Extracellular matrix expression in metastasizing and nonmetastasizing adenocarcinomas of the lung

Proteomic analysis reveals LRPAP1 as a key player in the micropapillary pattern metastasis of lung adenocarcinoma

Objectives

Lung adenocarcinomas have different prognoses depending on their histological growth patterns. Micropapillary growth within lung adenocarcinoma, particularly metastasis, is related to dismal prognostic outcome. Metastasis accounts for a major factor leading to mortality among lung cancer patients. Understanding the mechanisms underlying early stage metastasis can help develop novel treatments for improving patient survival.

Methods

Here, quantitative mass spectrometry was conducted for comparing protein expression profiles among various histological subtypes, including adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive adenocarcinoma (including acinar and micropapillary [MIP] types). To determine the mechanism of MIP-associated metastasis, we identified a protein that was highly expressed in MIP. The expression of the selected highly expressed MIP protein was verified via immunohistochemical (IHC) analysis and its function was validated by an in vitro migration assay.

Results

Proteomic data revealed that low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1) was highly expressed in MIP group, which was confirmed by IHC. The co-expressed proteins in this study, PSMD1 and HSP90AB1, have been reported to be highly expressed in different cancers and play an essential role in metastasis. We observed that LRPAP1 promoted lung cancer progression, including metastasis, invasion and proliferation in vitro and in vivo.

Conclusion

LRPAP1 is necessary for MIP-associated metastasis and is the candidate novel anti-metastasis therapeutic target.

CTNNB1 S37C mutation causing cells proliferation and migration coupled with molecular mechanisms in lung adenocarcinoma

Background

This study aimed to investigate the potential cytological effects and molecular mechanisms of β-catenin (CTNNB1) S37C mutation in lung adenocarcinoma (LUAD).

Methods

CTNNB1 with S37C mutation were transfected into LUAD cell lines. The expression of β-catenin were determined using Western blot. Cell proliferation and migration were detected using cell counting kit-8 (CCK-8) assay and wound healing assay, respectively. Transcriptome sequencing was performed on LUAD cells with CTNNB1 S37C mutation (CTNNB1 mutation group) and LUAD cells without treatment (Control group), followed by the screening of differentially expressed genes (DEGs). Functional enrichment analysis and protein-protein interaction (PPI) analysis were performed for the DEGs. Finally, the expression of key DEGs were validated by quantitative real-time PCR (qRT-PCR).

Results

CTNNB1 with S37C mutation was successful expressed in 2 cell lines. Cells proliferation and migration were significantly promoted in mutation group in comparison with that of Control group (P<0.05). A total of 180 DEGs were revealed between Control and CTNNB1 mutation groups. These DEGs were mainly enriched in extracellular matrix function and nicotine addiction pathway. PPI network contained 51 DEGs and 45 interactions. PTPRD, GNG7 and CNTN1 were hub genes in PPI network with higher degree. CGB5 interacted with PTPRU, while IGFBP3 showed interaction with MMP1. Results of qRT-PCR confirmed the expression of several key DEGs in transcriptome analysis.

Conclusions

CTNNB1 S37C mutation contributed the LUAD cells proliferation and migration. PTPRD, IGFBP-3, MMP1 and PTPRU might play roles in the effect of CTNNB1 S37C mutation in LUAD.

Transcriptomic Profiling of In Vitro Tumor-Stromal Cell Paracrine Crosstalk Identifies Involvement of the Integrin Signaling Pathway in the Pathogenesis of Mesenteric Fibrosis in Human Small Intestinal Neuroendocrine Neoplasms

Aim

Analysis of the pathophysiology of mesenteric fibrosis (MF) in small intestinal neuroendocrine tumors (SI-NETs) in an in vitro paracrine model and in human SI-NET tissue samples.

Methods

An indirect co-culture model of SI-NET cells KRJ-I and P-STS with stromal cells HEK293 was designed to evaluate the paracrine effects on cell metabolic activity, gene expression by RT2 PCR Profilers to analyse cancer and fibrosis related genes, and RNA sequencing. The integrin signaling pathway, a specific Ingenuity enriched pathway, was further explored in a cohort of human SI-NET tissues by performing protein analysis and immunohistochemistry.

