A clinicopathological study of the expression of extracellular matrix components in urothelial carcinoma

Laminin-5, Fibronectin, and Type IV Collagen as Potential Biomarkers of Brain Glioma Malignancy

The presented work is based on the quantification of LN-5, FN, and COL IV in blood plasma as potential biomarkers in patients diagnosed with glioma in grades G1 to G4. The obtained concentration results were compared with the protein content in the control group, which consisted of smokers of different ages. The obtained results were statistically analysed and interpreted based on the available clinical description. Quantitative determinations of LN-5, FN, and COL IV were performed with the use of SPRi biosensors specific to the tested proteins. Comparing groups K and G4, as well as G2 and G4, statistically significant relationships between changes in the concentration of individual proteins, were observed. The analysis showed significant correlations between FN and LN-5, between FN and COL IV, and between LN-5 and COL IV. There was a moderate positive correlation between individual proteins and the age of the patient. The ROC analysis distinguished patients with advanced disease from the control group. The results of the research show that LN-5, FN, and COL IV are effective biomarkers of brain glioma that may be helpful in non-invasive diagnosis and determining the grade of the disease.

Collagen Remodeling along Cancer Progression Providing a Novel Opportunity for Cancer Diagnosis and Treatment

The extracellular matrix (ECM) is a significant factor in cancer progression. Collagens, as the main component of the ECM, are greatly remodeled alongside cancer development. More and more studies have confirmed that collagens changed from a barrier to providing assistance in cancer development. In this course, collagens cause remodeling alongside cancer progression, which in turn, promotes cancer development. The interaction between collagens and tumor cells is complex with biochemical and mechanical signals intervention through activating diverse signal pathways. As the mechanism gradually clears, it becomes a new target to find opportunities to diagnose and treat cancer. In this review, we investigated the process of collagen remodeling in cancer progression and discussed the interaction between collagens and cancer cells. Several typical effects associated with collagens were highlighted in the review, such as fibrillation in precancerous lesions, enhancing ECM stiffness, promoting angiogenesis, and guiding invasion. Then, the values of cancer diagnosis and prognosis were focused on. It is worth noting that several generated fragments in serum were reported to be able to be biomarkers for cancer diagnosis and prognosis, which is beneficial for clinic detection. At a glance, a variety of reported biomarkers were summarized. Many collagen-associated targets and drugs have been reported for cancer treatment in recent years. The new targets and related drugs were discussed in the review. The mass data were collected and classified by mechanism. Overall, the interaction of collagens and tumor cells is complicated, in which the mechanisms are not completely clear. A lot of collagen-associated biomarkers are excavated for cancer diagnosis. However, new therapeutic targets and related drugs are almost in clinical trials, with merely a few in clinical applications. So, more efforts are needed in collagens-associated studies and drug development for cancer research and treatment.

The dynamic roles of the bladder tumour microenvironment

Bladder cancer is a prevalent but currently understudied cancer type and patient outcomes are poor when it progresses to the muscle-invasive stage. Current research in bladder cancer focuses on the genetic and epigenetic alterations occurring within the urothelial cell compartment; however, the stromal compartment receives less attention. Dynamic changes and intercellular communications occur in the tumour microenvironment (TME) of the bladder - a new concept and niche that we designate as the bladder TME (bTME) - during tumour evolution, metastatic progression and in the context of therapeutic response. Collagens and their cognate receptors, the discoidin domain receptors, have a role in various steps of the metastatic cascade and in immune checkpoint resistance. Furthermore, the presence of another TME niche, the metastatic TME (met-TME), is a novel concept that could support divergent progression of metastatic colonization in different organs, resulting in distant metastases with distinct characteristics and genetics from the primary tumour. The stroma has divergent roles in mediating therapeutic response to BCG immunotherapy and immune checkpoint inhibitors, as well as conventional chemotherapy or trimodality therapy (that is, maximal transurethral resection of bladder tumour, chemotherapy and radiotherapy). The local bTME and distant met-TME are currently conceptually and therapeutically unexploited niches that should be actively investigated. New biological insights from these TMEs will enable rational design of strategies that co-target the tumour and stroma, which are expected to improve the outcomes of patients with advanced bladder cancer.

Fibronectin urothelial gene expression as a new reliable biomarker for early detection of local toxicity secondary to adjuvant intravesical therapy for non-muscle invasive bladder cancer

Background:

A marker of urothelial damage could be helpful for early detection and monitoring of local toxicity due to intravesical therapy for non-muscle invasive bladder cancer (NMIBC). The aim of the study was to investigate the correlation between fibronectin (FN) gene expression in bladder washings and local toxicity secondary to adjuvant intravesical therapy.

