Paired Metastatic Lymph Nodes Research Articles

Significance of nuclear p-mTOR expression in advanced oral squamous cell carcinoma with extracapsular extension of lymph node metastases

Traditional dichotomous extranodal extension (ENE) grading could not differentiate the risk of subsequent failure in advanced stage oral squamous cell carcinoma (OSCC) patients with ENE. This study investigated nuclear phosphorylated mammalian target of rapamycin (p-mTOR) expression in extranodal tumours and correlated this with clinical outcomes. A total of 218 advanced stage OSCC patients with neck lymph node metastasis were enrolled. Paired paraffin-embedded primary tumour and metastatic lymph node sections were stained with antibody against p-mTOR. Tumours with moderate-to-strong staining in ≧50% of tumour cells were recorded as being positive p-mTOR expression. The correlation of nuclear p-mTOR expression in extranodal tumours with clinicopathologic parameters was analysed. Nuclear p-mTOR expression in primary and extranodal tumours was highly associated with a lower grade of differentiation. The 5-year disease-free survival (DFS) of the patients without ENE, with and without positive nuclear p-mTOR expression in extranodal tumours was 54.3%, 23.4% and 55.2%, respectively. The 5-year overall survival (OS) of the patients without ENE, with and without nuclear p-mTOR expression in extranodal tumours was 55%, 18.7% and 51.3%, respectively. The patients with nuclear p-mTOR expression in extranodal tumours had significantly worse regional and distant disease control. Multivariate analysis also confirmed that nuclear p-mTOR expression in extranodal tumours was a significant independent adverse factor. Nuclear p-mTOR expression can be used as a prognostic indicator predictive of DFS and OS in advanced OSCC patients with ENE. There might be a possibility for targeted therapy in this group of patients.

ZNF703 promotes tumor cell proliferation and invasion and predicts poor prognosis in patients with colorectal cancer.

Zinc finger protein 703 (ZNF703), identified as an oncogene in luminal B breast cancer, is a member of the NET/NlZ family of zinc finger transcription factors. However, the role of ZNF703 in colorectal cancer (CRC) is unknown. We investigated the expression of ZNF703 in paired tumor and corresponding normal tissues using reverse transcriptase-polymerase chain reaction (RT-PCR) and western blot analysis. Immunohistochemistry (IHC) was applied on paraffin-embedded specimens, including 138 CRC tissues, 58 matched normal tissues and 30 paired metastatic lymph node samples. Levels of mRNA (72.72%, 16/22) and ZNF703 protein expression (65.38%, 17/26, respectively) were upregulated in CRC tissues. IHC staining revealed higher expression of ZNF703 in the CRC tissues (68/138, 49.3%) compared with that in the adjacent normal mucosal tissues (4/58, 6.9%) (p<0.001). Moreover, high ZNF703 expression was significantly correlated with tumor size, pathological grading, serosal invasion, lymph node metastasis and AJCC stage. CRC patients with relatively low ZNF703 expression had higher survival rates than those with high ZNF703 expression. In addition, we investigated ZNF703 expression in eight CRC cell lines (LS174T, SW480, HT29, SW620, DLD1, SW1116, LoVo and CaCo-2) invitro. The highest ZNF703 expression was detected in the LoVo cell line. RNA interference was used to assess the effects of ZNF703 knockdown in LoVo cells. Knockdown of ZNF703 expression inhibited CRC cell proliferation and migration. Collectively, these results reveal that ZNF703 may act as an oncogene in CRC and could be considered as a potential therapeutic target for metastatic CRC.

Caspase-3 expression in metastatic lymph nodes of esophageal squamous cell carcinoma is prognostic of survival.

To assess whether differential expression of caspase-3 in paired metastatic lymph nodes (LNs) is prognostic of survival in patients with resectable esophageal squamous cell carcinoma (ESCC). Capases-3 expression was evaluated immunohistochemically in 122 pairs of primary ESCCs and regional metastatic LNs assembled on tissue microarrays. The impact of caspase-3 expression on survival outcomes was analyzed by the Kaplan-Meier method and Cox proportional hazards regression model. The level of caspase-3 expression was significantly higher in LN metastases than in primary tumors (P < 0.001). Caspase-3 expression in the primary tumors was associated with longer median survival (23 mo vs 21 mo, P = 0.033), whereas higher expression in paired metastatic LNs was associated with shorter median survival (20 mo vs 22 mo, P = 0.043). Multivariate analysis showed that both were independent prognostic factors. Caspase-3 expression in metastatic LNs may be a potential independent predictor of poorer overall survival in patients with resected ESCC and LN metastasis. Protein expression in metastatic tumors may be a biomarker prognostic of survival.

