1) BRCA1 versus BRCA2 mutation status and 2) Use of hormonal contraceptives within the past 3 months (yes/no). Assuming a 10% unevaluable rate, we expect to have 54 evaluable participants (27 per arm).

Eligibility criteria: 1) Premenopausal women (defined as < 3 months since last menstrual period OR serum follicle-stimulating hormone (FSH) < 20 mIU/mL), age > 18 years; 2) Documented germline pathogenic mutation or likely pathogenic variant in the BRCA1 or BRCA2 gene; 3) Plan for RRSO with or without hysterectomy; 4) ECOG performance status ≤ 1 (Karnofsky ≥ 70%); 5) Normal organ and marrow function; 6) Negative pregnancy test and use of adequate contraception; 7) Willingness to take supplemental oral calcium and vitamin D3; 8) Dental examination within 6 months of enrollment and no evidence of active dental issues; 9) Ability to understand and willingness to provide informed consent.

Specific aims: Our primary objective is to compare the effect of denosumab to no treatment on Ki67 expression in the fimbrial end of the fallopian tube. Secondary objectives are to assess Ki67 in ovary and endometrium; cleaved caspase-3, RANK/RANKL, ER/PR, CD44, and STAT3/pSTAT3 expression in fallopian tube, ovary, and endometrium; gene expression profiling in the fallopian tube and ovary; serum markers (progesterone, estradiol, C-terminal telopeptide) and denosumab levels; and toxicity.

Statistical methods: The primary endpoint is post-treatment Ki67 expression in the fimbrial end of the fallopian tube in the denosumab arm compared to the no treatment arm. Assuming a standard deviation of 5.0%, we will have 82% power to detect a 4.0% absolute difference (or effect size of 0.8) in Ki67 proliferation index between the denosumab and no treatment groups by applying a 2-sample t-test at a 0.05 significance level.

Target accrual: 60 participants, to be activated in Summer 2018.

Citation Format: Trivedi MS, Samimi G, Wright JD, Holcomb K, Garber JE, Horowitz NS, Arber N, Friedman E, Wenham RM, House M, Parnes H, Lee JJ, Abutaseh S, Vornik LA, Heckman-Stoddard BM, Brown PH, Crew KD. Pilot study of denosumab in BRCA1/2 mutation carriers scheduling for risk-reducing salpingo-oophorectomy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-09-01.

Abstract PD6-10: Association between adherence to cardiovascular medications and cardiovascular events following a diagnosis of early stage breast cancer

Background: Studies show that patients diagnosed with early-stage breast cancer (BC) are more likely to die from cardiovascular disease (CVD) than BC. Adherence to CVD medications, such as statins and antihypertensives, is poor in BC survivors, particularly in the year following diagnosis. The impact of non-adherence to CVD medications on cardiovascular events in BC survivors is unknown.

Methods: Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked dataset, we evaluated patients with non-metastatic BC who were diagnosed between 2006-2014. Prescriptions were identified for the treatment of hypertension, hyperlipidemia and diabetes. The pre-cancer diagnosis study period for adherence was defined as 1 year prior to the diagnosis of cancer. The follow up adherence period was between years 1 and 2 following the diagnosis of cancer, so the BC treatment period was not included. Adherence was defined as a medication possession ratio of 380%. A CVD event was defined as an ischemic event or acute heart failure. Patients with a CVD event prior to diagnosis were excluded. Logistic regression was performed for each non-cancer condition to define factors associated with medication non-adherence. Cox regression was used to calculate the association between CVD medication adherence and time-to-subsequent cardiac events, adjusted for baseline factors. Cox regression was performed separately for each non-cancer condition.

Results: Among 23,080 women with BC in the cohort, 15,576 were adherent to at least one CVD medication prior to diagnosis, and of these, 2732 (17.5%) were non-adherent to at least one medication following treatment. Among the women adherent to medications prior to diagnosis, 19.2% were non-adherent to hypertension medications, 26.2% were non-adherent to cholesterol medications, and 30.6% were non-adherent to diabetes medications following the first year of BC treatment. Factors that were associated with non-adherence to anti-hypertensives included receipt of chemotherapy (OR 1.24, p<0.001), other comorbidities (OR 1.34, p<0.001), higher stage (OR 1.18, p <0.001) and hormone receptor negative tumors (OR 1.15, p<0.001). Similar factors were associated with non-adherence to cholesterol medications, whereas only stage and tumor type were associated with non-adherence to diabetes medications. Non-adherence to hypertension medications compared to adherence following diagnosis was associated with an increased risk of having a CVD event (HR 1.33, 95% CI 1.18-1.51, p<0.001; 5-year cumulative incidence of 32% vs 26%, respectively, p<0.001). Similar results were seen for adherence to cholesterol medications (HR 1.21, 95% CI 1.05-1.40, p=0.009) and diabetes medications (HR 1.31, 95% CI 1.09-1.56, p=0.003).

