Infertility: A common target of antivaccine misinformation campaigns

Misinformation, disinformation, and conspiracy theories about vaccines are key drivers of vaccine hesitancy. A repeated false claim about COVID-19 vaccines is that the vaccines cause female infertility. Dating back decades, various conspiracy theories have linked vaccination programs with infertility and thus harmed vaccination programs in Africa, Asia, and Central America, particularly against polio and tetanus. In the United States, Europe, and Australia, human papilloma virus (HPV) vaccines have been falsely blamed for infertility and primary ovarian insufficiency (POI). After distribution of COVID-19 vaccines began in December 2020, almost immediately there arose conspiracy theories claiming that these vaccines cause menstrual irregularities, miscarriages, and infertility, promoted by noted antivaccine activists Robert F. Kennedy, Jr. and Andrew Wakefield among others. Here we will explore the history of this antivaccine narrative, how it has been promulgated in the past and repurposed to COVID-19 vaccines, and strategies to counter it.

Abstract 5805: Treatment-associated endocrine symptoms and change in ultrasound tomography measures of breast density after tamoxifen therapy

Background: Tamoxifen therapy has been shown to have greater therapeutic benefit among women whose breast density declines subsequent to treatment than among women whose density does not decline. Although limited data suggests that endocrine symptoms after tamoxifen initiation may be associated with improved breast cancer outcomes, it is unknown whether these symptoms are associated with reductions in breast density. We therefore evaluated endocrine symptoms and change in breast density in a 12-month longitudinal study of women undergoing tamoxifen therapy for clinical indications.

Methods: Cohort members (N=74) were aged 30-74 years in the Ultrasound Study of Tamoxifen at Karmanos Cancer Institute and Henry Ford Health Systems (Detroit, MI). Endocrine symptoms and breast density were both assessed prior to tamoxifen initiation (T0) and at 1-3 months (T1), 4-6 months (T2), and approximately 12 months (T3) post-tamoxifen initiation. Treatment-associated endocrine symptoms included treatment-emergent or increasing vasomotor and/or joint symptoms. Endocrine symptom severity was also assessed with a Likert scale for symptom frequency and categorized as no symptoms (score=0), low/moderate symptoms (score=1-5), and high symptoms (score=6+). Sound speed (m/s), a surrogate of volumetric breast density, was measured with whole breast ultrasound tomography. Change in breast density was calculated as density at T1-T3 minus density at T0. We used multivariable linear regression to estimate mean change in density by endocrine symptoms adjusting for age, race, menopausal status, body mass index, and baseline sound speed. Generalized estimating equations were used to account for within-subject correlations over time.

Results: Women with treatment-associated endocrine symptoms had an overall greater mean reduction in breast density compared with women without symptoms (mean change [95% CI]: -1.97 m/s [-3.80, -0.13]; -0.27 m/s [- 3.50, 2.95], respectively; p=0.22). Longitudinal trends in breast density significantly differed for women with versus without treatment-associated endocrine symptoms (p-interaction=0.02). Significant declines in breast density over time were observed among women with treatment-associated endocrine symptoms (p-trend=0.005), but not among women without symptoms (p-trend=0.16). Similar trends in breast density decline were observed among women with higher symptom severity (p-trends for no symptoms=0.53; low/moderate symptoms=0.04; high symptoms=0.008).

Conclusions: These findings suggest that treatment-associated endocrine symptoms may be associated with a significant decline in breast density after tamoxifen initiation. Further studies are needed to assess whether these observations can predict clinical outcome, and if confirmed, both treatment-associated endocrine symptoms and observed reductions in breast density may be useful for patients and providers to improve adherence.

Citation Format: Cody Ramin, Ruth Pfeiffer, Shaoqi Fan, Maeve Mullooly, Roni T. Falk, Mark A. Sak, Michael S. Simon, David H. Gorski, Haythem Ali, Peter Littrup, Nebojsa Duric, Mark E. Sherman, Gretchen L. Gierach. Treatment-associated endocrine symptoms and change in ultrasound tomography measures of breast density after tamoxifen therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5805.

The Epidemiology of Cancer Among Homeless Adults in Metropolitan Detroit

BACKGROUND

Homeless individuals suffer and die disproportionately from chronic diseases and disorders. We describe the epidemiology of cancer among homeless persons in metropolitan Detroit.

METHODS

A retrospective cohort study was performed using 1973-2014 data from the Metropolitan Detroit Cancer Surveillance System, a population-based cancer registry and member of the National Institutes of Health-National Cancer Institute's Surveillance, Epidemiology, and End Results program. Homeless adults were identified through address at diagnosis listed as a homeless shelter, hospital, or supplemental field indicating homelessness. Age-adjusted, sex-specific proportional incidence ratios (PIR) compared cancer incidence proportions by primary tumor site of homeless patients to the nonhomeless referent population. Kaplan-Meier curves depicted unadjusted survival differences in a propensity score matched sample. Differences in 10-year survival were assessed using the score test with a sandwich estimator accounting for matched cluster effects. Statistical tests were two-sided.

RESULTS

A total of 388 individuals experienced homelessness at first primary invasive cancer diagnosis. Statistically significantly higher proportions of respiratory system (PIR = 1.51; 95% confidence interval = 1.28 to 1.79) and female genital system (PIR = 1.83; 95% confidence interval = 1.31 to 2.55) cancers were observed among homeless men and women, respectively. Homeless persons had poorer overall and cancer-reported survival compared with a propensity score matched referent population (median: overall survival, 20.0 vs 38.0 months, respectively, P < .001; cancer-reported survival, 38.0 vs 64.0 months, respectively, P  < .001).

CONCLUSION

Disparities in disease burden exist between adults who are experiencing homelessness compared with the nonhomeless population at cancer diagnosis. These findings provide clinically relevant information to understand the cancer burden in this medically underserved population and suggest an urgent need to develop cancer prevention and intervention programs to reduce disparities and improve the health of homeless persons.

IgA Fc-folate conjugate activates and recruits neutrophils to directly target triple-negative breast cancer cells

PURPOSE

According to the American Cancer Society, 1 in 8 women in the U.S. will develop breast cancer, with triple-negative breast cancer (TNBC) comprising 15-20% of all breast cancer cases. TNBC is an aggressive subtype due to its high metastatic potential and lack of targeted therapy. Recently, folate receptor alpha (FRA) is found to be expressed on 80% of TNBC with high expression correlating with poor prognosis. In this study, we examined whether binding IgA Fc-folate molecules to FRA receptors on TNBC cells can elicit and induce neutrophils (PMNs), by binding their FcαR1 receptors, to destroy TNBC cells.

METHODS

FRA was analyzed on TNBC cells and binding assays were performed using ³H-folate. Fc-folate was synthesized by linking Fc fragments of IgA via amine groups to folate. Binding specificity and antibody-dependent cellular cytotoxicity (ADCC) potential of Fc-folate to FcαR1 were confirmed by measuring PMN adhesion and myeloperoxidase (MPO) release in a cell-based ELISA. Fc-folate binding to FRA-expressing TNBC cells inducing PMNs to destroy these cells was determined using ⁵¹Cr-release and calcein-labeling assays.

RESULTS

Our results demonstrate expression of FRA on TNBC cells at levels consistent with folate binding. Fc-folate binds with high affinity to FRA compared to whole IgA-folate and induces MPO release from PMN when bound to FcαR1. Fc-folate inhibited binding of ³H-folate to TNBC cells and induced significant cell lysis of TNBC cells when incubated in the presence of PMNs.

CONCLUSION

These findings support the hypothesis that an IgA Fc-folate conjugate can destroy TNBC cells by eliciting PMN-mediated ADCC.

Racial Differences in 21-Gene Recurrence Scores Among Patients With Hormone Receptor-Positive, Node-Negative Breast Cancer

Purpose The 21-gene recurrence score (RS) breast cancer assay is clinically used to quantify risk of 10-year distant recurrence by category (low, < 18; intermediate, 18 to 30; high, ≥ 31) for treatment management among women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative, lymph node-negative breast cancer. Although non-Hispanic black (NHB) women have worse prognosis compared with non-Hispanic white (NHW) women, the equivalency of 21-gene RS across racial groups remains unknown. Patients and Methods Using the Metropolitan Detroit Cancer Surveillance System, we identified women who were diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative, lymph node-negative invasive breast cancer between 2010 and 2014. Multinomial logistic regression was used to quantify racial differences in 21-gene RS category. Results We identified 2,216 women (1,824 NHW and 392 NHB) with invasive breast cancer who met clinical guidelines for and underwent 21-gene RS testing. The mean RS was significantly higher in NHBs compared with NHWs (19.3 v 17.0, respectively; P = .0003), where NHBs were more likely to present with high-risk tumors compared with NHWs (14.8% v 8.3%, respectively; P = .0004). These differences were limited to patients younger than 65 years at diagnosis, among whom NHBs had significantly higher RS compared with NHWs (20 to 49 years: 23.6 v 17.3, respectively; P < .001 and 50 to 64 years: 19.6 v 17.4, respectively; P = .023). NHBs remained more likely to have high-risk tumors compared with NHWs after adjusting for age, clinical stage, tumor grade, and histology (odds ratio [OR], 1.75; 95% CI, 1.18 to 2.59). Conclusion NHBs who met clinical criteria for 21-gene RS testing had tumors with higher estimated risks of distant recurrence compared with NHWs. Further study is needed to elucidate whether differences in recurrence are observed for these women, which would have clinical implications for 21-gene RS calibration and treatment recommendations in NHB patients.

