Expression of tight junction molecules in breast carcinomas analysed by array PCR and immunohistochemistry.

In the past few decades an enormous amount of data became known to clarify the molecular composition and architecture of tight junctions (TJs). Despite the efforts, the expression and function of several TJ genes and proteins in breast carcinoma are still not known and some of the data are contradictory. The expression of forty-four TJ associated genes was examined at mRNA level in eighteen invasive ductal breast carcinoma samples and corresponding normal breast tissues by using low density array PCR. Expressions of claudins (CLDNs) 5, 10, 16, 17, and 18, and ZO-1, ZO-2 were evaluated by immunohistochemistry as well. Using immunohistochemical phenotype as a surrogate for the genetic subtype, 11 luminal A, 3 luminal B, 3 triple negative and one HER2+ cases were included. Ten genes were significantly downregulated in tumors compared with normal breast tissues (CLDNs 5, 10, 16, 18, 19, CTNNAL1, JAM-B, ZO-1, ZO-2 and PARD3), whereas one gene (CLDN17) was significantly up-regulated in tumors when compared with normal breast. At protein level CLDNs 5, 10, 16, 18, ZO-1 and ZO-2 were downregulated in tumors as compared with normal breast tissue. CLDN17 showed variable expression in tumor tissues in comparison to normal breast. In the single HER2+ tumor when compared with the other subtypes CLDNs 5, 16, 17, 18, CTNNAL1, JAM-B, ZO-1, ZO-2 and PARD3 genes were found to be upregulated. We found altered TJ genes and proteins whose expression has not yet been associated with breast carcinoma. Our findings show a tendency of TJ genes and proteins to be downregulated in breast cancer. Further studies are necessary to examine whether the downregulation of the above mentioned TJ associated genes and proteins may contribute to the malignant progression of invasive ductal breast carcinomas.

Stromal matrix protein expression following preoperative systemic therapy in breast cancer.

PURPOSE: Stromal alterations are observed following preoperative systemic therapy in breast cancer. The aim of the present study was to analyze the qualitative and quantitative changes of representative tumor stroma proteins in the context of neoadjuvant therapy and the response of patients undergoing preoperative systemic therapy. EXPERIMENTAL DESIGN: Fifty women receiving preoperative systemic therapy were evaluated for clinical and pathologic parameters. Clinical response was defined according to International Union against Cancer (UICC) criteria, whereas pathologic responses to preoperative systemic therapy were defined according to the Chevallier and Sataloff classifications. The expression of tenascin-C, syndecan-1, collagen IV, and smooth muscle actin proteins was investigated using morphometric analysis of immunohistochemical reactions. Quantitative reverse transcription-PCR was done to evaluate the mRNA expression level of syndecan-1 and tenascin-C. The data were compared with 20 breast cancer samples of patients not treated with preoperative systemic therapy. RESULTS: According to UICC criteria, the expression levels of collagen IV were up-regulated in all preoperative systemic therapy-treated patients (P = 0.002). Collagen IV was up-regulated in the preoperative systemic therapy group in both Chevallier and Sataloff classifications compared with the control cases (P = 0.025 and P = 001, respectively). There were no significant differences in the expression of smooth muscle actin between the treated and nontreated groups. The syndecan-1 proteoglycan level was significantly down-regulated in the preoperative systemic therapy group (Chevallier classes P = 0.015, Sataloff classes P = 0.015). Tenascin-C was up-regulated in women with progressive disease (P = 0.005). CONCLUSION: We have observed that the stromal component of breast carcinomas following preoperative systemic therapy differs from the nontreated tumors, which can be evaluated with the analysis of the above mentioned proteins.

[Immunohistochemical phenotype of breast carcinomas predicts the effectiveness of primary systemic therapy]. / Az emlodaganatok primer szisztémás kemoterápiára adott válasza az immunhisztokémiai fenotípus tükrében.

The purpose of the study was to identify breast cancer subtypes by immunohistochemistry likely to respond to neoadjuvant chemotherapy and to analyze the used chemotherapy regimen and the range of response rates. Analysis of a collected database was performed. Ninety-two patients were identified in our files who received neoadjuvant chemotherapy between 1998 and 2009. We used immunohistochemical profiles (ER, PgR, HER2, Ki-67 and p53) of NCB, FNAB and surgical breast specimens to subclassify the tumors. Pathological response rates were assessed following surgical removal of tumors by using the Chevallier classification. DFS and OS was measured in 88 cases from the date of definitive surgery to the date of last follow-up or death. Pathological complete or near-complete remission (pCR = Chevallier I and II) was observed in 13 of 92 cases (14.1%). According to the preoperative characteristics of the 13 tumors achieving pCR, 9 of the cases were triple negative, one of 13 was ER-/HER2+ and three of 13 ER+/HER2+. Twenty-four of 92 patients received taxane based neoadjuvant chemotherapy, 30 of 92 anthracycline based neoadjuvant chemotherapy, 33 of 92 taxane + anthracycline regimen and 2 of 92 CMF regimen. In the taxane treated group of patients the pCR rate was 29.1%, in the anthracycline group 6.6% and in the taxane + anthracycline treated group 12.1%. Concerning DFS, significant difference was observed between the Chevallier III and IV groups (p=0.006), and less events were observed in the pCR group (not significant). pCR was associated with significantly better OS (p=0.050). It seems that even limited, routinely used immunohistochemical profiling of tumors is able to predict the likelihood of pCR to neoadjuvant chemotherapy. Patients with triple negative and HER2-positive cancers are likely to achieve pCR after neoadjuvant chemotherapy.

Expression of tight junction protein claudin-4 in basal-like breast carcinomas.

Claudins (CLDN) are tight junction proteins which contribute to the paracellular transport and ionic permeability of various epithelia. In recent years they came into focus for their suggested role in carcinogenesis and possible role in cancer therapy. According to our previous studies, in breast tissue CLDN4 is also related to the level of cellular differentiation. Thirty-eight estrogen (ER) and progesterone receptor (PgR) negative, HER2/neu negative, but cytokeratin 5/6 positive basal-like-mainly grade 3-breast carcinomas were compared with twenty-one grade 1, twenty-five grade 2 and twenty grade 3 non-basal-like invasive breast carcinomas, in respect to their CLDN4 expression. The immunohistochemical reactions were evaluated both semiquantitatively and by morphometrical analysis. Statistically significant difference (p = 0.001) was observable regarding CLDN4 expression in the basal-like group as compared to grade 1 and 2 cancers. Further, CLDN4 expression was significantly higher (p = 0.017) in the basal-like compared with the non-basal-like grade 3 carcinomas. Our results suggest that basal-like carcinomas are a subset of breast cancer with high level of CLDN4 protein expression. The finding is in accordance with our former observation that CLDN4 is indeed related to cellular differentiation. This observation may be seen as a further proof that basal-like carcinomas represent a separable group amongst grade 3 breast carcinomas.