Expression of the Epidermal Growth Factor Receptors and Ligands in Paired Samples of Normal Breast Tissue, Primary Breast Carcinomas and Lymph Node Metastases

Purpose: In breast cancer, the EGF receptors host an increasing number of therapeutic targets and the interactive mechanisms of actions of the receptors and their ligands justify investigation of the EGF family as an entity. Experimental design: Paired tissue samples of normal breast tissue and primary breast carcinomas were examined in a prospective study of 163 patients. A third sample was obtained from the paired ipsilateral metastatic lymph node from 58 of these patients. The mRNA expression of four EGF receptors (HER1 - HER4) and 11 activating ligands was quantified with real-time RT-PCR. Results: Expression of HER2, HER3, and HER4 mRNA was upregulated in primary carcinomas compared to normal breast tissue while HER1 was downregulated. The mRNA expression of HER3 and HER4 differed between primary breast carcinomas and lymph node metastases whereas there was no difference in the expression of HER1 and HER2. The combination of low HER3 and low HER4 expression in the primary carcinoma was significantly more frequent in lymph node-negative patients as compared to lymph node positive patients. Distinct correlation patterns of the receptors and their corresponding activating ligands appeared in both normal breast tissue and in carcinomas, notably for the HER3 and HER4 receptors and their 3 specific ligands: HB-EGF, NRG2, and NRG4. Conclusion: HER2, HER3, and HER4 showed increased mRNA expression in carcinomas and were positively correlated to each other and to specific activating ligands. Furthermore, low HER3 and HER4 expression in the carcinomas correlated to the absence of lymph node metastases.

Androgen and androgen-metabolizing enzymes in metastasized lymph nodes of breast cancer

Androgen receptor and androgen metabolizing enzymes, 17β-hydroxysteroid dehydrogenase type 5 (17βHSD5) and 5α-reductase1 (5α1), are frequently detected in primary tumor of breast cancer, but their status in metastatic lymph nodes has not been examined. The biological role of androgen in breast cancer and its metastatic process also remain unknown. In this study, we used immunohistochemistry to localize the expression of androgen receptor, 17βHSD5, and 5α1 in primary tumors and paired metastatic lymph nodes and correlated the findings with clinicopathologic factors of individual patients. Approximately 70% of primary tumors and paired metastatic lymph nodes expressed androgen receptor, with significant correlation between both lesions. However, 17βHSD5 and 5α1 immunoreactivity was decreased in metastatic lymph nodes. Alone or in tandem with androgen receptor, 5α1 was associated with significantly lower Ki-67 index, lower pathologic grade, and higher estrogen receptor positivity, but androgen receptor/5α1 double positivity in lymph nodes was associated with larger lymph node metastasis and higher TNM stage. In conclusion, androgen receptor immunoreactivity remained stable during the process of metastasis, whereas androgen-metabolizing enzymes decreased. Although results of our study and previous reports imply additional roles of androgen metabolism in the metastasis process, especially conversion by 5α1, there may be divergence between its effects on primary tumor and those in metastatic lymph nodes.

High expression of PRDM14 correlates with cell differentiation and is a novel prognostic marker in resected non-small cell lung cancer

PR (PRDI-BF1 and RIZ) domain containing proteins (PRDM) have been indicated to play important roles in several human cancers. The objectives of this study were to determine the frequency and prognostic significance of PRDM1 and PRDM14 expression in a cohort of surgically resected non-small cell lung cancer (NSCLC) patients. Immunohistochemistry and Western blotting was used to detect the expression status of PRDM1 in primary tumors and PRDM14 for both primary lung cancers and matched lymph node metastases. Univariate and multivariate analysis were performed to determine the association between PRDM expression and prognosis. PRDM1 expression was observed in all NSCLC patients' tumor samples. PRDM14 was found to be increased expression in 35.65 % cases (46/129) for primary tumors and 39.68 % cases (25/63) for paired metastatic lymph nodes. Increased expression of PRDM14 correlated with differentiation of tumor cells significantly (P = 0.008). Western blotting analysis verified that PRDM14 associated with cell differentiation in NSCLC. The overall survival rates of patients with high PRDM14 expression and low PRDM14 expression were 41.30 and 65.06 %, respectively (hazard ratio: 3.051, 95 % CI: 1.752, 5.312, P < 0.0001). The progression-free survival rates were 34.78 % for patients in the high expression group and 59.03 % for patients in the low OLC1 expression group (hazard ratio: 2.775, 95 % CI: 1.648, 4.675, P < 0.0001). Thus, our study showed that increased expression of PRDM14 correlated with cell differentiation of NSCLC cells. PRDM14 was a potential biomarker for predicting unfavorable prognosis in NSCLC.