Riluzole synergizes with paclitaxel to inhibit cell growth and induce apoptosis in triple-negative breast cancer

PURPOSE

One in eight women will develop breast cancer, 15-20% of whom will have triple-negative breast cancer (TNBC), an aggressive breast cancer with no current targeted therapy. We have demonstrated that riluzole, an FDA-approved drug for treating amyotrophic lateral sclerosis, inhibits growth of TNBC. In this study, we explore potential synergism between riluzole and paclitaxel, a chemotherapeutic agent commonly used to treat TNBC, in regulating TNBC proliferation, cell cycle arrest, and apoptosis.

METHODS

TNBC cells were treated with paclitaxel and/or riluzole and synergistic effects on cell proliferation were quantified via MTT assay and CompuSyn analysis. Apoptosis was observed morphologically and by measuring cleaved PARP/caspase three products. Microarray analysis was performed using MDA-MB-231 cells to examine cell cycle genes regulated by riluzole and any enhanced effects on paclitaxel-mediated cell cycle arrest, determined by FACS analysis. These results were confirmed in vivo using a MDA-MB-231 xenograft model.

RESULTS

Strong enhanced or synergistic effects of riluzole on paclitaxel regulation of cell cycle progression and apoptosis was demonstrated in all TNBC cells tested as well as in the xenograft model. The MDA-MB-231, SUM149, and SUM229 cells, which are resistant to paclitaxel treatment, demonstrated the strongest synergistic or enhanced effect. Key protein kinases were shown to be upregulated in this study by riluzole as well as downstream cell cycle genes regulated by these kinases.

CONCLUSIONS

All TNBC cells tested responded synergistically to riluzole and paclitaxel strongly suggesting the usefulness of this combinatorial treatment strategy in TNBC, especially for patients whose tumors are relatively resistant to paclitaxel.

Variation in the use of advanced imaging at the time of breast cancer diagnosis in a statewide registry

BACKGROUND

Although national guidelines do not recommend extent of disease imaging for patients with newly diagnosed early stage breast cancer given that the harm outweighs the benefits, high rates of testing have been documented. The 2012 Choosing Wisely guidelines specifically addressed this issue. We examined the change over time in imaging use across a statewide collaborative, as well as the reasons for performing imaging and the impact on cost of care.

METHODS

Clinicopathologic data and use of advanced imaging tests (positron emission tomography, computed tomography, and bone scan) were abstracted from the medical records of patients treated at 25 participating sites in the Michigan Breast Oncology Quality Initiative (MiBOQI). For patients diagnosed in 2014 and 2015, reasons for testing were abstracted from the medical record.

RESULTS

Of the 34,078 patients diagnosed with stage 0-II breast cancer between 2008 and 2015 in MiBOQI, 6853 (20.1%) underwent testing with at least 1 imaging modality in the 90 days after diagnosis. There was considerable variability in rates of testing across the 25 sites for all stages of disease. Between 2008 and 2015, testing decreased over time for patients with stage 0-IIA disease (all P < .001) and remained stable for stage IIB disease (P = .10). This decrease in testing over time resulted in a cost savings, especially for patients with stage I disease.

CONCLUSION

Use of advanced imaging at the time of diagnosis decreased over time in a large statewide collaborative. Additional interventions are warranted to further reduce rates of unnecessary imaging to improve quality of care for patients with breast cancer. Cancer 2017;123:2975-83. © 2017 American Cancer Society.

Clinical and nonclinical factors associated with confirmatory biopsy in metastatic breast cancer

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Background: In patients with metastatic breast cancer, clinical practice guidelines include obtaining histologic confirmation of metastases when possible. The purpose of this study was to investigate patterns and correlates of receipt of a confirmatory biopsy. Methods: Data were abstracted from the records of patients diagnosed with metastatic breast cancer in the Michigan Breast Oncology Quality Initiative (MiBOQI), a statewide registry of 25 health systems. Patients with Stage IV disease at diagnosis were excluded. Analyses investigated associations between receipt of a confirmatory biopsy and disease, clinical and non-clinical factors, and treating health system. Results: Data were available for 1,231 (96%) of eligible patients between 2006 and 2015. Of these, 66% had a confirmatory biopsy; the proportion of patients having a biopsy varied between the 25 sites from 41% to 100% (p = 0.03). In bivariate analyses, younger age (p = 0.02), lower comorbidity (p = 0.007), longer time between the primary and recurrence (p < 0.001), more recent year of recurrence (p = 0.01), having liver, skin, soft tissue, or multiple metastases (p < 0.001), and private or government insurance (p = 0.002) were associated with biopsy. In multivariate analyses, longer time since the primary diagnosis (p < 0.001), more recent year of recurrence (p = 0.03), initial site(s) of recurrence (p < 0.001), and private or government insurance (p = 0.004) remained significant predictors of biopsy. Treatment site was no longer significant (p = 0.14). Minority status, obesity status, and disease characteristics (stage, estrogen receptor, progesterone receptor, HER2, grade) of the primary were not significant in either bivariate or multivariate analyses. Analyses were repeated without insurance with no change in the other findings. Conclusions: In a statewide collaborative, the proportion of patients having a confirmatory biopsy increased over the study period and was associated with several clinical factors. Insurance was an independent and significant predictor of receipt of what is considered standard care.

Site variation in assessment of biomarkers on biopsy specimens in patients with metastatic disease

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Background: Clinical practice guidelines in patients with metastatic breast cancer recommend assessment of biomarkers—estrogen receptors (ER), progesterone receptors (PR), and HER2—on metastatic lesions. The purpose of this study was to identify factors associated with assessment of these biomarkers in patients who had undergone confirmatory biopsies. We were particularly interested in variation between treatment sites. Methods: Eligible patients were those diagnosed with metastatic breast cancer who had undergone a confirmatory biopsy and who were part of the Michigan Breast Oncology Quality Initiative (MiBOQI) registry, a statewide registry of 25 health systems. Analyses investigated associations between assessment of ER, PR, HER2 and treating center, disease, clinical and non-clinical factors. Results: Between 2006 and 2015, 805 patients had a confirmatory biopsy. Of these, 66% had ER, 63% had PR, 62% had HER2, and 57% had all three assessed on the biopsy specimen. In bivariate analysis, characteristics associated with assessment of biomarkers were earlier stage and hormone receptor-positive primary tumors, private or military insurance, white race, longer time since initial diagnosis, and bone only, liver only, lung only, chest wall, skin, and lymph nodes, and multiple sites of metastases. Younger age was positively associated with assessment of HER2. Biomarker assessment also varied significantly between treatment sites and increased over time. In multivariate analyses, time since diagnosis of the primary (p < 0.001) and treatment site (p < 0.001) remained significant. With the exception of ER (p = 0.09), performance of biomarkers increased significantly over time. Conclusions: Across 25 health systems in a quality improvement collaborative, the proportion of patients with metastatic disease who underwent a confirmatory biopsy increased over time. Nonetheless, treatment site continued to be independently associated with the odds of having biomarkers assessed on biopsy specimens. Our findings suggest that there are opportunities for improvement to provide guideline-concordant care in patients treated in diverse settings.

Abstract P1-10-08: Factors affecting the administration of post-mastectomy radiation therapy (PMRT) in Michigan

Background: Evidence-based guidelines for locoregional therapy of invasive breast cancer treated with mastectomy include adjuvant PMRT for: ≥4 positive axillary lymph nodes (LN); T3 or above; or a positive surgical margin. We assessed PMRT uptake using data from the Michigan Breast Oncology Quality Initiative (MiBOQI), a Blue Cross Blue Shield of Michigan/Blue Care Network-sponsored collaborative quality initiative, and identified factors influencing its use in Michigan.

Methods: We prospectively collected clinical data on all patients with stage I-III breast cancer in 25 health systems belonging to MiBOQI and identified patients who underwent mastectomy from 2008 to 2013. Patients with previous cancer, bilateral disease, or treated with neoadjuvant chemotherapy were excluded. Univariate and multivariate analyses were performed to identify independent factors associated with the use of PMRT in patients with 0, 1-3, and 4+ positive LNs. Covariates included age, hormone receptor status, HER2 status, surgical margin, T category, Charlson comorbidity index, and immediate reconstruction. Two-tailed p-values &lt;0.05 were considered significant. Analyses were carried out using SAS software, version 9.4 (SAS Institute, Cary, NC).

