Identification of MGB1 as a marker in the differential diagnosis of lung tumors in patients with a history of breast cancer by analysis of publicly available SAGE data

Anti-hMAM monoclonal antibodies evaluated in breast and non-breast tissues for differential diagnosis implication

PURPOSE

Human mammaglobin (hMAM) is a breast tissue-specific marker that may have potency for the diagnosis of breast cancer. However, there is a lack of commercialization of anti-hMAM antibody made in China.

METHODS

Immunoreactivities of 2 self-made monoclonal anti-hMAM antibodies, MEF521 and MDA822, were evaluated by immunohistochemistry staining and compared with imported monoclonal antibody ab81611. A total of 48 cases of primary breast cancers, 36 cases of benign or normal breast tissues, 52 cases of lymph nodes or organ metastases from breast cancer, and 90 cases of non-breast primary carcinoma tissues were analyzed.

RESULTS

All 3 anti-hMAM antibodies showed high positive expression of hMAM in primary breast cancers, benign, and normal breast tissues. The positive ratio for MEF521 (33.3%) or MDA822 (44.4%) was much higher than that of ab81611 (16.7%) in lymph node metastasis from breast cancer (p = 0.038). There was no correlation between hMAM expression and clinicopathologic features of breast cancer in the 3 groups of antibodies. In 90 cases of non-breast primary carcinoma tissues, no hMAM-positive ones were observed in the MEF521 or MDA822 group, but 48 (53.3%) in the ab81611 group were positive, indicating that breast tissue specificity of the 2 self-made anti-hMAM monoclonal antibodies much higher than that of ab81611 (p<0.001).

CONCLUSIONS

Our results showed that MDA822 and MEF521 are more specific to breast cancer as measured by means of immunohistochemistry. Therefore, the 2 self-made anti-hMAM antibodies may have good prospects for clinical application in the differential diagnosis of breast tumor and breast cancer metastases.

Upregulation of human mammaglobin reduces migration and invasion of breast cancer cells

Little is known about the biological role of human mammaglobin (hMAM) that is considered as a promising marker for breast cancer. Here, we investigated hMAM's role related to migration and invasion of human breast cancer cells (hBCC). Compared to normal cells, hBCC have high MAM mRNA expression levels. Of the hBCC tested, MAM mRNA expression levels were higher in noninvasive than in invasive cells. Overexpression of hMAM in breast cancer cells decreased migration and invasion, whereas knockdown of hMAM increased both. Taken together, these results suggest that metastasis of hBCC could be controlled by hMAM expression levels.

Malignant cells are not found in ovarian cortex from breast cancer patients undergoing ovarian cortex cryopreservation

BACKGROUND

Breast cancer is a frequent indication for ovarian cortex cryopreservation due to its high incidence. The main concern of this procedure is the possibility of reintroducing metastatic cells within the implant, an issue that has not been addressed systematically. Thus, a study was designed to analyse the presence of ovarian metastases in breast cancer patients undergoing ovarian tissue cryopreservation.

METHODS

Morphological and immunohistochemical studies following the concept of the sentinel lymph node (SLN) were performed on 100 cortical ovarian biopsies obtained from 63 patients and on six frozen-thawed entire cortex from patients with the diagnosis of infiltrating ductal breast carcinoma undergoing ovarian cortex extraction and cryopreservation. The antibody panel included Cytokeratin CAM 5.2, Gross Cystic Disease Fluid Protein-15 (GCDFP15), Wilms' tumour antigen-1 (WT1) and Mammaglobin 1.

RESULTS

Employing only morphologic criteria, suspicious neoplastic cells were detected in five biopsies, but in none of the six entire cortex analysed. These five cases were reclassified as hyperplasic surface epithelium-inclusion cysts (CAM 5.2+, WT1+) or apoptotic granulosa cells (CAM 5.2-, GCDFP15+, WT1-).

CONCLUSIONS

Using the methodology of the SLN our data suggest the absence of tumour cells in biopsies obtained from patients undergoing ovarian cortex cryopreservation to preserve their fertility potential, although future methods of cancer screening may change our perception of this procedure.

Inactivation of LLC1 gene in nonsmall cell lung cancer

Serial analysis of gene expression studies led us to identify a previously unknown gene, c20orf85, that is present in the normal lung epithelium but absent or downregulated in most primary nonsmall cell lung cancers and lung cancer cell lines. We named this gene LLC1 for Low in Lung Cancer 1. LLC1 is located on chromosome 20q13.3 and has a 70% GC content in the promoter region. It has 4 exons and encodes a protein containing 137 amino acids. By in situ hybridization, we observed that LLC1 message is localized in normal lung bronchial epithelial cells but absent in 13 of 14 lung adenocarcinoma and 9 out of 10 lung squamous carcinoma samples. Methylation at CpG sites of the LLC1 promoter was frequently observed in lung cancer cell lines and in a fraction of primary lung cancer tissues. Treatment with 5-aza deoxycytidine resulted in a reduced methylation of the LLC1 promoter concomitant with the increase of LLC1 expression. These results suggest that inactivation of LLC1 by means of promoter methylation is a frequent event in nonsmall cell lung cancer and may play a role in lung tumorigenesis.