Heterogeneity of ERBB2 in gastric carcinomas: a study of tissue microarray and matched primary and metastatic carcinomas

Trastuzumab in association with systemic cytotoxic chemotherapy is a therapeutic option for patients with advanced or metastatic ERBB2+ gastric carcinoma. The status of the ERBB2 overexpression or gene amplification is an important predictive marker in gastric cancer. However, it is controversial whether the primary tumor is representative of distant metastases in terms of ERBB2 status. Quadruplicated tissue microarrays from formalin-fixed paraffin-embedded tissues from 498 advanced primary gastric carcinomas and 97 matched metastatic lymph nodes were investigated by immunohistochemistry with HercepTest and silver in situ hybridization. For further comparison, another set of 41 paired primary and distant metastatic gastric carcinomas were also tested. Intratumoral heterogeneity was defined as different results between tissue microarray cores. ERBB2-positivity was observed in 52 gastric carcinomas (10%) and was not associated with recurrence of disease or survival of patients. In ERBB2-positive primary gastric carcinomas, heterogeneous ERBB2 overexpression was observed in 21/63 (33%) gastric carcinomas and heterogeneous ERBB2 gene amplification in 14/62 (23%) cases. Repeated immunohistochemistry and silver in situ hybridization in representative paraffin tumor blocks confirmed focal ERBB2 overexpression and ERBB2 gene amplification and did not change the final results. Discrepancies in ERBB2 results between primary and paired metastatic lymph nodes were observed in 11% of cases by immunohistochemistry and 7% by silver in situ hybridization. Out of the 41 paired primary and distant metastases, 5 (12%) cases were ERBB2-positive, and discrepancy was observed in one case. Intratumoral heterogeneity and discrepant ERBB2 results in primary and metastatic tumor are not uncommon in gastric carcinoma. Results of silver in situ hybridization showed less frequent heterogeneity compared with immunohistochemistry. Wherever possible, ERBB2 immunohistochemistry testing should be performed in both primary and distant metastatic sites.

Metastatic Lymph Node CHIP Expression is a Potential Prognostic Marker for Resected Esophageal Squamous Cell Carcinoma Patients

C-terminal Hsp-interacting protein (CHIP) is an HSP70 and HSP90 interacting co-chaperone and an E3 ubiquitin ligase. Previous studies have reported the role of CHIP in cancer progression by targeting protein degradation. However, its role and clinical significance in esophageal squamous cell carcinoma (ESCC) has not been elucidated. We investigated the correlation of CHIP expression and clinical outcome in a group of T3N1-3M0 surgically resected ESCCs. Tissue microarrays constructed of 234 surgically resected T3N1-3M0 ESCC primary tumors (PTs) and 163 paired metastatic lymph nodes (MLNs), and sections of 56 cancer-adjacent normal epithelial blocks were used for CHIP evaluation by immunohistochemistry. The clinical and prognostic significance of CHIP expression was analyzed statistically. The expression level of CHIP in ESCC MLNs was significantly higher than that in PTs (P < 0.001). Patients with low MLNs' CHIP expression demonstrated better overall survival than those with high CHIP expression (median, 44 vs. 17.9 months; P = 0.010). Multivariate analysis showed that the MLNs' CHIP expression level was an independent prognostic factor in ESCC (relative risk, 2.157; P = 0.028). High expression of CHIP in MLNs suggests poor prognosis for patients with resected T3N1-3M0 ESCC. The result suggests that considering the protein expression of metastatic tumors is important for prognostic prediction.