Results: We identified 6,596 patients with stage I-III invasive breast cancer. Of these, 4,455 had no positive axillary LNs; 1,481, 1-3 positive LNs; and 660, ≥4 positive LNs. There was wide variation in PMRT use across MiBOQI sites, from 13% to 63.% in patients with 1-3 positive LNs (overall 42%) and from 35% to 91% in patients with 4+ positive LNs (overall 69%). In multivariate analyses stratified by nodal status (0, 1-3, 4+), age ≥ 70 yrs was negatively associated with PMRT. We also noted lower PMRT use in women aged 51-69 with 0 and 1-3 positive LNs (Table 1).

Table 1. Multivariate analysis: PMRT and age (+)LNs = 0(+)LNs = 1-3(+)LNs ≥ 4AgeOdds ratiop-valueOdds ratiop-valueOdds ratiop-value≤50 y (reference)1.0 1.0 1.0 51-69 y0.70 (0.49 - 0.98)0.030.69 (0.54 - 0.88)&lt;0.00011.03 (0.63 - 1.65)&lt;0.0001≥70 y0.60 (0.37 - 0.96) 0.26 (0.18 - 0.37) 0.31 (0.18 - 0.54) 

In the 0 and 1-3 positive node groups, PMRT use was strongly associated with T category and close or positive margin status (Table 2).

Table 2: Surgical characteristics and PMRT uptake (+)LNs = 0(+)LNs = 1-3(+)LNs ≥4VARIABLEOdds ratiop-valueOdds ratiop-valueOdds ratiop-valueMargin status      Negative (reference)1.0 1.0 1.0 Positive16.7 (10.5 - 26.7)&lt;0.00012.27 (1.32 - 3.90)0.0010.69 (0.32 - 1.47)0.90Close (&lt;1 mm)4.63 (3.03 - 7.10) 1.90 (1.29 - 2.80) 0.97 (0.55 - 1.69)        T category      T0 to T2 (reference)1.0 1.0 1.0 T3 to T426.2 (16.4 - 41.8)&lt;0.00013.24 (2.19 - 4.78)&lt;0.00010.86 (0.57 - 1.28)0.45

Finally, there was no association between PMRT use and hormone receptor status, HER2 status, Charlson comorbidity index, or reconstructive surgery at the time of mastectomy.

Conclusions: PMRT use across Michigan was lower than the American College of Surgeons Commission on Cancer target of 90% in patients with 4 or more positive LNs. Contrary to common belief, immediate reconstructive surgery was not independently associated with decreased PMRT uptake. Understanding reasons for nonuse of PMRT may lead to interventions to increase its use by MiBOQI member institutions in patients for whom it is indicated.

Citation Format: Gorski DH, Braun T, Munir K, Griggs JJ, Breslin TM, Henry NL. Factors affecting the administration of post-mastectomy radiation therapy (PMRT) in Michigan [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 P1-10-08.

HER2 status and disparities in luminal breast cancers

National Comprehensive Care Network guidelines for adjuvant treatment of invasive breast cancer are based on HER2 and hormone receptor (HR) status, where HR+ disease encompasses all estrogen receptor (ER)+ and/or progesterone receptor (PR)+ tumors. We sought to explore clinical and demographic differences among patients with HR+ breast cancer subtypes, and the role of HER2 status, age, race/ethnicity, and socioeconomic status (SES) in disease risk. We evaluated breast cancer subtype distribution, defined by HR and HER2 status, using patient clinical, demographic, and socioeconomic characteristics. Differences in HR categories by demographic and tumor characteristics were examined using chi-squared tests. Multinomial logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) to quantify associations between breast cancer HR status and demographic factors. We found that differences in HR+ (ER-/PR+ vs. ER+/PR- or ER+/PR+) tumor biology are likely clinically significant and may play a role in breast cancer, regardless of HER2 status. While clinical and patient characteristics differed within each luminal subtype, we found disparities in SES only among Luminal A (HR+/HER2-) tumors. Among HR+/HER2- cases, we observed that ER-/PR+ patients tend to live in areas of higher poverty (OR = 1.20, 95% CI = 1.03-1.40) and are 70% more likely to be aged 50 years or older. However, this pattern was not found in women with Luminal B (HR+/HER2+) disease (Poverty OR = 0.98, 95% CI = 0.76-1.27; Age OR = 1.01, 95% CI = 0.81-1.26). Racial/ethnic disparities among non-Hispanic black and Hispanic women persisted across HR+/HER2- cases compared to non-Hispanic white women. Our findings suggest that while race/ethnicity and SES are correlated, each plays an independent role in contributing to disease among Luminal A tumors. Further study is needed to investigate how tumor biology, race/ethnicity, and socioeconomic disparities among HR+/HER2- cases may contribute to poorer patient prognosis.

Unwarranted variation in time to initiation of adjuvant chemotherapy in a statewide collaborative

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Background: The purpose of this study was to investigate clinical and non-clinical factors associated with time to initiation of breast cancer adjuvant chemotherapy following the final definitive surgery in a state-wide collaborative. Methods: We collected prospective data from all patients who received adjuvant chemotherapy for Stages I - III breast cancer in 25 health systems in the Michigan Breast Oncology Quality Initiative (MiBOQI) between 2006 - 2014. MiBOQI is a Blue Cross Blue Shield of Michigan/Blue Care Network-sponsored quality collaborative. The dependent variable was time to initiation of adjuvant chemotherapy. Time to chemotherapy was examined according to clinical and non-clinical patient and treatment factors and by health system, both with and without adjustment for patient and treatment variables. Results: Complete data were available for 7,513 of 8,236 eligible (91%) patients. The mean time to chemotherapy was 43 days (range 5-390). In multivariate analyses, clinical factors independently associated with longer time to chemotherapy included increasing age, greater comorbidity, and obesity (p value < 0.0001 for all). Higher stage disease was associated with shorter time to chemotherapy (p < 0.0001); there was no association with hormone receptor or HER2 status. Treatment factors associated with longer time to chemotherapy were breast reconstruction, receipt of genomic assays, and receipt of advanced imaging (p value < 0.0001 for all). Non-clinical factors—minority status, higher area-level poverty, and non-private insurance—were also independently associated with longer time to chemotherapy (p value < 0.0001 for all). In addition, time to chemotherapy varied significantly between health system (p < 0.0001); this difference persisted after adjustment for all patient and treatment factors. Conclusions: Clinical and non-clinical factors, including site of care, are associated with variation in time to initiation of chemotherapy. Identifying patient-level factors and processes of care that facilitate or impede timely initiation of chemotherapy may decrease unwarranted variation in care delivery across a collaborative network.

Variation in use of advanced imaging at the time of breast cancer diagnosis in a statewide registry

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Background: Advanced imaging for diagnosis of metastatic disease at the time of diagnosis of stage 0-II breast cancer is not recommended according to national guidelines. The purpose of this study was to examine the variation in ordering of CT chest, abdomen, and pelvis, PET, and bone scans across the state of Michigan, and to investigate clinical and non-clinical factors associated with test ordering. Methods: We prospectively collected data from all patients diagnosed with stage 0-II breast cancer from 2008-2014 in 25 health systems in the Michigan Breast Oncology Quality Initiative (MiBOQI), a Blue Cross Blue Shield of Michigan/Blue Care Network-sponsored quality initiative. Demographic, imaging, and pathologic data were abstracted from the medical record. The primary endpoint was the percentage of patients with at least one advanced imaging test performed within 90 days after diagnosis of breast cancer. Analyses were performed using the chi-squared test of association. Results: Of the 27,011 patients, 4799 (17.8%) had at least one staging exam performed within 90 days of diagnosis. Imaging tests were primarily performed post-operatively. The average percentage of patients who had at least one staging exam performed varied by stage and by site (Table). The rate of testing decreased over time for stage 0-IIA cancers but not for stage IIB. On multivariate analysis, younger age, black race, hormone receptor negativity, HER2 positivity, and higher grade were associated with increased likelihood of undergoing imaging. Conclusions: There is considerable variability in ordering of staging scans at the time of diagnosis of early stage breast cancer across Michigan. Factors underlying use of imaging in stage IIB disease should be examined in order to develop interventions for rate reduction. [Table: see text]

Abstract P5-08-07: Appropriate use of the 21-gene recurrence score (RS) assay across Michigan

Background: The 21-gene RS assay is used to assess prognosis and to predict response to adjuvant chemotherapy in patients with early stage hormone receptor positive, Her2 negative invasive breast cancer. The National Comprehensive Cancer Network (NCCN) first recommended consideration of testing of appropriate patients with the RS assay in 2008. We examined trends in the use of testing with the RS assay in hospitals across Michigan from 2006 through 2013 using data from the Michigan Breast Oncology Quality Initiative (MiBOQI), a Blue Cross Blue Shield of Michigan/Blue Care Network-sponsored quality initiative.