Results

RT Profiler array analysis demonstrated several genes to be significantly up- or down-regulated in a cell specific manner as a result of the paracrine effect. This was further confirmed by employing RNA sequencing revealing multiple signaling pathways involved in carcinogenesis and fibrogenesis that were significantly affected in these cell lines. A significant upregulation in the expression of various integrin pathway – related genes was identified in the mesenteric mass of fibrotic SI-NET as confirmed by RT-qPCR and immunohistochemistry. Protein analysis demonstrated downstream activation of the MAPK and mTOR pathways in some patients with fibrotic SI-NETs.

Conclusion

This study has provided the first comprehensive analysis of the crosstalk of SI-NET cells with stromal cells. A novel pathway – the integrin pathway – was identified and further validated and confirmed in a cohort of human SI-NET tissue featured by a dual role in fibrogenesis/carcinogenesis within the neoplastic fibrotic microenvironment.

Expression Analysis of Angiogenesis-Related Genes in Bulgarian Patients with Early-Stage Non-Small Cell Lung Cancer

Aims and background

Angiogenesis is a key process in the early stages of tumor development. In this study we aimed to evaluate the expression of a panel of angiogenesis-related genes in a group of Bulgarian patients with early-stage non-small cell lung cancer (NSCLC).

Methods and study design

We analyzed the expression of 84 genes associated with the angiogenic process in 12 NSCLCs of two histological subtypes: 7 adenocarcinomas and 5 squamous cell carcinomas. Eight peripheral nontumorous tissues were used as controls. We performed real-time PCR on pathway-specific gene arrays (SABiosciences).

Results

Our pilot study identified upregulated genes in early-stage NSCLC including growth factors (TGFA and EFNA3), the adhesion molecule THBS2, cytokines and chemokines (MDK, CXCL9, CXCL10), and the serine protease PLAU. Several genes showed downregulation including one growth factor (FIGF), the receptors for growth factors TEK and S1PR1 as well as adhesion molecules (COL4A3 and CDH5), the cytokine IL6, the matrix protein LEP and the transcription factor NOTCH4. The study demonstrated deregulated genes specific for the two histological subtypes including the transcription factor HAND2, which was overexpressed in squamous cell carcinomas but not adenocarcinomas.

Conclusions

Despite the limited number of patients, our results demonstrated the potential of angiogenesis-related genes as biomarkers in the early stages of NSCLC development. Free full text available at www.tumorionline.it

Comparison of in vivo probe-based confocal laser endomicroscopy with histopathology in lung cancer: A move toward optical biopsy

BACKGROUND AND OBJECTIVE

The development of novel technologies has increased the yield from transbronchial biopsies while preserving patient safety by guiding biopsies to the area of interest. Other technologies have helped identify pre-cancerous or sessile lesions in the endobronchial space by utilizing interactions between tissue and light at varying wavelengths. Probe-based confocal laser endomicroscopy (pCLE) is a new technology that encompasses the benefits of both guided biopsies and novel optical imaging in one device. This project compares pCLE images to the findings of light microscopy in non-small cell lung cancer (NSCLC).

METHODS

Patients who underwent bronchoscopies between July 2012 and January 2013 for evaluation of pulmonary lesions (transbronchial and endobronchial) were recruited. Histopathological images from malignant lesions were compared with the pCLE images obtained from the same area. The microscopic and pCLE images were reviewed side by side with the microscopic findings.

RESULTS

Images from pCLE correlate with some histopathological findings. pCLE changes seen in NSCLC consist of mottled elastin, septal studding and disorganization/fragmentation with increased friability. These changes also seem to correlate with degrees of differentiation.

CONCLUSIONS

pCLE can identify changes to the elastin composition of the airways and alveoli in lung cancer. These changes correlate with histopathology and may help indicate the presence of malignant changes in vivo.

Novel α(2)β(1) integrin-targeted peptide probes for prostate cancer imaging

Accumulating experimental evidence indicates that overexpression of α(2)β(1) integrin may correlate with progression in human prostate cancer. The objective of this study was to design a novel imaging probe based on the Asp-Gly-Glu-Ala (DGEA) peptide for near-infrared-fluorescent (NIRF) imaging of α(2)β(1) integrin expression in prostate cancer. The peptides were conjugated with appropriate fluorescent dyes, and the binding affinity of these probes was evaluated by flow cytometry in three human prostate cell lines (PC-3, CWR-22, and LNCaP). In vivo NIRF imaging of the α(2)β(1)-positive PC-3 xenograft model was performed to evaluate the α(2)β(1) targeted probe. In vitro immunofluorescence staining was carried out to confirm the α(2)β(1) integrin expression level. Flow cytometry analysis showed that PC-3 had the highest probe uptake, followed by CWR-22 and LNCaP tumor cells. In the subcutaneous PC-3 model, the tumor demonstrated prominent uptake with good tumor to background contrast. Immunohistochemistry staining also supported the in vivo optical imaging results. DGEA-based optical agents have been developed for specific imaging of α(2)β(1) integrin expression. In vitro and in vivo localization demonstrated the potential of this agent to identify tumor subtypes amenable to anti-α(2)β(1) integrin treatment and potentially provide prognostic information regarding tumor progression.

