Ady Yosepovich

MicroRNAs accurately identify cancer tissue origin

MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that is involved in oncogenesis and shows remarkable tissue specificity. Their potential for tumor classification suggests they may be used in identifying the tissue in which cancers of unknown primary origin arose, a major clinical problem. We measured miRNA expression levels in 400 paraffin-embedded and fresh-frozen samples from 22 different tumor tissues and metastases. We used miRNA microarray data of 253 samples to construct a transparent classifier based on 48 miRNAs. Two-thirds of samples were classified with high confidence, with accuracy >90%. In an independent blinded test-set of 83 samples, overall high-confidence accuracy reached 89%. Classification accuracy reached 100% for most tissue classes, including 131 metastatic samples. We further validated the utility of the miRNA biomarkers by quantitative RT-PCR using 65 additional blinded test samples. Our findings demonstrate the effectiveness of miRNAs as biomarkers for tracing the tissue of origin of cancers of unknown primary origin.

Timing of sentinel lymph node biopsy in patients receiving neoadjuvant chemotherapy for breast cancer.

To address optimal timing of sentinel lymph node biopsy (SLNB) in breast cancer patients undergoing neoadjuvant treatment.

Real-time Imaging of Lymphogenic Metastasis in Orthotopic Human Breast Cancer

Metastatic spread to regional lymph nodes is one of the earliest events of tumor cell dissemination and presents a most significant prognostic factor for predicting survival of cancer patients. Real-time in vivo imaging of the spread of tumor cells through the lymphatic system can enhance our understanding of the metastatic process. Herein, we describe the use of in vivo fluorescence microscopy imaging to monitor the progression of lymph node metastasis as well as the course of spontaneous metastasis through the lymphatic system of orthotopic MDA-MB-231 human breast cancer tumors in severe combined immunodeficient mice. High-resolution noninvasive visualization of metastasizing cancer cells in the inguinal lymph nodes was achieved using cells expressing high levels of red fluorescent protein. Sequential imaging of these lymph nodes revealed the initial invasion of the tumor cells through the lymphatic system into the subcapsular sinuses followed by intrusion into the parenchyma of the nodes. FITC-dextran injected i.d. in the tumor area enabled simultaneous tracking of lymphatic vessels, labeled in green, and disseminated red cancer cells within these vessels. Fast snapshots of spontaneously metastasizing cells in the lymphatic vessels monitored the movement of a few tumor cells and the development of clumps clustered at lymphatic vessel junctions. Quantification of high interstitial fluid pressure (IFP) in the tumors and fast drainage rates of the FITC-dextran into the peritumoral lymphatic vessels suggested an IFP-induced intravasation into the lymphatic system. This work presents unprecedented live fluorescence images that may help to clarify the steps occurring in the course of spontaneous lymphogenic metastasis.

Cancer cells suppress p53 in adjacent fibroblasts

The p53 tumor suppressor serves as a crucial barrier against cancer development. In tumor cells and their progenitors, p53 suppresses cancer in a cell-autonomous manner. However, p53 also possesses non-cell-autonomous activities. For example, p53 of stromal fibroblasts can modulate the spectrum of proteins secreted by these cells, rendering their microenvironment less supportive of the survival and spread of adjacent tumor cells. We now report that epithelial tumor cells can suppress p53 induction in neighboring fibroblasts, an effect reproducible by tumor cell-conditioned medium. The ability to suppress fibroblast p53 activation is acquired by epithelial cells in the course of neoplastic transformation. Specifically, stable transduction of immortalized epithelial cells by mutant H-Ras and p53-specific short inhibitory RNA endows them with the ability to quench fibroblast p53 induction. Importantly, human cancer-associated fibroblasts are more susceptible to this suppression than normal fibroblasts. These findings underscore a mechanism whereby epithelial cancer cells may overcome the non-cell-autonomous tumor suppressor function of p53 in stromal fibroblasts.

Zinc supplementation augments in vivo antitumor effect of chemotherapy by restoring p53 function

Activated p53 is necessary for tumor suppression. Homeodomain‐interacting protein kinase‐2 (HIPK2) is a positive regulator of functional p53. HIPK2 modulates wild‐type p53 activity toward proapoptotic transcription and tumor suppression by the phosphorylation of serine 46. Knock‐down of HIPK2 interferes with tumor suppression and sensitivity to chemotherapy. Combined administration of adriamycin and zinc restores activity of misfolded p53 and enables the induction of its proapoptotic and tumor suppressor functions in vitro and in vivo. We therefore looked for a cancer model where HIPK2 expression is low. MMTV‐neu transgenic mice overexpressing HER2/neu, develop mammary tumors at puberty with a long latency, showing very low expression of HIPK2. Here we show that whereas these tumors are resistant to adriamycin treatment, a combination of adriamycin and zinc suppresses tumor growth in vivo in these mice, an effect evidenced by the histological features of the mammary tumors. The combined treatment of adriamycin and zinc also restores wild‐type p53 conformation and induces proapoptotic transcription activity. These findings may open up new possibilities for the treatment of human cancers via the combination of zinc with chemotherapeutic agents, for a selected group of patients expressing low levels of HIPK2, with an intact p53. In addition, HIPK2 may serve as a new biomarker for tumor aggressiveness.