Methods: Demographic, pathologic, and treatment data for women with breast cancer treated at all 25 hospitals participating in MiBOQI were abstracted from the medical record. Patients were excluded if they had stage 0 or IV disease at diagnosis, received neoadjuvant therapy, had bilateral breast cancer, or had a prior history of breast cancer. The primary outcome was the percentage of patients eligible for testing according to NCCN criteria (version 2010) who underwent testing with the RS assay. Analyses were performed using the statistical software R, Version 3.0.1.

Results: Of the 18,046 patients in the MiBOQI Registry from 2006-2013 who met inclusion and exclusion criteria, 7133 (39.5%) met the NCCN criteria for testing (eligible). The rate of testing increased from 2006 to 2013 in both the eligible and ineligible cohorts, and varied by site.

21-Gene Recurrence Score (RS) Testing in MiBOQI, 2006-2013FactorEligible (n=7133)Ineligible (n=10913)Tested with RS assay3920 (55.5%)1424 (13.0%)Testing rate in 200643.8%7.3%Testing rate in 201362.3%19.6%Testing by site, 2006-2013 (range)35.8% - 73.3%6.8% - 26.2%

Testing of the eligible cohort was statistically significantly associated with younger age, lower tumor grade, and lack of nodal involvement. Overall, 73.4% of patients whose tumors were tested with the RS assay met the NCCN criteria for testing and were deemed appropriately tested. This rate of appropriate testing ranged from 60.8% to 85.4% across sites. Of all patients who underwent testing, 498 (9.3%) had 1 or more positive lymph nodes (&gt;0.2 cm). Receipt of chemotherapy was lower in eligible patients who were tested compared to those not tested (25.5% vs 29.9%, p&lt;0.001). Of the 2387 eligible patients with RS &lt; 18, 117 (5.5%) received chemotherapy, which ranged from 0% - 13.6% across the 25 sites. Of the 341 patients with RS &gt; 30, 56 (9.8%) did not receive treatment with chemotherapy, which ranged from 0% - 50% across the sites. Of the 1192 patients with RS 18-30, 502 (45.7%) received chemotherapy, ranging from 14.5% for RS 18 to 72.5% for RS 30.

Conclusions: In sites across Michigan the majority of patients whose tumors were tested with the RS assay were in accordance with the NCCN guidelines, although there was considerable variability across sites. The rate of testing for patients who do not meet the NCCN criteria is increasing. There is very low inappropriate use of the recurrence score for making chemotherapy treatment decisions.

Citation Format: Ali HY, Munir K, Braun T, Griggs JJ, Silver SM, Gorski DH, Breslin TM, Henry NL. Appropriate use of the 21-gene recurrence score (RS) assay across Michigan. [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 P5-08-07.

PDGFRα and β play critical roles in mediating Foxq1-driven breast cancer stemness and chemoresistance

Many epithelial-mesenchymal transition (EMT)-promoting transcription factors have been implicated in tumorigenesis and metastasis as well as chemoresistance of cancer. However, the underlying mechanisms mediating these processes are unclear. Here, we report that Foxq1, a forkhead box-containing transcription factor and EMT-inducing gene, promotes stemness traits and chemoresistance in mammary epithelial cells. Using an expression profiling assay, we identified Twist1, Zeb2, and PDGFRα and β as Foxq1 downstream targets. We further show that PDGFRα and β can be directly regulated by Foxq1 or indirectly regulated through the Foxq1/Twist1 axis. Knockdown of both PDGFRα and β results in more significant effects on reversing Foxq1-promoted oncogenesis in vitro and in vivo than knockdown of either PDGFRα or β alone. In addition, PDGFRβ is a more potent mediator of Foxq1-promoted stemness traits than PDGFRα. Finally, pharmacologic inhibition or gene silencing of PDGFRs sensitizes mammary epithelial cells to chemotherapeutic agents in vitro and in vivo. These findings collectively implicate PDGFRs as critical mediators of breast cancer oncogenesis and chemoresistance driven by Foxq1, with potential implications for developing novel therapeutic combinations to treat breast cancer.

Abstract 4608: Exploring anti-oncogenic properties of riluzole in breast cancer

Introduction: Triple negative breast cancer (TNBC) is a subtype of breast cancer that lacks the three receptors that current therapy targets (estrogen (ER), progesterone, HER2). Because of this, it is a very aggressive type of breast cancer with a high mortality rate. In a previous study, we discovered the drug, riluzole, to be an mGluR1 inhibitor and to reduce cell proliferation and tumor growth in triple negative breast cancer (TNBC), resulting in apoptosis. This was a significant finding because there are currently no major therapies available to successfully treat TNBC. It is now being thought that riluzole also has properties that may allow it to act as a therapy against ER-positive breast cancer (ER+).

Methods: The goal of this study was to learn more about how riluzole functions by analyzing the anti-oncogenic properties of riluzole. To do this, we conducted a series of transformation assays including cell proliferation (MTT), invasion, soft agar, adhesion, and in vivo metastasis using 4T1-12B cells (a luciferase-expressing clone of the 4T1 mouse mammary tumor cell line).

Results: The results of the assays completed thus far indicate that both TNBC and ER+ cells are sensitive to riluzole, with TNBC being more sensitive. Riluzole significantly inhibits invasion of TNBC cells but not ER+ cells. These findings are consistent with the previous study's results showing that riluzole targets mGluR1 pathways, since ER+ cells contain significantly smaller amounts of mGluR1 compared to TNBC cells. Additionally, riluzole inhibits both cell proliferation and anchorage independent growth of both cell types, suggesting both mGluR1 dependent and independent pathways are involved.

Conclusion: The results of this study suggest that riluzole can be developed as an anti-breast cancer therapy for both triple negative and ER-positive breast cancer patients. Further studies silencing mGluR1 in TNBC and overexpressing mGluR1 in ER+ cell lines will help to determine any significance of mGluR1 in mediating riluzole's mechanism of action.

Citation Format: Miriam A. Bukhsh, Cecilia L. Speyer, Ali A. Hachem, Mahdy Nassar, Ali A. Assi, David H. Gorski. Exploring anti-oncogenic properties of riluzole in breast cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4608. doi:10.1158/1538-7445.AM2014-4608

Integrative oncology: really the best of both worlds?

Over the past two decades there has been a growing acceptance of 'integrative oncology', also known as complementary and alternative medicine (CAM), in cancer care and research at academic medical centres and medical schools. Proponents of integrative oncology argue that it is based in science and provides the 'best of both worlds' by combining science-based treatments and 'holistic' medicine. However, a close examination of the methodologies indicates that, from a standpoint of basic science, the vast majority of 'integrative' treatments are supported by little, if any, scientific evidence. What are the consequences of this integration? Is there any harm? Are there any potential benefits?

Clinical trials of integrative medicine: testing whether magic works?

Over the past two decades complementary and alternative medicine treatments relying on dubious science have been embraced by medical academia. Despite low to nonexistent prior probability that testing these treatments in randomized clinical trials (RCTs) will be successful, RCTs of these modalities have proliferated, consistent with the principles of evidence-based medicine, which underemphasize prior plausibility rooted in science. We examine this phenomenon and argue that what is needed is science-based medicine rather than evidence-based medicine.

Metabotropic glutamate receptor-1 as a novel target for the antiangiogenic treatment of breast cancer

Metabotropic glutamate receptors (mGluRs) are normally expressed in the central nervous system, where they mediate neuronal excitability and neurotransmitter release. Certain cancers, including melanoma and gliomas, express various mGluR subtypes that have been implicated as playing a role in disease progression. Recently, we detected metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in breast cancer and found that it plays a role in the regulation of cell proliferation and tumor growth. In addition to cancer cells, brain endothelial cells express mGluR1. In light of these studies, and because angiogenesis is both a prognostic indicator in cancer correlating with a poorer prognosis and a potential therapeutic target, we explored a potential role for mGluR1 in mediating endothelial cell (EC) proliferation and tumor-induced angiogenesis. GRM1 and mGluR1 were detected in various types of human ECs and, using mGluR1-specific inhibitors or shRNA silencing, we demonstrated that EC growth and Matrigel tube formation are dependent on mGluR1 signaling. In addition, loss of mGluR1 activity leads to reduced angiogenesis in a murine Matrigel sponge implant model as well as a murine tumor model. These results suggest a role for mGluR1 in breast cancer as a pro-angiogenic factor as well as a mediator of tumor progression. They also suggest mGluR1 as a potential new molecular target for the anti-angiogenic therapy of breast cancer.

Next-generation sequencing: a powerful tool for the discovery of molecular markers in breast ductal carcinoma in situ

Mammographic screening leads to frequent biopsies and concomitant overdiagnosis of breast cancer, particularly ductal carcinoma in situ (DCIS). Some DCIS lesions rapidly progress to invasive carcinoma, whereas others remain indolent. Because we cannot yet predict which lesions will not progress, all DCIS is regarded as malignant, and many women are overtreated. Thus, there is a pressing need for a panel of molecular markers in addition to the current clinical and pathological factors to provide prognostic information. Genomic technologies such as microarrays have made major contributions to defining subtypes of breast cancer. Next-generation sequencing (NGS) modalities offer unprecedented depth of expression analysis through revealing transcriptional boundaries, mutations, rare transcripts and alternative splice variants. NGS approaches are just beginning to be applied to DCIS. Here, the authors review the applications and challenges of NGS in discovering novel potential therapeutic targets and candidate biomarkers in the premalignant progression of breast cancer.