[Assessment of tissue inhibitor of metalloproteinases-2 (TIMP-2) in laryngeal cancer]

Metalloproteinases are the proteolytic enzymes that digest components of the extracellular matrix in many physiological and pathological conditions. Their activity is regulated by their natural inhibitors: non-specific alpha2-macroglobulin and specific tissue inhibitors of metalloproteinases (TIMP). There are four TIMPs. TIMP-2 is the only enzyme that is expressed in constitutive manner and has the ability to inhibit activity of all metalloproteinases. TIMP-2 has been identified in many carcinomas including cancers of lung, oral cavity, breast and colon. There was correlation between TIMP-2 expression and clinical course of the disease observed in most of the neoplasm.

AIM

The aim of the research was to evaluate the expression of TIMP-2 in laryngeal cancer and to assess the prognostic significance of this factor.

MATERIAL AND METHOD

104 patients with laryngeal cancer, that underwent surgical treatment were included in the study. Only cases with at least a 5-year follow-up were included. Immunohistochemical studies were performed on formalin fixed, paraffin embedded sections by using monoclonal antibodies against TIMP-2 antigen and ABC detection system.

RESULTS

TIMP-2 expression was cytoplasmatic, mainly in cancer cells, but also in some stromal cells. There was correlation between TIMP-2 expression and tumor size and grading observed. We didn't find any correlation between TIMP-2 and nodal metastases, recurrence and survival.

CONCLUSIONS

Our results don't suggest that TIMP-2 expression may be used as a prognostic factor in patients with laryngeal cancer. Nevertheless there are more researches needed to explain the role of TIMPs in growth and progression of neoplastic tumors.

Growth pattern correlates with the distribution of basement membrane and prognosis in lung adenocarcinoma

Lung adenocarcinoma frequently has a histologic heterogeneity, particularly with regard to its cell morphology and growth pattern, with or without stromal desmoplasia. However, little is known about the relationship between morphologic heterogeneity and the destruction of BM. We selected 147 foci showing different growth patterns studied in 76 patients with lung adenocarcinoma and examined immunohistochemically the distribution of BM antigens, as well as the expression of MMPs and TIMP-2. BM antigens were more highly preserved in foci of the BAC growth pattern (94.7%) than in those of the papillary/acinar (24.5%) and solid patterns (16.1%) (p<0.01). MMP-2-positive cancer cells were significantly more frequent in poorly preserved foci of BM antigens than in preserved foci (p<0.05). The population of TIMP-2-positive cancer cells showed a positive correlation with BM preservation (p<0.05). However, no significant relationship between growth pattern and expression of MMP-9 and -14 was found. BM antigens had almost totally disappeared in desmoplastic foci. Multivariate analyses revealed that pathologic stage and high expression of TIMP-2 were independent prognostic factors. These findings indicate that the histologic heterogeneity of lung adenocarcinomas is partly related to the cancer cell-stromal interaction, in particular through BM preservation or destruction, which was mainly affected by cancer cell expression of MMP-2 and TIMP-2 in lung adenocarcinomas.

Immunohistochemical expression of integrins and extracellular matrix proteins in non-small cell lung cancer: correlation with lymph node metastasis

PURPOSE

For patients with non-small cell lung cancer (NSCLC), the biggest threat to survival is metastasis. During metastatic cascade, tumor cells interact with extracellular matrix (ECM) through certain adhesion molecules such as integrins. The aim of this study was to analyze the distribution of the main integrins and ECM in a series of patients with NSCLC to assess their distribution and correlate with lymph node (LN) metastasis of NSCLC.