Increased levels of SLP-2 correlate with poor prognosis in gastric cancer

Stomatin-like protein 2 (SLP-2) is a member of the highly conserved stomatin protein family whose homologues span from Archaea to humans and include stomatin, SLP-1, and SLP-3. Several studies have indicated that overexpression of SLP-2 is strongly associated with adhesion and migration in several human cancers. The aim of the present study was to evaluate SLP-2 expression at the mRNA and protein level in patients with gastric cancer (GC) and to examine the relationships between SLP-2 expression, clinicopathological features, and prognosis. We investigated SLP-2 expression in primary GC and paired normal gastric tissue by real-time PCR (RT-PCR; n = 16) and Western blot analysis (n = 32). Additionally, we performed immunohistochemistry (IHC) on 113 paraffin-embedded GC specimens, 30 matched normal specimens, and 30 paired metastatic lymph node samples. SLP-2 is overexpressed in GC compared with the adjacent normal gastric epithelium (p < 0.001), and high-level SLP-2 expression is significantly correlated with the depth of invasion, lymph node metastasis, distant metastasis, and American Joint Committee on Cancer (AJCC) stage. Furthermore, elevated SLP-2 expression is an independent prognostic factor in multivariate analysis using the Cox regression model (p = 0.005). Overexpression of SLP-2 may contribute to the progression and poor prognosis of GC.

The role of the CDH1 promoter hypermethylation in the axillary lymph node metastasis and prognosis.

PurposeHypermethylation of the tumor suppressor genes is frequently observed in the tumor development and progression. However, the correlation between the hypermethylation of the tumor suppressor genes, CDH1 and the axillary lymph node (ALN) metastasis is not fully elucidated. To verify the role of the CDH1 promoter hypermethylation in the ALN metastasis and prognosis, we compared the methylation status of the CDH1 genes in the primary lesion and the paired metastatic ALNs.MethodsWe selected a total of 122 paraffin-embedded specimens of the primary and paired metastatic lymph node from 61 breast cancer patients and analyzed the frequency of hypermethylation in the primary and metastatic lymph node using the methylation-specific polymerase chain reaction. In addition, the methylation status of CDH1 was analyzed with the clinicopathologic characteristics, the disease-free survival and disease-specific survival.ResultsThe hypermethylation of CDH1 gene was identified in 54 (88.5%) of the 61 patients who had axillary metastasis. The hypermethylation status of the CDH1 gene was significantly increased in the metastatic ALNs compared with that in the primary tumors (60.7% vs. 45.9%, p<0.001). The hypermethylation status of the CDH1 genes in the metastatic ALNs was associated with a poor histologic grade (p=0.041) and the patients who had methylated tumor in the primary lesion showed worse disease-free survival than the patients who did not have methylated tumor (p=0.046).ConclusionThis study suggests that hypermethylation of the CDH1 gene may play a pivotal role in the metastasis of the axillary lymph node and the breast cancer recurrence.

Immunohistochemical analysis of aromatase in metastatic lymph nodes of breast cancer

Aromatase is the key enzyme in intratumoral estrogen production in postmenopausal breast cancer and third generation aromatase inhibitors suppress this enzymatic reaction effectively. Aromatase inhibitor is administered to metastatic breast cancer patients customarily in which estrogen receptor had been demonstrated only in the primary tumor, not the metastatic sites. The status of aromatase in metastatic sites has not been well-characterized to date. We immunolocalized aromatase in 46 estrogen receptor positive primary breast cancers and paired metastatic lymph nodes, using immunohistochemistry. Immunoreactivity was detected in 44/46 primary tumors and 40/46 metastatic lymph nodes. A significant correlation was detected between the status of aromatase in primary and metastatic sites. Aromatase immunoreactivity was correlated with age, size of primary tumor and Ki-67 index. Aromatase immunoreactivity was also detected in adipose tissue surrounding the lymph nodes. In conclusion, aromatase status in primary tumors generally represents its status in metastatic lymph nodes. This indicates that the endocrine environment of estrogen receptor positive tumors remain stable during the metastatic process.