Abstract 3895: Metabotropic glutamate receptor-1 as a novel target for the anti-angiogenic treatment of breast cancer

Introduction: Metabotropic glutamate receptors (mGluRs) are normally expressed in the central nervous system where they mediate neuronal excitability and neurotransmitter release. However, certain cancers including melanoma and gliomas, have been shown to express various mGluR subtypes. Recently, we detected the metabotropic glutamate receptor-1 subtype (gene: GRM1; protein: mGluR1) in breast cancer and have demonstrated its role in the regulation of cell proliferation and tumor growth. In addition to cancer cells, brain endothelial cells have been shown to express mGluR1. In light of these studies and since angiogenesis is a known prognostic indicator of early relapse in cancer correlating with a poorer prognosis, we wished to examine a potential role for mGluR1 in mediating endothelial cell proliferation and angiogenesis in breast cancer.

Methods: To do this, we analyzed several primary endothelial cells for mGluR1 protein and mRNA expression and looked at their potential role in mediating cell proliferation and angiogenesis using various mGluR1 inhibitors or by silencing the gene for mGluR1 (GRM1). Cell proliferation was determined by MTT analysis or by cell counting and angiogenesis was determined in vitro using the matrigel tube formation assay. Angiogenesis was also determined in vivo using human dermal micro-endothelial cells (HDMEC) embedded in a matrigel sponge and implanted into the flanks of nude mice treated with the mGluR1 inhibitors, BAY36-7620 or Riluzole. The role of mGluR1 in mediating tumor-induced angiogenesis was also examined using the 4T1 tumor model in the presence of these same inhibitors.

Results: We detected mRNA and protein expression of mGluR1 in various human endothelial cells and, using mGluR1-specific inhibitors, have demonstrated its ability to regulate cell growth as well as matrigel tube formation. Both BAY36-7620 and Riluzole inhibited cell growth and matrigel tube formation in a dose-response manner. BAY36-7620, which is a more specific-inhibitor than Riluzole, inhibited tube formation by almost 90% compared to 50% by Riluzole, at the highest doses tested. These results were confirmed using mGluR1-silenced cells. In addition, both BAY36-7620 and Riluzole inhibited angiogenesis in the in vivo matrigel sponge model by approximately 50% each, compared to vehicle treated mice.

Conclusion: These results suggest a role for mGluR1 in the development and progression of breast cancer and thus, provide a potential new molecular target for the anti-angiogenic treatment of breast cancer.

Citation Format: Cecilia L. Speyer, Ali H. Hachem, Ali Assi, John A. DeVries, David H. Gorski. Metabotropic glutamate receptor-1 as a novel target for the anti-angiogenic treatment of breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3895. doi:10.1158/1538-7445.AM2013-3895

Abstract 1206: Metabotropic glutamate receptor 1 functions as an oncogene in the progression of triple negative breast cancer

Introduction: L-glutamate is the major excitatory neurotransmitter in the central nervous system and activates both ionotropic and metabotropic glutamate receptors. The metabotropic glutamate receptors (mGluRs) are a family of G protein-coupled receptors. mGluR1 (gene: GRM1) is included in Group I of these receptors and have been shown to activate phosphatidylinositol-calcium second messenger system. Aberrant extracellular glutamate signaling has been implicated in carcinogenesis; specifically, the aberrant expression of mGluR1 in melanocytes plays a critical role in the development of melanoma. Previously in our laboratory, we detected mGRM1 expression in triple negative breast cancer cells. We therefore evaluated its role in regulating the phenotype of these cells and found that mGluR1 expression is oncogenic in triple negative breast cancer (TNBC) progression. Methods: We determined the role of mGluR1 in TNBC progression using the MCF-10 triple negative series of cell lines, which represent the progression from normal mammary epithelium (MCF10A) to atypical hyperplasia (MCF10AT1) to ductal carcinoma in situ (MCF10.DCIS.com), and finally to malignant (MCF10.CA1D). GRM1 was overexpressed in MCF10A and MCF10AT1 and silenced MCF10.DCIS.com and MCF10.CA1D. We then determined whether mGRM1 has a transforming role through in vitro studies of proliferation, invasion, migration and anchorage-independent growth. We also inhibited mGluR1 signaling using two pharmacologic inhibitors: Riluzole, which is FDA-approved for amyotropic lateral sclerosis, and BAY36-7620, which is a specific noncompetitive inhibitor of mGluR1. Effects were evaluated on proliferation and anchorage independent growth. Finally, MCF10AT1 cells were transduced with a lentiviral construct driving mGluR1 expression and injected into athymic nude mice. The growth and histology of the resultant xenografts were compared with control LacZ transduced cells. Results: mGluR1 overexpression increased proliferation, anchorage-independent growth, and invasiveness in MCF10AT1 and not in MCF10A cells, while knockdown of mGluR1 expression resulted in a decrease in proliferation, anchorage independent growth and invasiveness in MCF10.CA1D cells. Pharmacologic inhibition of mGluR1 signaling in MCF10.CA1D cells resulted in a decrease in proliferation and anchorage independent growth. Transduction of MCF10AT1 cells with GRM1 resulted in transformation to carcinoma in 10/11 of the resultant xenografts compared to 2/9 for wild type and 3/11 for LacZ controls. Conclusions: mGluR1 expression and activity increases cell proliferation, anchorage independent growth, and invasion in vitro. In vivo, mGluR1 drives progression of MCF10AT1 cells from hyperplastic lesions to frank carcinoma. We therefore conclude that mGRM1 plays a role of an oncogene in the progression of TNBC and represents a therapeutic target.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1206. doi:1538-7445.AM2012-1206

Metabotropic glutamate receptor-1: a potential therapeutic target for the treatment of breast cancer

Metabotropic glutamate receptors are G-protein-coupled receptors normally expressed in the central nervous system where they mediate neuronal excitability, synaptic plasticity, and feedback inhibition of neurotransmitter release. However, recent data suggest that these receptors are also expressed and functional in some cancers, most notably melanoma. We detected the expression of metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in triple negative breast cancer cells and evaluated its role in regulating the pro-proliferative phenotype of these cells. mGluR1 inhibitors (Riluzole or BAY36-7620) inhibited the proliferation of triple negative breast cancer cells in a time- and dose-dependent manner and this inhibition correlated with increased apoptosis as demonstrated by increase in PARP cleavage products and Annexin V staining. mGluR1 knockdown using Lentiviral constructs expressing shRNA targeting GRM1 also inhibited proliferation compared to non-silencing controls. In addition, treatment of mice bearing MDA-MB-231 xenografts with Riluzole or BAY36-7620, by intraperitoneal injection, resulted in a significant reduction in tumor volume of up to 80%. Moreover, Riluzole was effective against triple negative breast cancer xenografts in mice at doses equivalent to those currently being used in humans for the treatment of amyotrophic lateral sclerosis. Our observations implicate mGluR1 and glutamate signaling as a promising new molecular target for the treatment of breast cancer. Even more promising, Riluzole, because it is an oral drug that can be administered with low toxicity, represents a promising approach in the treatment of triple negative breast cancer.

Abstract 1673: mGluR1 as a potential therapeutic target in the treatment of triple negative breast cancer

Introduction: Metabotropic glutamate receptors are expressed throughout the central nervous system where they initiate a host of signaling events that regulate neuron function. We have identified the presence of metabotropic glutamate receptor 1 (mGluR1) in breast cancer cells and demonstrated a role for these receptors in regulating the pro-proliferative phenotype of these cells, both in vitro and in vivo. In this study, we investigate the signaling mechanism(s) by which mGluR1 mediates this pro-proliferative effect, as well as investigating a potential role for mGluR1 in mediating anti-apoptotic signaling events in triple negative breast cancer.

Methods: We studied the effect of mGluR1 expression on cell growth using MDA-MB-231 cells stably transduced with plasmids expressing shRNA against GRM1, the gene coding for mGluR1 protein. Cell growth was measured by MTT assay and a role for mGluR1 in mediating apoptosis was assessed by measuring PARP cleavage products and Annexin V staining, using Riluzole or BAY36-7620 (BAY), non-competitive inhibitors of mGluR1 activity. To examine potential signaling mechanisms mediating cell growth, MDA-MB-231 cells were grown in glutamate-free media and stimulated with the mGluR1 agonist, L-Quisqualic acid, in the presence or absence of BAY. PKC and phosphorylated Akt levels were examined by Western analysis. Since mGluR1 is known to protect nerve cells from oxidative stress and increased oxidative stress can result in p53-induced apoptosis, we measured the effect of Riluzole on p53 expression and oxidative stress levels in MDA-MB-231 cells. Oxidative stress was measured using immunofluorescent staining with carboxy-H2DCFDA and p53 by Western blot analysis.