METHODS

Formalin-fixed and paraffin-embedded tissues of NSCLC with (n=45) or without (n=23) regional LN metastasis were obtained form 68 surgically treated patients. The expression of fibronectin, collagen type IV, tenascin and the integrin subunits (alpha2, alpha3, alpha4, alpha5 and beta1) was studied by immunohistochemistry. Chi-square and Fisher's exact tests were used to compare groups and parameters.

RESULTS

Extensive (>50% of section area) fibronectin and collagen type IV staining were seen in 22 and 55% of tumors, respectively, with focal areas of immunoreactivity seen in another 75 and 38% of tumors, respectively. Tenascin staining showed just focal areas of immunoreactivity in 21% of tumors. Interstitial collagen matrices were more frequently lost in LN metastasis (P=0.007). Integrins alpha2, alpha5 and beta1 expressions were present in 9, 12 and 26% of tumors, respectively. The expression of integrins alpha5 and beta1 was significantly associated with LN metastasis (P=0.04 and 0.005, respectively).

CONCLUSIONS

Increased expression of integrins alpha5 and beta1, and lost expression of collagen matrices significantly correlated with LN metastasis of NSCLC. These findings suggested that enhanced expression of integrins and disrupted collagen stroma in NSCLC might promote tumor cell survival and invasiveness.

Novel therapies for lung cancer

Lung cancer remains the leading cause of cancer mortality in the US. For the majority of patients with advanced non-small cell lung cancer, chemotherapy with or without radiation therapy is the mainstay of treatment. Despite the modest improvement in survival for these patients, prognosis remains dismal. However, the expanding knowledge of tumor biology in recent years has resulted in the promising development of a new class of "molecularly targeted" agents, which selectively target cancer cells at the molecular, biochemical, and genetic level, thus minimizing toxic effects on normal tissues. A wide range of molecularly targeted agents are being actively investigated in lung cancer therapy as single agents or in combination with conventional modalities. In this review, we discuss some of the agents furthest along in development: epidermal growth factor receptor inhibitors, anti-angiogenic agents, inhibitors of biologically important enzymes such as matrix metalloproteinases and farnesyltransferase, gene therapy including gene replacement and antisense therapy, and cell cycle disruptors.

Clinical impact of novel treatment strategies

Following two decades of research on the biology of cancer and in particular of lung cancer, we have now a large number of molecular targets that can be utilized to create specific medicines against these cancers. Non-small cell lung cancer represents numerically the most important solid tumor in Western world, and is poorly affected by current therapies, where surgery represents almost the only curative therapy for about 25% of patients who are resectable at diagnosis. An abundant number of targeted therapies are being investigated in NSCLC. Among them are the metalloproteinase inhibitors, several tyrosine kinase inhibitors and several attempts of gene replacement have also been made. Promising results have so far been obtained with some of these approaches, and the outcome of large randomized studies is awaited. Small cell lung cancer (SCLC) represents about 20% of lung carcinomas, and several of the novel approaches that are being attempted for NSCLC, are also being investigated for SCLC. All these novel therapies open a new era of anticancer treatment that will likely complement the currently available therapies in the near future.

Appearance of osteonectin-expressing fibroblastic cells in early rat stomach carcinogenesis and stomach tumors induced with N-methyl-N'-nitro-N-nitrosoguanidine

The present study was designed to define molecular alterations in the initiation stage of rat stomach carcinogenesis. Groups of male Lewis rats, 6 weeks old, were given drinking water with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG; 100 mg/liter). Total RNA was isolated from the stomach pyloric mucosa, and fluorescent differential display analysis was performed. A cDNA fragment of 125 bp encoding an extracellular matrix-associated matricellular glycoprotein, osteonectin, was identified after 14 days of MNNG exposure. A severalfold increase in expression was observed after 14 and 27 days of MNNG exposure, as determined by northern blot and RT-PCR. Immunohistochemistry revealed that osteonectin-mAb-stained fibroblastic cells appeared in interstitial tissue of pyloric mucosa. Additionally the gene expression of other extracellular matrix proteins, viz., collagen type III, fibronectin, osteopontin, proteoglycan NG2, laminin gamma1 and S-laminin, was also markedly increased, as determined by competitive RT-PCR after 14 days of MNNG exposure. The gene expression of osteonectin and the six other extracellular matrix proteins was elevated in twelve stomach adenocarcinomas and adenomas induced by MNNG in Lewis and WKY rats. Osteonectin-mAb-stained fibroblastic cells were evident in interstitial tissue of stomach tumor. These results suggest that osteonectin-expressing fibroblastic cells appear in the interstitial tissue of pyloric mucosa from the early initiation stage of rat stomach chemical carcinogenesis, and that this phenomenon probably plays a role in cancer development.