Abstract P2-05-07: Comparison of hormone receptor and HER-2 expression in primary breast cancers and sentinel lymph node metastases

Abstract Background: Recently, it is a hot topic that the estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor type 2 (HER2) may differ between the primary tumors and the paired recurrent metastatic tumors. On the other hand, the concordance of the ER, PR, and HER2 status between the primary tumor and ipsilateral axillary lymph node metastases is reported to be high in previous study. However, in these reports, the majority of lymph nodes metastases examined are macrometastases obtained from axillary lymph node dissection. The aim of the present study is to compare the ER, PR, and HER2 status of the primary breast tumors with that of sentinel lymph node micrometastases and macrometastases. Methods: A total of 770 breast cancer patients underwent sentinel lymph node biopsy between 2006 and 2010 at our hospital. Among them, 87 patients who had only one node positive were eligible for our study. ER, PR, and HER2 status were determined by immunohistochemistry (IHC) and/or FISH. Result: We analyzed 76 patients with 50(66%) patients with macrometastasesn and 26 (34%) micrometastases, except 11 cases those were indeterminate for IHC. ER status of primary tumor and the paired metastatic lymph node were almost full concordance except one case, in which ER was negative in primary tumor but ER was positive in lymph node. Discordance for PR was 15.8% (n = 12). Among these, six patients had PR-positive on primary and PR-negative in lymph node while six patients had PR-negative in primary and PR-positive in lymph node. Discordance for HER2 between primary tumor and metastatic lymph node was 5.3% (n = 4). Among these, three had negative in primaries and positive in lymph nodes while one had positive in primary and negative in lymph node. A discordance between primary and lymph node in HER2, ER, or PR status was observed in 14 of 67 (18.4%) cases. Conclusions: The concordance in HER2, ER, and PR was high between the primary tumor and sentinel lymph nodes. However some cases had discordance of receptor status and these result may cause of discordance for distant metastases or poor prognosis. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-05-07.

Clinicopathological Significance of NMIIA Overexpression in Human Gastric Cancer

Altered expressions of nonmuscle myosin IIA (NMIIA) have been observed in certain types of cancers, but the impact of the alterations in gastric cancer (GC) remains unclear. The purpose of this study was to evaluate the expression of NMIIA at the mRNA and protein level in patients with GC and to assess its clinical significance. We investigated the expression of NMIIA in fresh, paired GC tissues by reverse transcriptase polymerase chain reaction (RT-PCR; n = 14) and Western blot analysis (n = 36). Simultaneously, we performed immunohistochemistry (IHC) on paraffin embedded specimens, including 96 GC specimens, 30 matched normal specimens and 30 paired metastatic lymph node samples. NMIIA is overexpressed in GC compared with the adjacent normal gastric epithelium (p < 0.001) and high-level NMIIA expression is significantly correlated with the depth of wall invasion, lymph node metastasis, distant metastasis and Tumor Node Metastasis (TNM) stage. Furthermore, elevated NMIIA expression is an independent prognostic factor in multivariate analysis using the Cox regression model (p = 0.021). These findings indicate that overexpression of NMIIA may contribute to the progression and poor prognosis of GC.

Heterogeneity of COX-2 and Multidrug Resistance between Primary Tumors and Regional Lymph Node Metastases of Gastric Cancer

Cyclooxygenase-2 (COX-2) is involved in the progression of gastric cancer; however, the role of COX-2 in multidrug resistance (MDR) is still unclear. This study aimed to elucidate the relationship between COX-2 and MDR so as to show the heterogeneity of gastric primary tumors and regional lymph node metastases. Between 2008 and 2009, 56 primary tumor samples and paired metastatic lymph node tissues from gastric cancer patients confirmed by surgery and pathological examination in our hospital were collected. The expression levels of COX-2 and MDR-associated factors such as P-glycoprotein (P-gp), glutathione S-transferase pi (GST-π) and topoisomerase II alpha (Topo-II-α) were determined by immunohistochemical staining. Tumor cells from these tissues were cultured and the cell chemosensitivities for 11 chemotherapeutic agents were measured by sulforhodamine B assay. The expression levels of COX-2, P-gp and GST-π were significantly higher in metastatic lymph node tissues than in primary tumors, while the expression level of Topo-II-α was lower in metastatic lymph node tissues than in primary tumors (all P <0.05). In primary tumors, COX-2 and GST-π were positively correlated and COX-2 and Topo-II-α were negatively correlated; in metastatic lymph node tissues, a positive correlation was found between COX-2 and P-gp (all P <0.05). The inhibition rates of eADM, VP-16, THP and MMC on cells from primary tumors were significantly lower than those on cells from metastatic lymph nodes, while the inhibition rates of HCPT, L-OHP and VCR on cells from metastatic lymph nodes were lower than those on cells from primary tumors. The expression of COX-2 and MDR-associated factors as well as cell chemosensitivities are different in primary tumors and regional lymph node metastases of gastric cancer, and this may be an indication of their heterogeneity.

