Abstract P2-07-09: Integrative analysis of miRNA and mRNA expression in metastatic versus non-metastatic triple negative breast cancer

Background: Triple Negative Breast Cancer (TNBC) is a subset of breast cancer that is difficult to treat clinically and is characterized by being estrogen receptor (ER) negative, progesterone receptor (PR) negative, and does not overexpress human epidermal growth factor receptor 2 (HER2). Patients with TNBC tend to have a worse prognosis than other breast cancer subtypes.

Methods: We obtained fifteen TNBC sample FFPE tissue blocks with corresponding plasma samples. All samples were from primary tumors; seven samples having metastasized, four samples that had not metastasized and four samples with unknown metastatic status. The total RNA was isolated from FFPE blocks using the RecoverAll Total Nucleic Acid Isolation Protocol. miRNA from plasma was isolated using Ambion's mirVANA kit. The plasma and tissue miRNAs were evaluated using the QuantStudio qPCR platform, capturing ˜750 miRNAs. The mRNA was processed using the TruSeq RNA Access kit and sequenced on the Illumina NextSeq platform. Analysis of the miRNA and mRNA individually was performed using limma and DESeq2 packages, respectively. Gene enrichment analysis of the mRNA expression was done using the GAGE package on KEGG pathways while the integrative analysis was done with sparse Canonical Correlation Analysis (sCCA) using the PMA pacakge.

Results: Analysis of plasma miRNA had four miRNAs with a significant difference in raw p-value (p < 0.05) between metastatic and non-metastatic TNBC; miRNA 708, 483-3p, 518f, and 766; in the tissue there were fifteen miRNA with p < 0.05, with one miR-872 still having significance after adjusting for multiple testing. mRNA had 33 genes being significant after multiple testing correction with several immune KEGG pathways being downregulated in metastatic samples (adjusted p < 0.05). The integrative analysis revealed five microRNA (miR-216, miR-127, miR-370, miR-382, and miR-487b) and 312 gene modules enriched in integrin (Fisher p < 10^-5) and extracellular matrix (Fisher p < 10^-6) signaling.

Conclusions: One of the circulating plasma miRNAs, miR483-3p, has been found to promote tumorigenesis, while miR581f and miR766 have not been reported in cancer to date. Further investigation into these miRNA could provide a feasible biomarker. The downregulation of immune pathways observed within the metastatic TNBC subjects implies immune evasion is of particular importance for metastasis and a targeted immunotherapy may be a viable treatment option. The integrative analysis of the miRNA and mRNA showed an enrichment in pathways previously linked to increased proliferation and chemoresistance, with an increased signal compared to either miRNA or mRNA alone.

Citation Format: Shih AJ, Korsunsky I, Guttadauria B, Bhuiya T, Liew A, Khalili H, Gregersen PK, Lee AT. Integrative analysis of miRNA and mRNA expression in metastatic versus non-metastatic triple negative 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 P2-07-09.

P4: CIRCULATING MIRNA PROFILES POINT TO DYSREGULATION IN TGFBETA/SMAD3 TUMOR SUPPRESSOR SIGNATURE IN BRCA POSITIVE BREAST CANCER PATIENTS

Purpose of Study

Over 240,000 individuals are diagnosed with breast cancer (BrCa) of which 12,000 individuals carry BRCA germline mutations. MicroRNA dysregulation is common in malignancy and may correlate with germline mutations.

Aims:

1. Analyze microRNAs in patients with breast cancer with or without BRCA germ line mutations, with and without cancer.

2. Identify molecular BRCA mutant patients to deduct reasons for accelerated malignancy.

Methods Used

We analyzed plasma miR expression from 94 br cancer patients (41 BRCA positive) relative to 24 normal controls. All samples were collected between 2010 and 2014 and survival data was known for all cancer patients. TaqMan Open Array panel was used to simultaneously run hundreds of microRNA assays in the Applied Biosystem Open array real time PCR. Using AB open array real time PCR, 756 miRNA species were detected. Two-sample t-test was used for all 2-sample comparison and ANOVA followed by Tukey HSD post-hoc test to compare the miRs mean differences. All tests were 2-tailed and results with a p<0.05 were considered statistically significant.

Summary of Results

BRCA+underexpressed hsa-mir-10a and hsa-mir-376c and over-expressed Hsa- mir- 326 and Hsa-mir-143 relative to BRCA-; p<0.05.

Using Coremine data mining linking genes and diseases differentially expressed circulating miRs are linked to tumor suppressor TGFbeta/SMAD3.

Conclusions

The early onset of breast cancer in BRCA mutant patients may recapitulate the pro-oncogenic effects of TGF-β. The context dependent SMAD3 binding & tumor suppression TGF-β effects are abrogated in BRCA mutant patients. TGF-β/Smad3 tumor-suppressor signature suppresses local inflammation in the tumor microenvironment.

Scrape cytology of meningioangiomatosis: a report of two cases with diagnostic cytologic features

BACKGROUND

Meningioangiomatosis is a rare, probably hamartomatous condition characterized by nonneoplastic intracortical proliferation of meningothelial cells, capillaries and fibroblasts. The lesion may mimic a tumor both clinically and radiologically. We present two cases of the entity, including its cytologic features.