Bromodeoxyuridine induces integrin expression at transcriptional (alpha2 subunit) and post-transcriptional (beta1 subunit) levels, and alters the adhesive properties of two human lung tumour cell lines

Integrins are a family of transmembrane glycoproteins that participate in a wide range of cellular events including proliferation, apoptosis and differentiation. Little is known about the mechanisms that control integrin subunit expression in epithelial cells, especially during lung cell differentiation. We have examined the effect of the differentiation-modulating agent, 5-bromo-2'-deoxyuridine (BrdU), on integrin expression in 2 human lung carcinoma cell lines, DLKP and A549. Treatment of both DLKP and A549 with 10 microM BrdU for 7 days resulted in increased expression of alpha2 and beta1 integrin subunit protein expression. Northern blot and RT-PCR analyses revealed progressively increasing levels of the alpha2 mRNA transcripts following BrdU treatment up to 21 days in both cell lines. However, no increase in beta1 integrin mRNA levels was observed in either cell, suggesting post-transcriptional regulation by BrdU. Treatment of HL-60, a leukaemic cell line, with BrdU up to 21 days resulted in no change in alpha2 or beta1 integrin subunit levels at either protein or mRNA levels suggesting that the change seen in the lung cell lines may be epithelial cell lineage-specific. BrdU has also been found to alter the adhesive properties of A549 and DLKP cells. Treated cells were found to adhere significantly faster to collagen type IV and laminin compared to untreated cells. The results presented here suggest that DLKP (and A549) may be useful cellular models to investigate the role of the alpha2beta1 integrin in lung epithelial cell differentiation.

Molecular biology of lung cancer: clinical implications

This review summarizes the rapidly expanding knowledge of the molecular pathogenesis of lung cancer. It is clear that respiratory epithelial cells require many genetic alterations to become invasive and metastatic cancer. Much more is to be learned, but with modern technology. Clinicians can detect "field cancerized" regions and preneoplastic and malignant cells, therefore offering the opportunity to intercede with biomarker-monitored prevention and early detection efforts. Such molecular screening and detection efforts will likely be coupled to advances in low-dose computed tomographic imaging, positron emission tomography scans, and other imaging modalities. Although this molecular marker approach has great potential, there is not yet a molecular marker validated in large prospective trials that has major independent predictive prognostic value. There is an urgent need for large, adequately powered, carefully designed prospective studies to identify clinically useful new biomarkers. Finally, new therapeutic strategies with genetic manipulation, small molecules, antibodies, vaccines, and, particularly, new drugs targeting specific biologic pathways found to be abnormal in lung provide for future optimism. Researchers need to define their individual value, especially when integrated with standard therapies.

Reduced expression of laminin alpha 3 and alpha 5 chains in non-small cell lung cancers

The basement membrane is considered to act as a barrier which hinders cancer cells from invading the surrounding stroma. In order to assess changes in essential components during neoplasia in the lung, we immunohistochemically studied distribution patterns of laminins alpha 3 and alpha 5 in 40 adenocarcinomas and 8 squamous cell carcinomas. The a 5 chain was generally preserved at the periphery, frequently disrupted in foci with alveolar collapse and absent in foci of fibroblastic proliferation within adenocarcinomas. Fragmentation and absence of laminin alpha 3 chain were more prominent than for alpha 5 chain. Laminin alpha 3 chain was partially fragmented or absent in peripheral areas of adenocarcinomas, being significantly different from alpha 5 chain. Non-small cell lung cancers with reduced alpha 5 chain showed a tendency for greater lymph node metastasis. In cultured normal air way epithelial cells, both laminin alpha 3 and alpha 5 chains were found to be expressed by northern analysis. Eleven of the twelve cultured lung cancer cell lines did not express alpha 3 chain and expression of alpha 5 chain was reduced in three. Quantitative RT-PCR analysis also demonstrated expression of laminin alpha 3 chain in adenocarcinoma tissues to be significantly lower than in normal lung tissues. These results suggest that expression of laminin alpha chains is often reduced in lung cancer cells and this might contribute to basement membrane fragmentation and subsequent proliferation of stromal elements, as well as play some role in the process of cancer cell invasion.