Conclusions:In summary, we found that a large proportion of women who were previously adherent to their medications to prevent CVD events prior to their breast cancer diagnosis were non-adherent following treatment. Of concern, non-adherence to any of these classes of medications resulted in an increased risk of having a cardiovascular event. Improving outcomes and reducing morbidity following a breast cancer diagnosis also requires focused attention on non-breast cancer conditions.

Citation Format: Hershman DL, Accordino M, Shen S, Buono D, Crew KD, Kalinsky K, Trivedi MS, Unger JM, Wright JD. Association between adherence to cardiovascular medications and cardiovascular events following a diagnosis of early stage breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-10.

Identification of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-associated DNA methylation patterns

BACKGROUND

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex condition involving multiple organ systems and characterized by persistent/relapsing debilitating fatigue, immune dysfunction, neurological problems, and other symptoms not curable for at least 6 months. Disruption of DNA methylation patterns has been tied to various immune and neurological diseases; however, its status in ME/CFS remains uncertain. Our study aimed at identifying changes in the DNA methylation patterns that associate with ME/CFS.

METHODS

We extracted genomic DNA from peripheral blood mononuclear cells from 13 ME/CFS study subjects and 12 healthy controls and measured global DNA methylation by ELISA-like method and site-specific methylation status using Illumina MethylationEPIC microarrays. Pyrosequencing validation included 33 ME/CFS cases and 31 controls from two geographically distant cohorts.

RESULTS

Global DNA methylation levels of ME/CFS cases were similar to those of controls. However, microarray-based approach allowed detection of 17,296 differentially methylated CpG sites in 6,368 genes across regulatory elements and within coding regions of genes. Analysis of DNA methylation in promoter regions revealed 307 differentially methylated promoters. Ingenuity pathway analysis indicated that genes associated with differentially methylated promoters participated in at least 15 different pathways mostly related to cell signaling with a strong immune component.

CONCLUSIONS

This is the first study that has explored genome-wide epigenetic changes associated with ME/CFS using the advanced Illumina MethylationEPIC microarrays covering about 850,000 CpG sites in two geographically distant cohorts of ME/CFS cases and matched controls. Our results are aligned with previous studies that indicate a dysregulation of the immune system in ME/CFS. They also suggest a potential role of epigenetic de-regulation in the pathobiology of ME/CFS. We propose screening of larger cohorts of ME/CFS cases to determine the external validity of these epigenetic changes in order to implement them as possible diagnostic markers in clinical setting.

Abstract P6-12-17: Identifying risk factors and effect modifiers of trastuzumab-induced cardiotoxicity among multi-ethnic women with early-stage HER2-positive breast cancer

Introduction: Trastuzumab-based adjuvant therapy is the current standard of care for early-stage HER2-positive breast cancer. However, trastuzumab has also been associated with an increased risk of cardiotoxicity, especially when given following an anthracycline. Trastuzumab-induced cardiotoxicity (TIC) can present as asymptomatic left ventricular ejection fraction (LVEF) decline or symptomatic heart failure. Our objective was to identify predictors of TIC among multi-ethnic patients with early-stage HER2-positive breast cancer. Unlike prior observational studies, our study included a high representation of racial/ethnic minorities, who are at increased risk of cardiovascular disease (CVD) compared to non-Hispanic whites.

Methods: We conducted a retrospective cohort study in patients with stage I-III HER2-positive breast cancer, diagnosed from 2007 to 2015 at Columbia University Medical Center (CUMC) in New York, NY, who had received adjuvant trastuzumab therapy. Participants had at least two serial echocardiograms or MUGA scans to assess TIC, which was defined as at least a 10% decrease in LVEF from baseline or LVEF <50%. LVEF recovery was defined as at least a 10% increase in LVEF or LVEF >50%. We conducted descriptive statistics and univariate and multivariable logistic regression to estimate the associations between socio-demographic factors, breast tumor and treatment characteristics, and CVD risk factors (including smoking status, body mass index [BMI], hypertension, diabetes, hyperlipidemia, coronary artery disease) and TIC. Interactions between race/ethnicity and CVD risk factors were assessed using a logistic regression model.