Stat3 Mediates Expression of Autotaxin in Breast Cancer

We determined that signal transducer and activator of transcription 3 (Stat3) is tyrosine phosphorylated in 37% of primary breast tumors and 63% of paired metastatic axillary lymph nodes. Examination of the distribution of tyrosine phosphorylated (pStat3) in primary tumors revealed heterogenous expression within the tumor with the highest levels found in cells on the edge of tumors with relatively lower levels in the central portion of tumors. In order to determine Stat3 target genes that may be involved in migration and metastasis, we identified those genes that were differentially expressed in primary breast cancer samples as a function of pStat3 levels. In addition to known Stat3 transcriptional targets (Twist, Snail, Tenascin-C and IL-8), we identified ENPP2 as a novel Stat3 regulated gene, which encodes autotaxin (ATX), a secreted lysophospholipase which mediates mammary tumorigenesis and cancer cell migration. A positive correlation between nuclear pStat3 and ATX was determined by immunohistochemical analysis of primary breast cancer samples and matched axillary lymph nodes and in several breast cancer derived cell lines. Inhibition of pStat3 or reducing Stat3 expression led to a decrease in ATX levels and cell migration. An association between Stat3 and the ATX promoter, which contains a number of putative Stat3 binding sites, was determined by chromatin immunoprecipitation. These observations suggest that activated Stat3 may regulate the migration of breast cancer cells through the regulation of ATX.

Variation d’expression des récepteurs hormonaux et d’HER-2 dans l’évolution du cancer du sein : quelles implications en pratique clinique ?

Breast cancer remains a major public health problem. Even if there is an increase in this cancer curability, metastatic breast cancer remains a lethal disease in the vast majority of cases. Therapeutic advances in the chemotherapeutic and targeted therapies fields induced an increase in survival, however the proportion of long survivors remains low. Phenotypic instability, an early process initiated during tumour progression, and continued on the metastatic stage of the disease, can be one of the putative hypotheses explaining these results. An increasing amount of scientific data are pledging for a reanalysis of the phenotypic profile regarding hormone receptors and HER-2 status of metastatic lesions in order to identify drugable targets and allow individualisation of the treatment of these metastatic breast cancer patients. Phenotypic changes between the primary tumour and the paired metastatic lymph nodes are a challenging pitfall, raising the question of which site has to be assessed in the adjuvant treatment decision process. This article presents a comprehensive analysis of the frequency of theses phenotypic changes altogether with new modalities to evaluate this phenotypic status.

Abstract 539: The expression of monocyte/macrophage-restricted scavenger receptor CD163 by malignant cells may be a consequence of cell fusion with tumor-associated macrophages: A novel target for cancer therapy

Abstract Solid tumors contain large a number of infiltrating macrophages, which are believed to play a key role in progression and metastasis. Recent research has indicated that malignant cells at times express molecular pathways normally only observed in myeloid cells such as macrophages, hence suggesting that macrophages may fuse with tumor cells. In the present work, we aimed to investigate tumor cell expression of the monocyte/macrophage-restricted scavenger receptor CD163. Initially, the tumor expression of CD163 was examined using a bladder cancer tissue microarray (TMA) containing 425 cores of tumor tissue from 425 patients and 43 paired metastatic lymph nodes. Tumor cells showed a characteristic pleomorphic and atypical morphology with large nuclei, and they were easily distinguished from macrophages. Immunohistochemical staining revealed that CD163-expressing tumor cells could be detected in 98% of the tumor cores, and CD163-expressing metastatic cells could be identified in 77% of the cores of lymph node biopsies. Quantitative real-time polymerase chain reaction and flow cytometric analysis showed that bladder cancer cell lines did not express CD163; however, when co-cultured with macrophages a significant induction of CD163 expression was observed. Utilizing the xCELLigence Real-Time Cell Analyzer System we showed that macrophage-tumor hybrid cells exhibited a significantly increased migratory capacity compared to non-hybrid tumor cells. Tracing the Y chromosome in co-cultures of male macrophages and female T24 cells, we found T24 cell nuclei to be fused with the macrophages. A Cre-inducible mouse model of melanoma expressing a fluorescent reporter system (GFP) was used to characterize hybrid cell formation of macrophages with GFP positive tumors cells in vivo. Flow cytometric analysis demonstrated that &amp;gt;90% of the murine GFP positive tumor cells co-expressed CD163. In conclusion, we show that the expression of the monocyte/macrophage scavenger receptor CD163 was not confined to tumor-associated macrophages. In fact, a significant portion of the tumor cells also expressed CD163, possibly as a result of heterotypic cell fusion between tumor cells and macrophages. Our findings identify CD163 as a possible target for novel cancer therapy. 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 539. doi:10.1158/1538-7445.AM2011-539