Primary Malignancies of the Heart and Pericardium

Primary malignancies of the heart and pericardium are rare. All the available data come from autopsy studies, case reports, and, in recent years, from large, specialized, single‐center studies. Nevertheless, if primary malignancy is present, it may have a devastating implication for patients. Malignancies may affect heart function, also causing left‐sided or right‐sided heart failure. In addition, they can be responsible for embolic events or arrhythmias. Today, with the widespread use of noninvasive imaging modalities, heart tumors become evident, even as an incidental finding. A multimodality imaging approach is usually required to establish the final diagnosis. Despite the increased awareness and improved diagnostic techniques, clinical manifestations of primary malignancy of the heart and pericardium are so variable that their occurrence may still come as a surprise during surgery or autopsy. No randomized clinical trials have been carried out to determine the optimal therapy for these primary malignancies. Surgery is performed for small tumors. Chemotherapy and radiation therapy can be of help. Partial resection of large neoplasms is performed to relieve mechanical effects, such as cardiac compression or hemodynamic obstruction. Most patients present with marginally resectable or technically nonresectable disease at the time of diagnosis. It seems that orthotopic cardiac transplantation with subsequent immunosuppressive therapy may represent an option for very carefully selected patients. Early diagnosis and radical exeresis are of great importance for long‐term survival of a primary cardiac malignancy. This can rarely be accomplished, and overall results are very disappointing.

High efficacy of pre-operative trastuzumab combined with paclitaxel following doxorubicin & cyclophosphamide in operable breast cancer

Background. Trastuzumab in combination with adjuvant chemotherapy improves disease free survival and overall survival in HER2 over-expressing breast cancer patients. Data concerning the use of trastuzumab in the neo-adjuvant setting is limited. We aimed to compare outcome of HER2 over-expressing breast cancer patients treated with either standard chemotherapy, consisting of doxorubicin, cyclophosphamide and a taxane to outcome of patients treated with the same chemotherapy regimen with the addition of trastuzumab in concurrence with paclitaxel. Methods. We conducted a retrospective review of all consecutive HER2 over-expressing breast cancer patients treated at the participating institutions during the study period and received neo-adjuvant therapy. Allocation to trastuzumab was not based on clinical parameters and was approved only by part of the insurers. Clinical and pathological characteristics, as well as response rate and type of surgery were analyzed. Results. Thirty seven patients received chemotherapy alone and 24 patients received chemotherapy and trastuzumab. A similar distribution of age, clinical stage and histology was noted in both groups. The rate of pathological complete response (pCR) was significantly higher among the trastuzumab-treated group compared to chemotherapy-alone group (75 vs. 24% respectively, p=0.0002). pCR in the breast was noted in 18 of 24 (75%) compared to 10 of 36 (28%, p=0.0005) and pCR in the axillary lymph nodes was noted in 19 of 20 (95%) compared to 8 of 28 (29%, p=0.0001), in the trastuzumab group compared to the chemotherapy-alone group respectively. The safety profile was similar between both groups and no clinical cardiotoxicity were noted. Conclusions. The addition of trastuzumab to standard chemotherapy in the neo-adjuvant setting improves pathological complete response rates in HER2 over-expressing breast cancer patients.

Chronic cholecystitis with bone metaplasia. A case report.

Bone metaplasia is a rare phenomenon in the gastrointestinal tract. We present a case of a 58-year-old man who underwent laparoscopic cholecystectomy for symptoms of chronic cholecystitis. Histologic examination of the removed gallbladder revealed intramural bone metaplasia in association with chronic cholecystitis. To the best of our knowledge, such a case has not yet been reported. The clinical significance of this finding remains to be elucidated.

Freehand Elastography for Determination of Breast Cancer Size Comparison With B-Mode Sonography and Histopathologic Measurement

Elastography assesses the strain of soft tissues and is used to enhance diagnostic accuracy in evaluating breast tumors, but minimal data exist on its ability to accurately assess tumor size. This study was performed to assess the preoperative accuracy of measuring the size of biopsyproven breast cancer lesions with elastography and conventional B‐mode sonography compared with the reference standard size measured by histopathologic examination.

Hormone receptor expression is associated with a unique pattern of metastatic spread and increased survival among HER2-overexpressing breast cancer patients.

Objectives:HER2/neu (HER2) overexpression occurs in approximately 20% of breast cancers and is associated with aggressive disease. Although a significant number of HER2-positive tumors also express hormone receptors (HR), the effects HR expression has on clinical characteristics, including response to trastuzumab among HER2-positive breast cancer, has not been elucidated yet. Methods:A retrospective analysis of consecutive metastatic HER2-positive breast cancer patients was conducted in 2 medical centers. Associations between hormone receptors expression and clinical variables, and metastatic spread pattern and survival were studied. Results:The study population included 137 metastatic HER2-positive breast cancer patients, 56 of them were HR-positive and 81 were HR-negative. No significant differences between the 2 groups were found for demographic and clinical characteristics, including age, stage at diagnosis, tumor histology, and grade. Similar response rate to trastuzumab was observed in both study groups. Significantly, longer, median, disease-free, and overall survival was noted among the HR-positive patients. Patients in the HR-negative group had significantly more liver metastases, a trend for more brain metastases, and less bone metastases. There was a strong trend for more visceral metastases in the HR-negative group. Conclusions:Our results suggest an important role for HR expression in modulating metastases predilection and disease progression in HER2-positive breast cancer.