Results: In our study population (N=279), the mean age was 52.7 years (standard deviation, 12.1) with 36.6% non-Hispanic white, 18.3% non-Hispanic black, 34.8% Hispanic, and 10.4% Asian patients. There were no differences by race/ethnicity in tumor and treatment characteristics (over half had prior anthracyclines), but racial/ethnic minorities had higher BMI and were more likely to have hypertension compared to non-Hispanic whites. About a third of patients developed TIC and 14.7% had an LVEF decline to <50%, of which 15 (16.1%) experienced LVEF recovery. In multivariable analysis, prior anthracycline use and hypertension were significantly associated with increased odds of developing TIC (odds ratio [OR]: 2.25, 95% confidence interval [CI]: 1.25, 4.06; OR: 2.13, 95% CI: 1.15, 3.93, respectively). There was a significant interaction (p=0.027) between race/ethnicity and hypertension on odds of developing TIC with hypertensive non-Hispanic white patients experiencing 6.05 (95% CI: 2.19, 16.75) times the odds of developing TIC compared to non-hypertensive non-Hispanic whites.

Discussion: We observed a higher incidence of TIC and lower incidence of LVEF recovery compared to previous clinical trials. Given patient selection for clinical trials, our results may be more representative of clinical practice settings. We found a particularly high risk among non-Hispanic white patients with hypertension. Patients with hypertension may require closer blood pressure monitoring and treatment with anti-hypertensives in order to reduce risk of developing cardiotoxicity.

Citation Format: Yuan A, Topkara V, Hershman DL, Kalinsky K, Accordino MK, Trivedi MS, Yu A, Genkinger JM, Crew KD. Identifying risk factors and effect modifiers of trastuzumab-induced cardiotoxicity among multi-ethnic women with early-stage HER2-positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-17.

Abstract P4-06-19: Understanding factors associated with uptake of BRCA genetic testing among Orthodox Jewish women using a mixed-methods approach

Background: The prevalence of BRCA1/2 mutations among Ashkenazi Jews is 1 in 40. Compared to family history-based BRCA testing, population-based testing has been shown to detect more mutation carriers in this population. Orthodox Jews (OJ) are the largest and fastest-growing Jewish population in NY and represent a spectrum of observance including Modern Orthodox, Yeshivish, and Chassidic. This understudied population has unique social, cultural, and religious factors that may influence BRCA genetic testing. We examined factors influencing BRCA genetic testing decision-making and uptake among OJ women.

Methods: Using a mixed-methods approach, we conducted a cross-sectional online survey and 4 focus groups among OJ women in 5 communities in the NY/NJ area. The online survey included items on demographics, breast cancer risk factors, and validated measures of genetic testing intention/knowledge, breast cancer worry/risk perception, stigma, and religious/cultural factors affecting medical decision-making. Descriptive statistics and bivariate and multivariable logistic regression models were conducted. We conducted 4 focus groups with purposive sampling of women who responded to the survey. The qualitative analysis of the semi-structured focus group discussions further explored factors affecting BRCA genetic testing uptake.

Results: Among 321 evaluable survey participants, median age was 47 years (range, 25-82); 55.8% were Modern Orthodox, 30.5% Yeshivish, and 2.8% Chassidic; 84% were married; 6.2% and 0.6% had a history of breast and ovarian cancer, respectively. Although 57.6% had a masters or doctoral degree, only 37.7% had adequate genetic testing knowledge. Nearly 20% of the surveyed women had undergone BRCA genetic testing. After adjusting for known confounders, women who met family history criteria for BRCA genetic testing were nearly 10 times more likely to undergo genetic testing. Modern Orthodox compared to non-Modern Orthodox women and married compared to unmarried women were more likely to undergo genetic testing (odds ratio [OR]=2.31, 95% confidence interval [CI]=1.03-5.17; OR=3.49, 95% CI=1.03-11.80, respectively). Compared to Modern Orthodox women, non-Modern Orthodox women were more likely to consult with a rabbi or religious figure when considering genetic testing and other medical decisions. The focus group participants (N=31) confirmed the importance of rabbinic consultation in medical decision-making. Although stigma was not associated with genetic testing uptake in our survey data, it emerged as a prominent factor in decision-making among focus group participants due to its potential impact on marriageability and family.

Conclusions: We found that non-Modern Orthodox and unmarried women are less likely to seek BRCA genetic testing. Among non-Modern Orthodox women, rabbinic consultation was an important factor in genetic testing decision-making. By understanding the religious and cultural issues regarding genetic testing in the OJ community and by engaging faith-based leaders, we can develop culturally sensitive interventions designed to enhance knowledge and informed choice about BRCA genetic testing, which may facilitate the implementation of population-based genetic screening among Ashkenazi Jews.

Citation Format: Trivedi MS, Colbeth H, Yi H, Vanegas A, Starck R, Chung WK, Appelbaum PS, Kukafka R, Schechter I, Crew KD. Understanding factors associated with uptake of BRCA genetic testing among Orthodox Jewish women using a mixed-methods approach [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-06-19.