Discordance of Molecular Biomarkers Associated with Epidermal Growth Factor Receptor Pathway between Primary Tumors and Lymph Node Metastasis in Non-small Cell Lung Cancer

For the identification of the patients who most likely benefit from epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC), molecular assays are considered to be of paramount importance. Given the heterogeneity of NSCLC at the molecular level, this study was conducted to determine the discrepancy in EGFR mutations between primary tumors and the corresponding lymph node metastasis. Surgically resected 101 paired primary NSCLC and metastatic lymph nodes were evaluated for the EGFR mutations by direct DNA sequencing and heteroduplex analysis. EGFR mutation was detected in 29.7% (30 of 101) of the primary tumors and in 27.7% of lymph node metastases (28 of 101) by either direct sequencing or heteroduplex analysis, respectively. By direct sequencing, 12 cases (11.9%) showed discordance in EGFR mutations between primary tumors and metastasis. In 11 cases, EGFR mutations were detected only in the primary tumor, whereas 1 case only in lymph node metastases. By heteroduplex analysis, 17 cases (16.8%) were discordant. Ten cases were primary tumor positive and lymph node negative, whereas seven cases were lymph node positive and primary tumor negative. A considerable proportion of NSCLC showed discrepancy in EGFR mutations between primary tumors and metastatic lymph nodes, suggesting tumor heterogeneity at the molecular level during the process of metastasis.

BP1, a putative signature marker for inflammatory breast cancer and tumor aggressiveness1

Our previous studies revealed that beta protein 1 (BP1) was barely detectable in normal human breasts, but was seen in 21%, 46%, and 81% of hyperplastic, in situ, and invasive breast lesions, respectively. Our current study attempted to assess BP1 expression in inflammatory breast cancer (IBC), a very aggressive subtype of breast cancers characterized by extensive lympho-vascular invasion and involvement of dermal lymphatics. Paraffin-embedded tissue sections from 45 cases of IBC (nine with paired metastatic lymph nodes) and different controls were assayed immunohistochemically for BP1 expression. Positive BP1 immunoreactivities were present in all IBC cases. Strikingly, all cancer cells metastasized to lymph nodes and cells within lymphatic channels were uniformly and strongly immunoreactive to BP1. The percentage of BP1 positive cells and the intensity of BP1 immunostaining in IBC cases were significantly greater than those in non-IBC cases. Our findings suggest that BP1 may possess properties of onco-proteins that promote tumor progression, invasion, and metastasis, representing a putative signature marker for IBC and tumor aggressiveness.

A gene expression signature that defines breast cancer metastases

The most important predictor of prognosis in breast cancer is lymph node status, yet little is known about molecular changes associated with lymph node metastasis. Here, gene expression analysis was performed on primary breast (PBT) and corresponding metastatic lymph node (MLN) tumors to identify molecular signatures associated with nodal metastasis. RNA was isolated after laser microdissection from frozen PBT and MLN from 20 patients with positive lymph nodes and hybridized to the microarray chips. Differential expression was determined using Mann-Whitney testing; Bonferroni corrected P values of 0.05 and 0.001 were calculated. Results were validated using TaqMan assays. Fifty-one genes were differentially expressed (P < 1 x 10(-5), less than twofold differences) between the PBT and paired MLN; 13 with significantly higher expression in the MLN and 38 in the PBT. qRT-PCR validated the differential expression of 40/51 genes. Of the 40 validated genes, NTS and PAX5 were found to have >100-fold higher expression in MLT while COL11A1, KRT14, MMP13, TAC1 and WNT2 had >100-fold higher expression in PBT. Gene expression differences between PBT and MLN suggests that expression of a unique set of genes is required for successful lymph node colonization. Genes expressed at higher levels in PBT are involved in degradation of the extracellular matrix, enabling cells with metastatic potential to disseminate, while genes expressed at higher levels in metastases are involved in transcription, signal transduction and immune response, providing cells with proliferation and survival advantages. These data improve our understanding of the biological processes involved in successful metastatis and provide new targets to arrest tumor cell dissemination and metastatic colonization.