Breast-specific expression of MGB1/mammaglobin: an examination of 480 tumors from various organs and clinicopathological analysis of MGB1-positive breast cancers

Previously, we used the reverse transcription-polymerase chain reaction (RT-PCR) to show that mammaglobin (MGB1) can serve as a differential marker of breast cancer metastasis from primary lung cancer. However, mRNA-based methods are not appropriate for use in clinical practices. In this study, we examined MGB1 protein expression in 480 tumors from various organs using immunohistochemical detection and a tissue microarray technique. Breast cancers expressing MGB1 were also analyzed clinicopathologically to determine whether these cancers constitute a characteristic subset. Immunohistochemically, MGB1 was expressed specifically in breast cancers. Of the other cancers examined, including 29 of the head and neck, eight of the thyroid, 106 of the lung, 35 of the gastrointestinal tract, three of the pancreas, 14 of the uterine cervix and 13 of the ovary, none were positive for MGB1 except a proportion of salivary gland tumors (6/11, 55%) and endometrial cancers (3/23, 13%). Among the 238 breast cancers, MGB1 was expressed in 114 (48%), most of which were classified histologically as invasive duct or lobular carcinomas. Clinicopathologically, MGB1 expression was associated with positive expression of estrogen receptors and negative expression of CK5, but not with pathological stage, HER2 gene amplification or p53 immunoreactivity. Kaplan-Meier analysis revealed prolonged disease-free survival in patients with MGB1-positive breast cancers (log rank test, P=0.016), but the Cox proportional hazard model failed to confirm that MGB1 was an independent prognostic factor (hazard ratio 1.77, P=0.1755). In terms of practical diagnosis, MGB1 immunohistochemistry can serve as a differential marker of breast cancer metastasis from primary lung cancer for two reasons. Firstly, HER2-positive breast cancer frequently lacks estrogen receptor expression, but MGB1 is expressed in about half of this subtype. Secondly, as primary lung adenocarcinomas may express estrogen receptors, MGB1 expression provides further discrimination of the origin of breast cancers.

Expression analysis of mammaglobin A (SCGB2A2) and lipophilin B (SCGB1D2) in more than 300 human tumors and matching normal tissues reveals their co-expression in gynecologic malignancies

Background

Mammaglobin A (SCGB2A2) and lipophilin B (SCGB1D2), two members of the secretoglobin superfamily, are known to be co-expressed in breast cancer, where their proteins form a covalent complex. Based on the relatively high tissue-specific expression pattern, it has been proposed that the mammaglobin A protein and/or its complex with lipophilin B could be used in breast cancer diagnosis and treatment. In view of these clinical implications, the aim of the present study was to analyze the expression of both genes in a large panel of human solid tumors (n = 309), corresponding normal tissues (n = 309) and cell lines (n = 11), in order to evaluate their tissue specific expression and co-expression pattern.

Methods

For gene and protein expression analyses, northern blot, dot blot hybridization of matched tumor/normal arrays (cancer profiling arrays), quantitative RT-PCR, non-radioisotopic RNA in situ hybridization and immunohistochemistry were used.

Results

Cancer profiling array data demonstrated that mammaglobin A and lipophilin B expression is not restricted to normal and malignant breast tissue. Both genes were abundantly expressed in tumors of the female genital tract, i.e. endometrial, ovarian and cervical cancer. In these four tissues the expression pattern of mammaglobin A and lipophilin B was highly concordant, with both genes being down-, up- or not regulated in the same tissue samples. In breast tissue, mammaglobin A expression was down-regulated in 49% and up-regulated in 12% of breast tumor specimens compared with matching normal tissues, while lipophilin B was down-regulated in 59% and up-regulated in 3% of cases. In endometrial tissue, expression of mammaglobin A and lipophilin B was clearly up-regulated in tumors (47% and 49% respectively). Both genes exhibited down-regulation in 22% of endometrial tumors. The only exceptions to this concordance of mammaglobin A/lipophilin B expression were normal and malignant tissues of prostate and kidney, where only lipophilin B was abundantly expressed and mammaglobin A was entirely absent. RNA in situ hybridization and immunohistochemistry confirmed expression of mammaglobin A on a cellular level in endometrial and cervical cancer and their corresponding normal tissues.

Conclusion

Altogether, these data suggest that expression of mammaglobin A and lipophilin B might be controlled in different tissues by the same regulatory transcriptional mechanisms. Diagnostic assays based on mammaglobin A expression and/or the mammaglobin A/lipophilin B complex appear to be less specific for breast cancer, but with a broader spectrum of potential applications, which includes gynecologic malignancies.

Human Small Breast Epithelial Mucin: The Promise of a New Breast Tumor Biomarker

Breast cancer remains one of the most frequently diagnosed cancers today. In developed countries, one in eight women is expected to present with breast cancer within her lifetime and an estimated 1,000,000 cases are detected each year worldwide (Canadian Cancer Statistics, http://www.cancer.ca/vgn/images/ portal/cit_86751114/14/33/1959864 11niw_stats2004_en.pdf). For women with recurrent disease, the median time of survival is about 2 years. Despite optimal surgery, adjuvant irradiation, hormonal treatment, and chemotherapy, approximately 30% of patients with localized breast cancer finally develop distant metastases. Early detection, which enables intervention at a localized and potentially curable stage, remains a central goal in breast cancer treatment. Indeed, the 5-year survival rate for women with breast cancer has been shown to increase dramatically when the disease is diagnosed at an early stage: from less than 25% in women with disseminated cancer to about 75% in patients with regional disease and over 95% in women with a localized tumor (Breast Cancer Facts and Figures, 2001-2002, http://www.cancer.org/downloads/STT/BrCaFF 2001.pdf). Unfortunately, only 60% of all breast cancers are diagnosed at a local stage. Any improvement in early detection through identification of tumor biomarkers would have a significant impact on reducing overall breast cancer mortality.