Short-term sleep deprivation leads to decreased systemic redox metabolites and altered epigenetic status

Sleep is critical for repair as well as the rejuvenation processes in the body and many of these functions are regulated via underlying cellular metabolic homeostasis. Changes in sleep pattern are reported to alter such metabolic function resulting in altered disease susceptibility or behavior. Here, we measured the extent to which overnight total sleep deprivation (SD) in young adult humans can influence systemic (plasma-derived) redox-metabolism including the major antioxidant, glutathione as well as DNA methylation levels. Nineteen participants (n = 19, μ age = 21, SD = 3.09) underwent morning testing before and after overnight total SD. Biochemical measures before and after SD revealed that glutathione, ATP, cysteine, and homocysteine levels were significantly reduced following one night of sleep deprivation (all p’s < 0.01). Parallel to the well-recognized fact that sleep deprivation (maintaining wakefulness) uses up metabolic reserves, we observed that morning cortisol levels were blunted after sleep deprivation. There were no significant correlations between self-reported or actigraphy-measured sleep and the biochemical measurements, strongly indicating that prior sleep behavior did not have any direct influence on the biochemical measures taken at baseline or after sleep deprivation. Results from the current investigation supports the previous literature implicating the induction of oxidative stress and ATP depletion with sleep deprivation. Furthermore, such altered antioxidant status can also induce downstream epigenetic changes. Although we did not measure the specific genes that were altered under the influence of such sleep deprivation, such epigenetic changes could potentially contribute towards disease predisposition.

Abstract P2-07-01: Chemoprevention uptake among women with atypical hyperplasia, lobular and ductal carcinoma in situ

Introduction: Chemoprevention with anti-estrogens can reduce breast cancer risk among high-risk women. However, uptake is estimated to be lower than 15% among women offered anti-estrogens. Women with atypical hyperplasia (AH), lobular carcinoma in situ (LCIS), and ductal carcinoma in situ (DCIS) are at an increased risk of developing invasive breast cancer and often derive more benefit from anti-estrogens compared to other high-risk populations. We sought to determine which factors are associated with chemoprevention uptake in a population of women with AH, LCIS, and DCIS.

Methods: We conducted a retrospective cohort study at an urban academic center in New York, NY of women diagnosed with AH/LCIS/DCIS between 2007 and 2015 without a history of invasive breast cancer (n=1719). Demographic and clinical information, including type of anti-estrogen and medical oncology referral, were collected from the electronic health record. Breast disease in each patient was classified according to the most advanced lesion (DCIS&gt;LCIS&gt;AH). A subset of women with AH/LCIS/DCIS scheduled for an initial consultation with a medical oncologist (n=73) completed questionnaires on their breast cancer and chemoprevention knowledge, risk perception, and behavioral intentions. Descriptive statistics were generated and univariate and multivariable log-binomial regression were used to estimate the association between sociodemographic and clinical factors and chemoprevention uptake.

Results: In our sample, mean age was 60 years (SD 12); white/black/Hispanic/Asian/other (%): 45/9/23/6/17; AH/LCIS/DCIS (%): 35/24/41; and 33% were referred to a medical oncologist. A total of 505 (29%) women had initiated an anti-estrogen, including 54% who used tamoxifen, 15% raloxifene, 19% aromatase inhibitors, and 11% who tried multiple anti-estrogens. Older women and Hispanics compared to non-Hispanic whites were more likely to take anti-estrogens. Compared to women with AH, LCIS (RR: 1.43; 95% CI: 1.16-1.76) and DCIS (RR: 1.54; 95% CI: 1.28-1.86) were significantly associated with chemoprevention uptake. Medical oncology referral was the strongest predictor of chemoprevention uptake (RR: 5.79; 95% CI: 4.80-6.98). According to the survey data, many women had heard of anti-estrogens for chemoprevention (75%), but few were knowledgeable about it. The majority of participants were worried about the side effects of chemoprevention (72%) and considered them very serious (57%). Satisfaction was high among those who reported making a decision to take chemoprevention, however, only 50% of survey participants thought the benefits of anti-estrogens were worth the risks.

Conclusions: At our center, women with AH, LCIS, and DCIS have higher rates of chemoprevention uptake compared to the reported literature. Despite the potential for younger women to see a greater lifelong benefit from chemoprevention, our results indicate this population may be less likely to use anti-estrogens. Misperceptions about personal breast cancer risk and chemoprevention adverse effects may be barriers to uptake. Improving patient-provider communication about breast cancer risk and the risks and benefits of chemoprevention may facilitate informed-decision making about anti-estrogen therapy.