Cell biology of lymphatic metastasis. The potential role of c-erbB oncogene signalling

Lymphatic metastases are an important indicator of the malignancy of epithelial cancers. Empirical clinical observations associating specific genetic abnormalities with tumour progression, allied with basic laboratory investigations, are providing not only improved prognostic and diagnostic opportunities, but also a detailed understanding of the molecular machinery of metastasis. One such association--between the c-erbB oncogene family and metastasis--has proved particularly instructive. Functional links between over-expression (and occasionally mutational activation) of c-erbB-1 (EGFR) and c-erbB-2 and specific phenotypes of metastatic cells have been elucidated. Activated c-erbB oncogenes potentiate tumour cell adhesion to endothelial cells and upregulate VEGF, potentially facilitating angiogenesis and vascular invasion. In addition, cells over-expressing these oncogenes frequently show aberrant cell-cell and cell-matrix interactions, mediated by changes in integrin and cadherin function. Thirdly, both EGFR and c-erbB-2 signalling can significantly upregulate specific matrix metalloproteinases, key enzymes involved in angiogenesis and invasion. Finally, c-erbB receptors linked to the actin cytoskeleton and highly expressed on invadopodia, are thought to assist cell migration. Taken together, these observations suggest that such receptors can act as "master switches" in metastasis, whose activation co-ordinately controls events normally utilised in development, now subverted by the metastatic cell. As such, they represent ideal targets for therapeutic intervention.

Molecular pathogenesis of lung cancer

Lung cancer is the largest cancer killer of men and women in the united states. In addition to the progress made from antismoking primary prevention measures, new tools to help treat patients with lung cancer are emerging from the rapid advances in knowledge of the molecular pathogenesis of lung cancer. These tools include molecular and cellular biology and are starting to provide an insight into how the tumor cell, by altering oncogenes and tumor suppressor genes, achieves growth advantage, uncontrolled proliferation and metastatic behavior via disruption of key cell-cycle regulators and signal transduction cascades. Moreover, new knowledge is being developed in terms of the molecular definition of individual susceptibility to tobacco smoke carcinogens. These tools are being translated into clinical strategies to complement surgery, radiotherapy, and chemotherapy and also to assist in primary and secondary prevention efforts. This review summarizes current knowledge of the molecular pathogenesis of lung cancer. From this we know that respiratory epithelial cells require many genetic alterations to become invasive and metastatic cancer. We can detect cells with a few such changes in current and former smokers, offering the opportunity to intercede with a biomarker-monitored prevention and early detection effort. This will be coupled with new advances in computed tomography-based screening. Finally, because the molecular alterations are known, new mechanism-based therapies are being developed and brought to the clinic, including new drugs, vaccines, and gene therapy, which also must be integrated with standard therapies.

Cloning of differentially expressed genes in highly and low metastatic rat osteosarcomas by a modified cDNA-AFLP method

To identify differentially expressed genes between highly and low metastatic rat transplantable osteosarcomas, we applied a modified AFLP (amplified fragment length polymorphisms) method for cDNA subtraction. The specific point of our modification is selective amplification using suppression PCR technique after restriction enzyme cutting. Our cDNA-AFLP gave high reproducibility (about 95%) in mRNA patterns and enabled us to clone four dominantly expressed genes in a highly metastatic tumor line. Three showed homology with known genes, encoding Ki-67, a proliferation-associated effective marker of malignancy, type IV collagen alpha-3, a major component of basement membrane, and KIAA77 for which the function is unknown. Although one fragment showed no database homology, we revealed a derivation from the rat homologue of the Drosophila melanogaster diaphanous gene (Dia) by cloning of longer cDNA. Dia genes, known to affect actin filament formation, are downstream effectors of Rho small GTPase. The results suggest that alterations in the expression of cytoskeletal protein, basement membrane elements, and proliferative markers may be important for metastasis of osteosarcomas.