Results: MDA-MB-231 cells were transduced with Lentiviral constructs expressing shRNA against GRM1 and cell growth assessed by MTT assay. Growth of these cells was inhibited 50% by shRNA against GRM1 compared to non-silencing scrambled control. In addition, inhibition of mGluR1 activity by BAY in MDA-MB-231 cells prevented signaling through Akt which ultimately resulted in increased p53 expression and superoxide production and apoptosis. Incubation of MDA-MB-231 or BT549 cells with varying doses of Riluzole resulted in increased PARP cleavage by 24 hours. FACS analysis also showed a three- and ten-fold increase in Annexin V staining of MDA-MB-231 cells after 24 and 48 hr incubation with Riluzole, respectively. BAY also induced Annexin V staining of these cells by almost 3-fold at the 48 hr timepoint.

Conclusion: Our results showing that inhibition of mGluR1 inhibits proliferation and increases apoptosis and oxidative stress implicate mGluR1, or one of its downstream signaling molecules, as potential new molecular targets for the treatment of breast cancer. Because it is an FDA-approved oral drug with low toxicity, Riluzole represents a promising approach in the treatment of triple negative breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1673. doi:10.1158/1538-7445.AM2011-1673

Abstract 3950: The role of microRNA-130a in regulating HOXA5 expression in breast cancer progression

Introduction: Micro RNAs (miRNAs) are key post -transcriptional and translational regulators of gene expression and regulate diverse physiological activities involving development, cell growth, differentiation, apoptosis, and pathological processes such as heart disease and cancer. In tumorigenesis miRNAs function as oncogenes or tumor suppressors. HOXA5 belongs to the family of homeobox (HOX) genes, which encode a highly conserved family of transcription factors that are known to regulate body patterning during embryogenesis. HOXA5 plays a major role in mesenchymal-epithelial interactions during organogenesis. Sukumar et al have demonstrated that HOXA5 loss of function leads to loss of p53 expression in mammary epithelial cells, which in turn contributes to malignant transformation, which is why understanding the mechanisms by which HOXA5 expression is dysregulated in breast cancer is critical. We identified a consensus binding sequence for miR-130a in the 3′-UTR of the HOXA5 coding region. Previous studies in our laboratory have shown that miR-130a downregulates HOXA5 expression in vascular endothelial cells. In this study we characterize the role of miR130a in downregulating HOXA5 expression that in turn can decrease p53 expression and function in breast cancer cells resulting in tumor proliferation, progression and metastasis.

Methods: We determined whether mitogenic factors in serum affect miR130a and HOXA5 mRNA expression in the breast epithelial cell line MCF10A. Correlation between the expression of miR130a and HOXA5 mRNA expression in the MCF-10 breast progression series cell lines that model the progression from normal mammary epithelium (MCF-10A), ductal carcinoma in situ (MCF10.DCIS.com), to fully malignant (MCF10.CA1) was examined. In addition, we silenced miR-130a using a specific 2’-O-methyl-modified inhibitor and determined whether knocking it out increases HOXA5 mRNA expression in MCF10A cells. The expression levels of miR130a and HOXA5 were measured using quantitative reverse transcriptase real time PCR (QRT-PCR).

Results: First, we observed that miR130a expression increases by 2.2 fold and HOXA5 mRNA levels decreases by 0.2 fold following treatment with 5% horse serum in MCF10A cells. Next, we noted that miR-130a expression increases and HOXA5 mRNA expression decreases as tumorigenicity increases in MCF10A progression series cell lines. Finally, knocking out miR-130a activity increased HOXA5 mRNA expression in MCF10A cells, demonstrating that HOXA5 is regulated by miR130a in these cells.

Conclusion: Overall our results indicate that miR130a regulates HOXA5 in breast cancer cells and thus may have a role in breast tumor progression. This study will enable us to decipher the role of mir130a in breast tumor progression and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3950. doi:10.1158/1538-7445.AM2011-3950

MEOX2 regulates nuclear factor-kappaB activity in vascular endothelial cells through interactions with p65 and IkappaBbeta

AIMS

Tumours secrete proangiogenic factors to induce the ingrowth of blood vessels, the end targets of which are vascular endothelial cells (ECs). The MEOX2 homeoprotein inhibits nuclear factor-kappaB (NF-kappaB) signalling and EC activation in response to serum and proangiogenic factors. We hypothesize that MEOX2 interacts with components of this pathway in vascular ECs to modulate NF-kappaB activity and EC activation and that these interactions depend upon specific domains within the MEOX2 protein.

METHODS AND RESULTS

To test our hypothesis, we transduced ECs with MEOX2 expression constructs. MEOX2 protein localized to the nuclear fraction, as did IkappaBbeta and p65. By co-immunoprecipitation, MEOX2 bound to both p65 and IkappaBbeta. Immunofluorescence demonstrated that MEOX2 colocalizes in the nucleus with both p65 and IkappaBbeta and that this colocalization requires the MEOX2 homeodomain and N-terminal domain. Finally, promoter assays revealed that MEOX2 expression has a biphasic effect on NF-kappaB-dependent promoters. At low levels, MEOX2 stimulates NF-kappaB activity, whereas at high levels, it represses, effects that also depend upon the homeodomain and the N-terminal domain.

CONCLUSION

Our results represent the first report of an interaction between a homeobox protein and IkappaBbeta and suggest that MEOX2 modulates the activity of the RelA complex through direct interaction with its components. These observations implicate MEOX2 as a potentially important regulatory gene inhibiting not only the angiogenic response of ECs to proangiogenic factors, but also their response to chronic inflammatory stimulation that normally activates NF-kappaB, suggesting MEOX2 as a possible molecular target for the therapy of angiogenesis-dependent diseases such as cancer.

The homeobox gene GAX activates p21WAF1/CIP1 expression in vascular endothelial cells through direct interaction with upstream AT-rich sequences

Tumors secrete pro-angiogenic factors to induce the ingrowth of blood vessels from the surrounding stroma, the end targets of which are vascular endothelial cells (ECs). The homeobox gene GAX inhibits angiogenesis and induces p21(WAF1/CIP1) expression in vascular ECs. To elucidate the mechanism through which GAX activates p21(WAF1/CIP1) expression, we constructed GAX cDNAs with deletions of the N-terminal domain, the homeodomain, or the C-terminal domain and then assessed these constructs for their ability to activate p21(WAF1/CIP1). There was an absolute requirement for the homeodomain, whereas deleting the C-terminal domain decreased but did not abolish transactivation of the p21(WAF1/CIP1) promoter by GAX. Deleting the N-terminal domain did abolish transactivation. Next, we performed chromatin immunoprecipitation and found, approximately 15 kb upstream of the p21(WAF1/CIP1) ATG codon, an ATTA-containing GAX-binding site (designated A6) with a sequence similar to that of other homeodomain-binding sites. GAX was able to bind to A6 in a homeodomain-dependent manner and thereby activate the expression of a reporter gene coupled to this sequence, and this activation was abolished by mutating specific residues in this sequence. On the basis of the sequence of A6, we were then able to locate other ATTA-containing sequences that also bound GAX and activated transcription in reporter constructs. Finally, we found that the ability of these GAX deletions to induce G(0)/G(1) arrest correlates with their ability to transactivate the p21(WAF1/CIP1) promoter. We conclude that GAX activates p21(WAF1/CIP1) through multiple upstream AT-rich sequences. Given the multiple biological activities of GAX in regulating EC function, identification of a putative GAX-binding site will allow the study of how GAX activates or represses other downstream targets to inhibit angiogenesis.

The homeobox gene Gax inhibits angiogenesis through inhibition of nuclear factor-kappaB-dependent endothelial cell gene expression

The growth and metastasis of tumors are heavily dependent on angiogenesis, but much of the transcriptional regulation of vascular endothelial cell gene expression responsible for angiogenesis remains to be elucidated. The homeobox gene Gax is expressed in vascular endothelial cells and inhibits proliferation and tube formation in vitro. We hypothesized that Gax is a negative transcriptional regulator of the endothelial cell angiogenic phenotype and studied its regulation and activity in vascular endothelial cells. Several proangiogenic factors caused a rapid down-regulation of Gax mRNA in human vascular endothelial cells, as did conditioned media from breast cancer cell lines. In addition, Gax expression using a replication-deficient adenoviral vector inhibited human umbilical vein endothelial cell migration toward proangiogenic factors in vitro and inhibited angiogenesis in vivo in Matrigel plugs. To identify putative downstream targets of Gax, we examined changes in global gene expression in endothelial cells due to Gax activity. Gax expression resulted in changes in global gene expression consistent with a quiescent, nonangiogenic phenotype, with increased expression of cyclin kinase inhibitors and decreased expression of genes implicated in endothelial cell activation and angiogenesis. Further analysis revealed that Gax down-regulated numerous nuclear factor-kappaB (NF-kappaB) target genes and decreased the binding of NF-kappaB to its target sequence in electrophoretic mobility shift assays. To our knowledge, Gax is the first homeobox gene described that inhibits NF-kappaB activity in vascular endothelial cells. Because NF-kappaB has been implicated in endothelial cell activation and angiogenesis, the down-regulation of NF-kappaB-dependent genes by Gax suggests one potential mechanism by which Gax inhibits the angiogenic phenotype.