Citation Format: Coe AM, Trivedi MS, Vanegas A, Kukafka R, Crew KD. Chemoprevention uptake among women with atypical hyperplasia, lobular and ductal carcinoma in situ [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-07-01.

Abstract P5-10-01: Adherence to healthy lifestyle behaviors in a predominantly Hispanic population of women undergoing screening mammography

This abstract was not presented at the symposium.

Abstract P2-09-23: Factors associated with BRCA genetic testing intention and uptake among Orthodox Jewish women

Background: Ashkenazi Jews have a 1 in 40 prevalence of carrying a BRCA1/2 mutation, mainly due to 3 founder mutations. Prior literature suggests that population-based genetic testing among Ashkenazi Jews is cost-effective and may detect over 50% more mutation carriers than family history-based screening. Orthodox Jewish women are an understudied population with unique social, cultural, and religious factors that may influence BRCA genetic testing. The aim of our study was to examine factors associated with BRCA genetic testing intention/uptake among the Orthodox Jewish community.

Methods: A one-time online survey was distributed to Orthodox Jewish women by 3 shuls from Washington Heights, NY (53% response rate) and through additional referrals. The questionnaire obtained information regarding demographics, breast cancer risk factors, genetic testing knowledge, decision self-efficacy, perceived breast cancer risk, breast cancer worry, and religious and cultural factors affecting medical decision-making. The Tyrer-Cuzick model was used to calculate lifetime breast cancer risk and accurate risk perception was defined as within +/-10% of actual lifetime risk. Descriptive statistics and multivariable logistic regression models were used to identify independent predictors of genetic testing intention/uptake.

Results: Among 342 evaluable participants, median age was 26 years (range, 19-77); 92% were Ashkenazi and 8% Ashkenazi/Sephardi; 98% had a college education, including 47% with post-graduate degrees. Despite being highly educated, only 54% of women had adequate genetic testing knowledge. Median lifetime breast cancer risk was 16% (range, 2.3-60.9) and only 44% had accurate breast cancer risk perceptions. Although 48% had a family history of breast cancer and 16% had a relative that tested positive for BRCA1/2 mutation, only 5% had undergone BRCA testing while 48% had the intention of undergoing genetic testing. Higher lifetime breast cancer risk, high decision self-efficacy regarding genetic testing, overestimation of breast cancer risk, and increased breast cancer worry were associated with genetic testing intention/uptake. The most important factors in the decision to have BRCA testing were to help prevent dying of cancer (55%), to help prevent getting cancer (54%), and effect on children (40%).

Multivariable analysis of factors associated with BRCA genetic testing intention/uptake OR95% CIp-valueDecision Self-Efficacy (range, 0 [not confident] - 4 [very confident])1.41.02-1.980.038Actual Lifetime Breast Cancer Risk (range, 0 - 100%)1.11.03-1.100.0005Accuracy in Breast Cancer Risk Perception   Accurate (referent)1.0--Underestimate1.20.50-2.850.691Overestimate2.61.45-4.610.001Breast Cancer Worry (range, 1 [none] - 7 [worry all of the time])1.51.18-1.980.001

Conclusions: By understanding the religious and cultural issues regarding genetic testing in the Orthodox Jewish community, we can develop targeted interventions designed to enhance decision self-efficacy and improve accuracy of breast cancer risk perceptions to decrease unnecessary worry. This may in turn increase informed decision-making about BRCA genetic testing and implementation of cancer prevention strategies among Ashkenazi Jews.

Citation Format: Trivedi MS, Tang EY, Kukufka R, Chung WK, David R, Respler L, Leifer S, Schechter I, Crew KD. Factors associated with BRCA genetic testing intention and uptake among Orthodox Jewish women. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-23.