The expression of basic fibroblast growth factor (bFGF) in tumor-associated stromal cells and vessels is inversely correlated with non-small cell lung cancer progression

Tumor progression results from complex interactions between tumor and tumor-associated host tissue. Basic fibroblast growth factor (bFGF), via activation of its receptor, FGFR-1, has been postulated to be an important inducer of host stromal response and angiogenesis. To assess the putative role of tumor-associated stromal cells and vessels in tumor progression, we studied non-small cell lung cancer (NSCLC) from 84 patients, including 51 squamous cell carcinomas and 33 nonsquamous cell carcinomas, by immunohistochemical detection. bFGF and FGFR-1 immunoreactivity was observed in tumor and in tumor-associated stromal cells and vessels. The expression of bFGF and FGFR-1 in stromal cells was higher in squamous than in non-squamous cell carcinomas (respectively, P = .007 and P = .0004). We found that bFGF and FGFR-1 expression in tumor and tumor-associated stromal cells and vessels was directly correlated with host stromal response, as assessed by intratumoral extension of stroma, but not with angiogenic response, as assessed by microvessel count. Although FGFR-1 expression of tumor cells was directly correlated with T-stage (P = .03), bFGF expressions of tumor-associated stromal cells and vessels were inversely correlated with lymph node metastasis (respectively, P = .0001 and P = .0002) and advanced pathological stage (respectively, P = .03 and P = .01). These findings suggest that bFGF might mediate host stromal response in NSCLC and that the expression of bFGF in tumor-associated stromal cells and vessels might have an inhibitory role in NSCLC progression.

What can we learn from the phenomenon of preferential lymph node metastasis in carcinoma?

Lymph nodes are the most common and earliest site of malignancies arising in epithelia. However, the reason for this pattern of preferential metastasis is not clear. This article reviews features of the metastatic process and lymph node microenvironment which might potentiate lymph node metastases. There is intriguing evidence that preferential lymph node metastasis is due to (1) the efficiency of lymph nodes as filters of the tumor cells which arrive there, and (2) the probability that adhesive interactions, normally governing the generation of different T-cell immune responses, are responsible for this efficiency and may also promote invasion and proliferation of tumor cells in the lymph node. Manipulation of the cytokine environment in a lymph node draining a primary epithelial tumor may alter both the expression of cell adhesion molecules within the node and the subsequent metastatic ability of the tumor cells arriving at it.

Prognostic markers in pheochromocytoma

Clinical and histopathological features do not reliably distinguish between benign and malignant pheochromocytomas. Additional markers that might be useful prognostic indicators in the pathological assessment of these tumors are sought. Immunohistochemical expression of MIB-1, Bcl-2, cathepsin B, cathepsin D, basic fibroblast growth factor (bFGF), c-met, and type IV collagenase were studied on formalin-fixed tissue from 33 nonconsecutive cases of pheochromocytoma, selected on the basis of reliable long-term follow-up, to determine associations with malignancy. The study group included 33 patients, 19 men and 14 women, with a mean age of 45 years, including five cases of neurofibromatosis (NF), three familial, and one MEN IIb. Mean follow-up was 63.2 months. Ten patients were determined to have malignant pheochromocytomas by the presence of metastatic disease. Features found to be associated with malignancy included MIB-1 labeling index (5% vs 1%) (P = .0009), male gender (90% vs 43%) (P = .008), extra-adrenal location (40% vs 9%) (P = .03), tumor weight (481 g vs 124 g) (P = .05), and young age (38 years vs 49 years) (P = .05). None of the five cases with NF were malignant (P = .04). S-100 positivity showed a significant (P = .02) but nonlinear association with benign tumors. Absent S-100 correlated with greater tumor weight. Malignancy was not associated with right versus left side or bilaterality, although bilateral tumors were smaller. C-met, bFGF, cathepsin B, cathepsin D, and collagenase were strongly expressed in most tumors and were not predictive of outcome, nor was bcl-2, which was variably expressed. Using multiple logistic regression with malignancy as the dependent variable, MIB-1 continued to show a significant association with malignancy (P = .005) independent of any association with sex, age, or extra-adrenal location. Using a cutoff value of MIB-1 labeling of greater than 3% yielded a specificity of 100% and a sensitivity of 50% in predicting malignancy.

The biochemistry of cancer dissemination

The progression of a tumor cell from one of benign delimited proliferation to invasive and metastatic growth is the major cause of poor clinical outcome of cancer patients. Recent research has revealed that this complex process requires many components for successful dissemination and growth of the tumor cell at secondary sites. These include angiogenesis, enhanced extracellular matrix degradation via tumor and host-secreted proteases, tumor cell migration, and modulation of tumor cell adhesion. Each individual component is multifaceted and is discussed within this review with respect to historical and recent findings. The identification of components and their interrelationship have yielded new therapeutic targets leading to the development of agents that may prove effective in the treatment of cancer and its metastatic progression.