Detection of B-RAF and N-RAS mutations in human melanoma

BACKGROUND

It is now known that activating point mutations in components of the mitogen-activated protein kinase pathway commonly occur in melanoma. We previously described a method to detect point mutations in heterogenous tissues containing both wild-type and mutant B-RAF and N-RAS genes by using site-directed mutagenesis to introduce new restrictions sites in the cDNA sequence when the specific point mutations are present. We modified this technique to improve sensitivity and used it to determine the incidence of B-RAF and N-RAS mutations in human melanoma.

STUDY DESIGN

We screened 115 melanoma samples for the most common B-RAF and N-RAS mutations found in melanoma using a site-directed mutagenesis-based detection technique. Southern blotting was used to increase sensitivity of the basic system. We also tested this method of genetic mutation detection in fine-needle aspiration specimens and paraffin-embedded tissues.

RESULTS

Sixty-eight samples (20 of 36 primaries, 18 of 27 regional metastases, 16 of 40 nodal metastases, and 9 of 12 distant metastases) harbored the V599E B-RAF mutation (59%), 17 contained a Q61R N-RAS mutation, and 4 contained a Q61K N-RAS mutation. We were able to detect the V599E mutation in genomic DNA from paraffin-embedded melanoma samples and could routinely detect this mutation in fine-needle aspirations of melanoma tumors. This method of detection was sensitive and specific with no false positives.

CONCLUSIONS

Activating mutations of B-RAF and N-RAS were present in approximately 60% and 18%, respectively, of samples tested. The site-directed mutagenesis system of mutation detection was both sensitive and specific in detecting these mutations and will likely prove very clinically useful in future studies.

Vascular endothelial growth factor C mRNA expression correlates with stage of progression in patients with melanoma

PURPOSE

Vascular endothelial growth factor (VEGF)-C promotes the ingrowth and invasion of lymphatics in many different tumor types, including melanoma. To determine whether expression of VEGF-C correlates with stage of progression, we measured VEGF-C mRNA levels in melanomas representing different stages of progression and from the vertical and horizontal growth-phase of individual primary melanomas.

EXPERIMENTAL DESIGN

Total RNA was extracted from human melanoma specimens taken from operative specimens and subjected to quantitative real-time PCR. VEGF-C levels were determined for 54 melanoma samples, including primary melanomas (n=15), local recurrences (n=6), regional dermal metastases (n=11), nodal metastases (n=12), and distant metastases (n=10). As a surrogate for lymphatic density, we also measured the expression of the lymphatic endothelial marker LYVE-1 and correlated its expression with previously measured VEGF-C levels.

RESULTS

Vertical growth phase melanomas expressed significantly higher levels of VEGF-C than horizontal growth phase melanomas. Nodal metastases expressed the highest level of VEGF-C, followed by regional dermal metastases. Primary and local recurrences expressed a relatively low level of VEGF-C, as did negative lymph nodes and distant metastases. In addition, VEGF-C expression correlated well with LYVE-1 expression (r=0.611; P<0.0001).

CONCLUSIONS

These data suggest that high levels of VEGF-C may be important in regional lymphatic disease in melanoma and that VEGF-C and LYVE-1 levels may identify tumors with a high risk for nodal metastases, for which antilymphangiogenic therapy may be more effective.

Differential expression of vascular endothelial growth factor-A isoforms at different stages of melanoma progression

Vascular endothelial growth factor-A (VEGF-A) is an important mediator of angiogenesis in normal and neoplastic tissues. Total VEGF-A levels have been associated with melanoma progression, but the relative contributions of each isoform is unknown. To determine whether differences in the production of any or all of the major VEGF-A isoforms are related to stage of progression, we compared message levels for the three major isoforms of VEGF in melanoma specimens from different stages of progression.Primary melanomas (N = 18), primary recurrences (N = 5), regional dermal metastases (N = 11), nodal metastases (N = 12), normal lymph nodes (N = 18), and distant metastases (N = 9) were prospectively collected. Samples from the horizontal and vertical growth phases of primary tumors were also collected from five additional patients. Message levels for the three major VEGF-A isoforms were measured using real-time quantitative reverse-transcriptase polymerase chain reaction and normalized to beta-actin mRNA levels. There was a marked increase in the expression of all three VEGF-A isoforms from the vertical growth phase tissue as compared with the horizontal growth phase tissue. Primary tumors, local recurrences, regional dermal metastases, nodal metastases, and distant metastases all produced more VEGF(121) and VEGF(165) than negative nodes. Nodal metastases produced the highest level of these two isoforms, higher even than distant metastases. There was no significant difference in VEGF(189) message among the groups. Melanomas in the vertical growth phase produce more VEGF-A (all isoforms) than in the horizontal growth phase. Nodal metastases produce the highest levels of VEGF(121) and VEGF(165), but not VEGF(189) as compared with other stages of progression. These data suggest that the soluble forms of VEGF-A might be an important factor in melanoma metastasis to regional lymph nodes.

Control of vascular cell differentiation by homeobox transcription factors

Homeobox genes are a family of transcription factors with a highly conserved DNA-binding domain that regulate cell proliferation, differentiation, and migration in many cell types in diverse organisms. These properties are responsible for their critical roles in regulating pattern formation and organogenesis during embryogenesis. The cardiovascular system undergoes extensive remodeling during embryogenesis, and cardiovascular remodeling in the adult is associated with normal physiologic processes such as wound healing and the menstrual cycle, and disease states such as atherosclerosis, tumor-induced angiogenesis, and lymphedema. Aside from their roles in the formation of the embryonic vascular system, homeobox genes recently have been implicated in both physiologic and pathologic processes involving vascular remodeling in the adult, such as arterial restenosis after balloon angioplasty, physiologic and tumor-induced angiogenesis, and lymphangiogenesis. Understanding how homeobox genes regulate the phenotype of smooth muscle and endothelium in the vasculature will improve insight into the molecular mechanisms behind vascular cell differentiation and may suggest therapeutic interventions in human disease.

Inhibition of endothelial cell activation by the homeobox gene Gax

BACKGROUND

cardiovascular system, strongly inhibits growth factor-stimulated phenotypic modulation of vascular smooth muscle cells in vitro and in vivo. The function of Gax in vascular endothelium is unknown, but we hypothesized that it may play a similar role there. We therefore studied Gax expression in vascular endothelial cells and its effects on proliferation and tube formation.

MATERIALS AND METHODS

Gax expression in normal endothelial cells was examined in vitro by Northern blot and reverse transcriptase polymerase chain reaction and in vivo by immunohistochemistry. A replication-deficient adenovirus was then used to express Gax in human umbilical vein endothelial cells (HUVECs). HUVEC proliferation, 3H-thymidine uptake, p21 expression, and tube formation on reconstituted basement membrane were measured at different viral multiplicities of infection.

RESULTS

Gax mRNA was detected in HUVECs by reverse transcriptase polymerase chain reaction and Northern blot analysis and in normal vascular endothelium by immunohistochemistry. Compared with controls transduced with a virus expressing beta-galactosidase, Gax strongly inhibited HUVEC proliferation and mitogen-stimulated 3H-thymidine uptake. p21 expression in HUVECs transduced with Gax was increased up to 5-fold as measured by Northern blot, and p21 promoter activity was activated by 4- to 5-fold. Tube formation on Matrigel was strongly inhibited by Gax expression.

CONCLUSIONS

Gax is expressed in vascular endothelium and strongly inhibits endothelial cell activation in response to growth factors and tube formation in vitro. These observations suggest that Gax inhibits endothelial cell transition to the angiogenic phenotype in response to proangiogenic growth factors and, as a negative regulator of angiogenesis, may represent a target for the antiangiogenic therapy of cancer.

Prolonged treatment with angiostatin reduces metastatic burden during radiation therapy

Ionizing radiation (IR) and concomitant angiostatin (AS) produce greater than additive local antitumor effects. We examined whether prolonged AS treatment added to IR reduces proliferation of lung metastases from LLC primary tumors. Flank tumors were treated with 40 Gy with or without AS (25 mg/kg/day). IR plus a 14-day course of AS improved local tumor control and blocked the increase in lung weights observed in the group receiving IR plus a 2-day course of AS group. Animals treated with prolonged AS exhibited no increase in lung weight and no macrometastases. These findings suggest that long-term treatment with antiangiogenic compounds may be effective in preventing metastases from IR-treated tumors as well as increasing the local antitumor effects of radiotherapy.