Decreased Brain Levels of Vitamin B12 in Aging, Autism and Schizophrenia

Many studies indicate a crucial role for the vitamin B₁₂ and folate-dependent enzyme methionine synthase (MS) in brain development and function, but vitamin B₁₂ status in the brain across the lifespan has not been previously investigated. Vitamin B₁₂ (cobalamin, Cbl) exists in multiple forms, including methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), serving as cofactors for MS and methylmalonylCoA mutase, respectively. We measured levels of five Cbl species in postmortem human frontal cortex of 43 control subjects, from 19 weeks of fetal development through 80 years of age, and 12 autistic and 9 schizophrenic subjects. Total Cbl was significantly lower in older control subjects (> 60 yrs of age), primarily reflecting a >10-fold age-dependent decline in the level of MeCbl. Levels of inactive cyanocobalamin (CNCbl) were remarkably higher in fetal brain samples. In both autistic and schizophrenic subjects MeCbl and AdoCbl levels were more than 3-fold lower than age-matched controls. In autistic subjects lower MeCbl was associated with decreased MS activity and elevated levels of its substrate homocysteine (HCY). Low levels of the antioxidant glutathione (GSH) have been linked to both autism and schizophrenia, and both total Cbl and MeCbl levels were decreased in glutamate-cysteine ligase modulatory subunit knockout (GCLM-KO) mice, which exhibit low GSH levels. Thus our findings reveal a previously unrecognized decrease in brain vitamin B₁₂ status across the lifespan that may reflect an adaptation to increasing antioxidant demand, while accelerated deficits due to GSH deficiency may contribute to neurodevelopmental and neuropsychiatric disorders.

Epigenetic effects of casein-derived opioid peptides in SH-SY5Y human neuroblastoma cells

Background

Casein-free, gluten-free diets have been reported to mitigate some of the inflammatory gastrointestinal and behavioral traits associated with autism, but the mechanism for this palliative effect has not been elucidated. We recently showed that the opioid peptide beta-casomorphin-7, derived from bovine (bBCM7) milk, decreases cysteine uptake, lowers levels of the antioxidant glutathione (GSH) and decreases the methyl donor S-adenosylmethionine (SAM) in both Caco-2 human GI epithelial cells and SH-SY5Y human neuroblastoma cells. While human breast milk can also release a similar peptide (hBCM-7), the bBCM7 and hBCM-7 vary greatly in potency; as the bBCM-7 is highly potent and similar to morphine in it's effects. Since SAM is required for DNA methylation, we wanted to further investigate the epigenetic effects of these food-derived opioid peptides. In the current study the main objective was to characterize functional pathways and key genes responding to DNA methylation effects of food-derived opioid peptides.

Methods

SH-SY5Y neuroblastoma cells were treated with 1 μM hBCM7 and bBCM7 and RNA and DNA were isolated after 4 h with or without treatment. Transcriptional changes were assessed using a microarray approach and CpG methylation status was analyzed at 450,000 CpG sites. Functional implications from both endpoints were evaluated via Ingenuity Pathway Analysis 4.0 and KEGG pathway analysis was performed to identify biological interactions between transcripts that were significantly altered at DNA methylation or transcriptional levels (p < 0.05, FDR <0.1).

Results

Here we show that hBCM7 and bBCM7, as well as morphine, cause epigenetic changes affecting gene pathways related to gastrointestinal disease and inflammation. These epigenetic consequences exhibited the same potency order as opiate inhibition of cysteine uptake insofar as hBCM7 was less potent than bBCM7, which was less potent than morphine.

Conclusion

Our findings indicate that epigenetic effects of milk-derived opiate peptides may contribute to GI dysfunction and inflammation in sensitive individuals. While the current study was performed using SH-SY5Y neuronal cellular models, similar actions on other cells types might combine to cause symptoms of intolerance. These actions may provide a potential contributing mechanism for the beneficial effects of a casein-free diet in alleviating gastrointestinal symptoms in neurological conditions including autism and other conditions. Lastly, our study also contributes to the evolving awareness of a “gut-brain connection”.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-015-0050-1) contains supplementary material, which is available to authorized users.

Multifunctional Polymeric Micelles Co-loaded with Anti-Survivin siRNA and Paclitaxel Overcome Drug Resistance in an Animal Model of Ovarian Cancer

Ovarian cancer is a dreadful disease estimated to be the second most common gynecologic malignancy worldwide. Its current therapy, based on cytoreductive surgery followed by the combination of platinum and taxanes, is frequently complicated by the onset of multidrug resistance (MDR). The discovery that survivin, a small antiapoptotic protein, is involved in chemoresistance provided a new prospect to overcome MDR in cancer, because siRNA could be used to inhibit the expression of survivin in cancer cells. With this in mind, we have developed self-assembly polymeric micelles (PM) able to efficiently co-load an anti-survivin siRNA and a chemotherapeutic agent, such as paclitaxel (PXL; survivin siRNA/PXL PM). Previously, we have successfully demonstrated that the downregulation of survivin by using siRNA-containing PM strongly sensitizes different cancer cells to paclitaxel. Here, we have evaluated the applicability of the developed multifunctional PM in vivo. Changes in survivin expression, therapeutic efficacy, and biologic effects of the nanopreparation were investigated in an animal model of paclitaxel-resistant ovarian cancer. The results obtained in mice xenografed with SKOV3-tr revealed a significant downregulation of survivin expression in tumor tissues together with a potent anticancer activity of survivin siRNA/PXL PM, while the tumors remained unaffected with the same quantity of free paclitaxel. These promising results introduce a novel type of nontoxic and easy-to-obtain nanodevice for the combined therapy of siRNA and anticancer agents in the treatment of chemoresistant tumors.