CASES

A 71-year-old man presented with an eight-month history of headache, change in vision, loss of depth perception and unsteady gait. Magnetic resonance imaging (MRI) revealed an infiltrative lesion of the left occipital lobe, diffuse in nature. Cytologic smears prepared at the time of intraoperative consultation showed numerous thin-walled capillaries together with bland spindle cells. Occasional large cells with prominent nucleoli were also present. Frozen section confirmed the presence of linear, small capillaries surrounded by fibroblasts and meningothelial cells, consistent with meningioangiomatosis. The second case was a 3-year-old girl who presented with a one-day history of seizure, vomiting, fever and perioral cyanosis. MRI revealed an enhancing lesion in a temporal lobe of the cerebrum. The patient underwent excision of the lesion. Intraoperative cytology showed numerous meningothelial whorls together with neurons and occasional capillaries. Both patients were well, one after three months and the other after six.

CONCLUSION

Meningioangiomatosis is a lesion characterized by linear capillaries, meningothelial cells and neurons, some exhibiting nuclear atypia. The combination can lead to an erroneous diagnosis of more common conditions, such as meningioma (with intracortical extension) and anaplastic astrocytoma. Contrary to these more sinister diagnoses, meningioangiomatosis is a completely benign, presumably hamartomatous entity.

Primary synovial sarcoma of the kidney: a case report with literature review

We describe a case of primary renal synovial sarcoma (SS) in a 48-year-old man. The patient presented with hematuria and was found to have a large tumor in his left kidney on computed tomography scan. Histology revealed a highly cellular spindle cell neoplasm with minimal pleomorphism. The major differential diagnoses included leiomyosarcoma, hemangiopericytoma, and SS. The presence of focal areas with a biphasic pattern, uniformly positive immunostain for bcl-2, focally positive immunostains for epithelial membrane antigen and cytokeratin, and negative immunostains for CD-34, smooth muscle actin and S-100 established the diagnosis. This was subsequently confirmed by molecular testing for t(X;18) translocation. Since the existence of primary SS in the kidney was first suggested in 1999, to the best of our knowledge a total of 19 cases including the present case have been reported to date. Although primary renal SS is rare, these findings indicate that it should be included in the differential diagnosis of spindle cell tumors of the kidney.

Polymorphous low-grade adenocarcinoma: flow cytometric, p53, and PCNA analysis

Polymorphous low-grade adenocarcinoma of minor salivary glands (terminal duct carcinoma, lobular carcinoma) was first defined more than a decade ago. A 17% recurrence rate and a 9% metastasis rate have been reported. Fifteen formalin-fixed, paraffin-embedded archival cases were analyzed. Ploidy and proliferative activity were evaluated with flow cytometric analysis. Demonstration of an abnormal p53 gene product and proliferative cell nuclear antigen analyses were also performed with routine immunohistochemical procedures. The purpose of this investigation was to evaluate these parameters and determine if a correlation existed. Flow cytometry was performed on 10 cases; 3 showed an aneuploid cell line (mean, S-phase diploid tumor cells 5.9%; S-phase aneuploid 26.7%). Products of a mutation of the p53 tumor suppressor gene have been noted to accumulate in salivary gland tumors, both benign and malignant. Qualitative assessment revealed p53 positive staining in 4 of 15 tumors; positive cells comprised 5% to 10% of the tumor. The percentage of tumor cells positive for proliferative cell nuclear antigen staining ranged from 0.5% to 70%. There was no correlation between proliferative activity as determined by proliferative cell nuclear antigen when compared with results of flow cytometric analysis except for one case that exhibited p53 staining, a 26% proliferative cell nuclear antigen fraction, and a distinct aneuploid cell line.

Correlation of proliferative index (PCNA reactivity and Ki-67 reactivity) in primary breast carcinoma with hormone status, lymph node status, and disease-free survival

The proliferative activity in 42 cases of breast cancer were assessed immunohistochemically using antibodies to proliferating cell nuclear antigen (PCNA) and Ki-67. These indices were correlated with the steroid receptor status, pathologic stage, and disease-free survival. There was a strong direct correlation between the two proliferation indices (r = .902, P < 0.001, Kendall's rank correlation). There was a weak correlation between the hormone receptor status and proliferation indices that was not significant when statistically tested. The cases were stratified into PCNA low proliferative index (PI) group (< 4.5% positive cells) and PCNA high PI group (> 4.5% positive cells). In the low PI group, five of 18 (28%) patients were node-positive in contrast to eight of 14 (58%) patients in the high PI group. After a follow-up period of 42-60 months, 14 of 19 (74%) patients in the low PI group were disease-free compared to 10 of 17 (53%) patients in the high PI group. The PCNA and Ki-67 proliferative indices appear to be of great prognostic value and may help identify a subset of breast cancer patients who should be given adjuvant therapy.

Primary salivary gland amyloidosis causing sicca syndrome

Sicca syndrome (SS), consisting of xerostomia and xerophthalmia, may be caused by various disease processes. We present a unique case of SS secondary to primary amyloidosis. Amyloidosis is a rare but definite cause of SS and should be included in the differential diagnosis of any patient who presents with sicca symptoms. A literature review comparing amyloidotic patients with SS and patients with amyloidosis only demonstrates that both of these groups of patients present similarly with regard to symptoms. However, the majority of patients with SS present with sicca symptoms initially in addition to symptoms of amyloidosis. These SS patients also present with proteinuria and negative serology test results. Therefore, patients presenting with sicca symptoms, proteinuria, and negative serologic findings should be suspect for amyloidosis. The importance of distinguishing the diagnosis of Sjögren's syndrome from SS in these patients cannot be overemphasized. There is a significantly higher incidence of developing a lymphoma in Sjögren's syndrome patients. This has important implications for the head and neck surgeon treating these patients.