Dual induction of the Epo-Egr-TNF-alpha- plasmid in hypoxic human colon adenocarcinoma produces tumor growth delay

Gene therapy is a modality for the treatment of solid tumors that involves the introduction of a suicide gene into the tumor cells. Genetic radiotherapy involves the placement of a radiation-sensitive promoter upstream from a suicide gene. Because of their irregular vasculature some solid tumors are chronically hypoxic and hence are resistant to conventional treatment with chemotherapy and ionizing radiation (IR). The purpose of this study was to demonstrate that regional tumor hypoxia could be exploited to improve local tumor control. The cDNA coding the erythropoietin hypoxia-responsive element (EPO) was placed upstream from the Egr-TNF-alpha construct. WIDR human colon adenocarcinoma cells were injected into the right hind limb of nude mice and treated with Epo-Egr-TNF-alpha plasmid with or without IR. Tumor volumes were measured by calipers and tumor necrosis factor (TNF)-alpha content of the tumor was determined by enzyme-linked immunosorbent assay. Treatment with the combined regimen of Epo-Egr-TNF-alpha plasmid + IR resulted in significant tumor growth delay. Tumor TNF-alpha content was increased by 30 per cent in the combined treatment group compared with each treatment alone. Regional tumor hypoxia can be exploited successfully to induce tumor growth delay, enhance local control, and enhance the therapeutic ratio.

Dual Induction of the Epo-Egr-TNF-α Plasmid in Hypoxic Human Colon Adenocarcinoma Produces Tumor Growth Delay

Gene therapy is a modality for the treatment of solid tumors that involves the introduction of a suicide gene into the tumor cells. Genetic radiotherapy involves the placement of a radiation-sensitive promoter upstream from a suicide gene. Because of their irregular vasculature some solid tumors are chronically hypoxic and hence are resistant to conventional treatment with chemotherapy and ionizing radiation (IR). The purpose of this study was to demonstrate that regional tumor hypoxia could be exploited to improve local tumor control. The cDNA coding the erythropoietin hypoxia-responsive element (EPO) was placed upstream from the Egr-TNF-α construct. WIDR human colon adenocarcinoma cells were injected into the right hind limb of nude mice and treated with Epo-Egr-TNF-α plasmid with or without IR. Tumor volumes were measured by calipers and tumor necrosis factor (TNF)-α content of the tumor was determined by enzyme-linked immunosorbent assay. Treatment with the combined regimen of Epo-Egr-TNF-α plasmid + IR resulted in significant tumor growth delay. Tumor TNF-α content was increased by 30 per cent in the combined treatment group compared with each treatment alone. Regional tumor hypoxia can be exploited successfully to induce tumor growth delay, enhance local control, and enhance the therapeutic ratio.

The role of homeobox genes in vascular remodeling and angiogenesis

Homeodomain-containing transcription factors are critical in the regulation of cell proliferation, differentiation, and migration, and they play an important role in organogenesis and pattern formation during embryogenesis. There is evidence that some of them are oncogenes or tumor suppressors. The cardiovascular system undergoes extensive remodeling during embryogenesis and disease states such as atherosclerosis and tumor-induced angiogenesis, and homeobox genes may play an important role in regulating these processes. Recently, homeobox genes have been detected in both vascular smooth muscle and endothelial cells, and they are implicated in pathological processes such as arterial restenosis after balloon angioplasty and tumor-induced angiogenesis. The cellular function of some of these genes is beginning to be elucidated. Therefore, we briefly review what is currently known about the involvement of homeobox transcription factors in both physiological and pathological vascular remodeling and angiogenesis.

Blockage of the vascular endothelial growth factor stress response increases the antitumor effects of ionizing radiation

The family of vascular endothelial growth factor (VEGF) proteins include potent and specific mitogens for vascular endothelial cells that function in the lation of angiogenesis Inhibition of VEGF-induced angiogenesis either by neutralizing antibodies or dominant-negative soluble receptor, blocks the growth of primary and metastatic experimental tumors Here we report that VEGF expression is induced in Lewis lung carcinomas (LLCs) both in vitro and vivo after exposure to ionizing radiation (IR) and in human tumor cell lines (Seg-1 esophageal adenocarcinoma, SQ20B squamous cell carcinoma, T98 and U87 glioblastomas, and U1 melanoma) in vitro. The biological significance of IR-induced VEGF production is supported by our finding that treatment of tumor-bearing mice (LLC, Seg-1, SQ20B, and U87) with a neutralizing antibody to VEGF-165 before irradiation is associated with a greater than additive antitumor effect. In vitro, the addition of VEGF decreases IR-induced killing of human umbilical vein endothelial cells, and the anti-VEGF treatment potentiates IR-induced lethality of human umbilical vein endothelial cells. Neither recombinant VEGF protein nor neutralizing antibody to VEGF affects the radiosensitivity of tumor cells These findings support a model in which induction of VEGF by IR contributes to the protection of tumor blood vessels from radiation-mediated cytotoxicity and thereby to tumor radioresistance.

Potentiation of the antitumor effect of ionizing radiation by brief concomitant exposures to angiostatin

Angiostatin, a proteolytic fragment of plasminogen, inhibits the growth of primary and metastatic tumors by suppressing angiogenesis. When used in combination with ionizing radiation (IR), angiostatin demonstrates potent antitumor synergism, largely caused by inhibition of the tumor microvasculature. We report here the temporal interaction of angiostatin and IR in Lewis lung carcinoma (LLC) tumors growing in the hind limbs of syngeneic mice. Tumors with an initial mean volume of 510 +/- 151 mm3 were treated with IR alone (20 Gy x 2 doses on days 0 and 1), angiostatin alone (25 mg/kg/day divided twice daily) on days 0 through 13, or a combination of the two as follows: (a) IR plus angiostatin (days 0 through 13); (b) IR plus angiostatin (days 0 and 1); and (c) IR followed by angiostatin beginning on the day after IR completion and given daily thereafter (days 2 through 13). By day 14, tumors in untreated control mice had grown to 6110 +/- 582 mm3, whereas in mice treated with: (a) IR alone, tumors had grown to 2854 +/- 338 mm3 (P < 0.05 compared with untreated controls); and (b) angiostatin alone, tumors had grown to 3666 +/- 453 mm3 (P < 0.05 compared with untreated controls). In combined-treatment groups, in mice treated with: (a) IR plus longer-course angiostatin, tumors reached 2022 +/- 282 mm3 (P = 0.036 compared with IR alone); (b) IR followed by angiostatin, tumors reached 2677 +/- 469 mm3 (P > 0.05 compared with IR alone); and (c) IR plus short-course angiostatin, tumors reached 1032 +/- 78 mm3 (P < 0.001 compared with IR alone). These findings demonstrate that the efficacy of experimental radiation therapy is potentiated by brief concomitant exposure of the tumor vasculature to angiostatin.

Combined effects of angiostatin and ionizing radiation in antitumour therapy

Angiogenesis, the formation of new capillaries from pre-existing vessels, is essential for tumour progression. Angiostatin, a proteolytic fragment of plasminogen that was first isolated from the serum and urine of tumour-bearing mice, inhibits angiogenesis and thereby growth of primary and metastatic tumours. Radiotherapy is important in the treatment of many human cancers, but is often unsuccessful because of tumour cell radiation resistance. Here we combine radiation with angiostatin to target tumour vasculature that is genetically stable and therefore less likely to develop resistance. The results show an antitumour interaction between ionizing radiation and angiostatin for four distinct tumour types, at doses of radiation that are used in radiotherapy. The combination produced no increase in toxicity towards normal tissue. In vitro studies show that radiation and angiostatin have combined cytotoxic effects on endothelial cells, but not tumour cells. In vivo studies show that these agents, in combination, target the tumour vasculature. Our results provide support for combining ionizing radiation with angiostatin to improve tumour eradication without increasing deleterious effects.

p21CIP1-mediated inhibition of cell proliferation by overexpression of the gax homeodomain gene

gax, a diverged homeobox gene expressed in vascular smooth muscle cells (VSMCs), is down-regulated in vitro by mitogen stimulation and in vivo in response to vascular injury that leads to cellular proliferation. Recombinant Gax protein microinjected into VSMCs and fibroblasts inhibited the mitogen-induced entry into S-phase when introduced either during quiescence or early stages of G1. Overexpression of gax with a replication-defective adenovirus vector resulted in G0/G1 cell cycle arrest of VSMCs and fibroblasts. The gax-induced growth inhibition correlated with a p53-independent up-regulation of the cyclin-dependent kinase inhibitor p21. Gax overexpression also led to an association of p21 with cdk2 complexes and a decrease in cdk2 activity. Fibroblasts deficient in p21 were not susceptible to a reduction in cdk2 activity or growth inhibition by gax overexpression. Localized delivery of the virus to denuded rat carotid arteries significantly reduced neointima formation and luminal narrowing. These data indicate that gax overexpression can inhibit cell proliferation in a p21-dependent manner and can modulate injury-induced changes in vessel wall morphology that result from excessive cellular proliferation.