Redox-based epigenetic status in drug addiction: a potential contributor to gene priming and a mechanistic rationale for metabolic intervention

Alcohol and other drugs of abuse, including psychostimulants and opioids, can induce epigenetic changes: a contributing factor for drug addiction, tolerance, and associated withdrawal symptoms. DNA methylation is a major epigenetic mechanism and it is one of more than 200 methylation reactions supported by methyl donor S-adenosylmethionine (SAM). Levels of SAM are controlled by cellular redox status via the folate and vitamin B12-dependent enzyme methionine synthase (MS). For example, under oxidative conditions MS is inhibited, diverting its substrate homocysteine (HCY) to the trans sulfuration pathway. Alcohol, dopamine, and morphine, can alter intracellular levels of glutathione (GSH)-based cellular redox status, subsequently affecting SAM levels and DNA methylation status. Here, existing evidence is presented in a coherent manner to propose a novel hypothesis implicating the involvement of redox-based epigenetic changes in drug addiction. Further, we discuss how a “gene priming” phenomenon can contribute to the maintenance of redox and methylation status homeostasis under various stimuli including drugs of abuse. Additionally, a new mechanistic rationale for the use of metabolic interventions/redox-replenishers as symptomatic treatment of alcohol and other drug addiction and associated withdrawal symptoms is also provided. Hence, the current review article strengthens the hypothesis that neuronal metabolism has a critical bidirectional coupling with epigenetic changes in drug addiction exemplified by the link between redox-based metabolic changes and resultant epigenetic consequences under the effect of drugs of abuse.

Food-derived opioid peptides inhibit cysteine uptake with redox and epigenetic consequences

Dietary interventions like gluten-free and casein-free diets have been reported to improve intestinal, autoimmune and neurological symptoms in patients with a variety of conditions; however, the underlying mechanism of benefit for such diets remains unclear. Epigenetic programming, including CpG methylation and histone modifications, occurring during early postnatal development can influence the risk of disease in later life, and such programming may be modulated by nutritional factors such as milk and wheat, especially during the transition from a solely milk-based diet to one that includes other forms of nutrition. The hydrolytic digestion of casein (a major milk protein) and gliadin (a wheat-derived protein) releases peptides with opioid activity, and in the present study, we demonstrate that these food-derived proline-rich opioid peptides modulate cysteine uptake in cultured human neuronal and gastrointestinal (GI) epithelial cells via activation of opioid receptors. Decreases in cysteine uptake were associated with changes in the intracellular antioxidant glutathione and the methyl donor S-adenosylmethionine. Bovine and human casein-derived opioid peptides increased genome-wide DNA methylation in the transcription start site region with a potency order similar to their inhibition of cysteine uptake. Altered expression of genes involved in redox and methylation homeostasis was also observed. These results illustrate the potential of milk- and wheat-derived peptides to exert antioxidant and epigenetic changes that may be particularly important during the postnatal transition from placental to GI nutrition. Differences between peptides derived from human and bovine milk may contribute to developmental differences between breastfed and formula-fed infants. Restricted antioxidant capacity, caused by wheat- and milk-derived opioid peptides, may predispose susceptible individuals to inflammation and systemic oxidation, partly explaining the benefits of gluten-free or casein-free diets.

Age-dependent decrease and alternative splicing of methionine synthase mRNA in human cerebral cortex and an accelerated decrease in autism

The folate and vitamin B12-dependent enzyme methionine synthase (MS) is highly sensitive to cellular oxidative status, and lower MS activity increases production of the antioxidant glutathione, while simultaneously decreasing more than 200 methylation reactions, broadly affecting metabolic activity. MS mRNA levels in postmortem human cortex from subjects across the lifespan were measured and a dramatic progressive biphasic decrease of more than 400-fold from 28 weeks of gestation to 84 years was observed. Further analysis revealed alternative splicing of MS mRNA, including deletion of folate-binding domain exons and age-dependent deletion of exons from the cap domain, which protects vitamin B12 (cobalamin) from oxidation. Although three species of MS were evident at the protein level, corresponding to full-length and alternatively spliced mRNA transcripts, decreasing mRNA levels across the lifespan were not associated with significant changes in MS protein or methionine levels. MS mRNA levels were significantly lower in autistic subjects, especially at younger ages, and this decrease was replicated in cultured human neuronal cells by treatment with TNF-α, whose CSF levels are elevated in autism. These novel findings suggest that rather than serving as a housekeeping enzyme, MS has a broad and dynamic role in coordinating metabolism in the brain during development and aging. Factors adversely affecting MS activity, such as oxidative stress, can be a source of risk for neurological disorders across the lifespan via their impact on methylation reactions, including epigenetic regulation of gene expression.

Efficient down-regulation of PKC-α gene expression in A549 lung cancer cells mediated by antisense oligodeoxynucleotides in dendrosomes

The completion of human genome project has increased our knowledge of the molecular mechanisms of many diseases, including cancer, thus providing new opportunities for gene therapy. Antisense oligodeoxynucleotides (AsODN) possess great potential as sequence-specific therapeutic agents, which in contrast to classic treatments provide more efficient and target-specific approach to modulate disease-related genes. To be therapeutically effective, sufficient concentrations of intact AsODN must bypass membrane barriers and access the site of action. In this study, a dendrosome delivery strategy was designed to improve the encapsulation of AsODN in non-cationic liposomes to target PKC-α in lung cancer cells in vitro. Subcellular trafficking of fluorescently labeled AsODN was visualized using confocal microscopy. Uptake and expression of mRNA and target protein after AsODN delivery was measured by flow cytometry, qRT-PCR and Western blot analysis, respectively. Dendrosomes showed favorable physicochemical parameters: high encapsulation efficiency and uptake in serum-containing medium with no apparent cytotoxicity. AsODN encapsulated in dendrosome efficiently and specifically suppress the target gene at both mRNA and protein levels. Additional in vivo studies on the application of dendrosome as a delivery system for nucleic acid molecules may lead to improvement of this technology and facilitate the development of therapeutic antisense techniques.

Role of a redox-based methylation switch in mRNA life cycle (pre- and post-transcriptional maturation) and protein turnover: implications in neurological disorders

Homeostatic synaptic scaling in response to neuronal stimulus or activation, and due to changes in cellular niche, is an important phenomenon for memory consolidation, retrieval, and other similar cognitive functions (Turrigiano and Nelson, 2004). Neurological disorders and cognitive disabilities in autism, Rett syndrome, schizophrenia, dementia, etc., are strongly correlated to alterations in protein expression (both synaptic and cytoplasmic; Cajigas et al., 2010). This correlation suggests that efficient temporal regulation of synaptic protein expression is important for synaptic plasticity. In addition, equilibrium between mRNA processing, protein translation, and protein turnover is a critical sensor/trigger for recording synaptic information, normal cognition, and behavior (Cajigas et al., 2010). Thus a regulatory switch, which controls the lifespan, maturation, and processing of mRNA, might influence cognition and adaptive behavior. Here, we propose a two part novel hypothesis that methylation might act as this suggested coordinating switch to critically regulate mRNA maturation at (1) the pre-transcription level, by regulating precursor-RNA processing into mRNA, via other non-coding RNAs and their influence on splicing phenomenon, and (2) the post-transcription level by modulating the regulatory functions of ribonucleoproteins and RNA binding proteins in mRNA translation, dendritic translocation as well as protein synthesis and synaptic turnover. DNA methylation changes are well recognized and highly correlated to gene expression levels as well as, learning and memory; however, RNA methylation changes are recently characterized and yet their functional implications are not established. This review article provides some insight on the intriguing consequences of changes in methylation levels on mRNA life-cycle. We also suggest that, since methylation is under the control of glutathione anti-oxidant levels (Lertratanangkoon et al., 1997), the redox status of neurons might be the central regulatory switch for methylation-based changes in mRNA processing, protein expression, and turnover. Lastly, we also describe experimental methods and techniques which might help researchers to evaluate the suggested hypothesis.

A brief review on recent developments in animal models of schizophrenia

Number of patients suffering from schizophrenia is increasing daily, subsequently, increasing the need of proper medication to treat the symptoms and eventually improve the patients' condition. However, all the progress for designing or discovering medication comes to a standstill, as the symptomatic treatment can only be done in the patients, but performing clinical trials with all the possible candidate drugs in human beings and patients is unethical. Thus, the need arises for proper animal and non-human primate animal models of the disease, which would not only serve the purpose of understanding the disease in a better physiological setting, but also would allow the scientists to focus on developing a therapeutically effective and potent medication for treating this hazardous disease. This brief review article focuses on a few animal models which are generally used for carrying out studies on schizophrenic symptoms in research labs and industry worldwide. The paper also tries to validate the pre-clinically available models based on certain specified criteria like the predictive constructive and face validity. Thus, the paper gives guidance toward the mechanistic and traditional models of schizophrenia applying some of the newer principles and helps researchers in deciding a particular relevant model for their own purpose.