Materials and methods:

Patients undergoing adjuvant intravesical therapy for NMIBC and age-matched healthy patients were enrolled. Real time polymerase chain reaction was performed to analyze FN expression in bladder washings. Local toxicity was classified as: 0–1 mild (no medical therapy), 2 moderate (medical therapy and/or instillation postponed), 3 severe (discontinuation of therapy).

Results:

Seventy-two patients and 21 controls entered the study. A useful pellet was obtained in 58 patients and 18 controls. Intravesical Bacillus Calmette–Guerin (BCG), Epirubicin and Mitomycin C was offered to 69%, 13.8% and 17.2% of patients respectively. Compared with healthy controls (FN = 1.0 fold), overall median FN expression before adjuvant intravesical therapy was 1.73 fold [interquartile range (IQR) 0.8–2.3], while during therapy median FN expression increased to 3.41 (IQR: 1.6–6.1) fold. Considering 40 intermediate and high-risk patients undergoing intravesical BCG, median FN expression before adjuvant treatment was 1.92 [(IQR: 1.0–2.7) fold, increasing up to 4.1 (IQR: 1.9–6.6) during therapy. In more detail, FN increased during BCG therapy, showing a median expression of 4.22 (IQR: 2.2–5.5) and 6.16 (IQR: 2.6–8.7) fold in presence of grade 2 and 3 toxicity respectively, while remaining more or less stable in asymptomatic patients. After receiver operating characteristic curve analysis, FN value of 3.6 fold resulted, corresponding to 75% sensitivity and 69% specificity to predict grade 2–3 toxicity events (area under the curve 0.74, 95% confidence interval 0.63–0.85, p = 0.001).

Conclusion:

Our study validated the correlation between FN expression and urothelial damage. BCG seems to induce a urothelial activation with FN overexpression during adjuvant intravesical therapy. Grade of toxicity was related to FN expression.

DPP4/CD26 overexpression in urothelial carcinoma confers an independent prognostic impact and correlates with intrinsic biological aggressiveness

Urothelial carcinoma (UC) is common cancer worldwide. The molecular aberrations regarding tumor progression remain unclear. Pericellular proteolysis is crucial in tumorigenesis, but its significance is unexplored in UC. By data mining the datasets in Gene Expression Omnibus, specifically focus on the proteolysis pathway, and followed by a preliminary validation in a pilot batch of tumor samples, we identified that the upregulation of dipeptidyl peptidase 4 (DPP4) was most significantly associated with clinical aggressiveness of UCs. Quantitative RT-PCR confirmed upregulation of DPP4 mRNA in advanced stage UCs. The clinical significance of DPP4 expression was validated in our large cohort consists of 635 UCs from upper urinary tract and urinary bladder. Univariate and multivariate analyses show that DPP4 is an independent prognosticatory biomarker for disease-specific survival and metastasis-free survival. Comparing the DPP4 expression level of three urothelial cell lines with normal urothelial cells, J82 and RTCC-1 showed a significantly increased in transcript and protein expression. DPP4 knockdown as conducted by using short-hairpin RNA resulted in a significantly decreased cell viability, proliferation, migration, and invasion in J82 and RTCC-1 cells. These findings implicate that DPP4 plays a role in the aggressiveness of UCs, and can serve as a novel prognostic marker and therapeutic target.

Desmoplastic Pattern at the Tumor Front Defines Poor-prognosis Subtypes of Colorectal Cancer

Although recent findings of cancer biology research indicate that prognostic power arises from genes expressed by stromal cells rather than epithelial cells, desmoplastic reaction (DR) has not been completely examined as a prognostic marker for colorectal cancer. A pathologic review of 821 stage II and III patients who underwent R0 resection for colorectal cancer at 4 independent institutions was conducted. DR was classified as mature, intermediate, or immature based on the existence of hyalinized keloid-like collagen and myxoid stroma at the extramural desmoplastic front. Totally, 325, 282, and 214 patients were classified as having mature, intermediate, and immature DR, respectively. DR significantly influenced the recurrence rate in the liver, lung, and peritoneum (P≤0.0001 to 0.01). Five-year relapse-free survival (RFS) rate was the highest in the mature group (85.7%), followed by the intermediate (77.3%) and immature (50.4%) groups. A significant adverse impact of immature stroma on RFS was observed in subset analyses of the 4 institutions. Multivariate analysis revealed that DR, along with T and N stages, is an independent prognostic factor. On the basis of Harrell's concordance index, the prognostic power of DR categorization (0.67) in stratifying RFS was greater than any other conventional prognostic factors, including TNM (0.64), N (0.62) and T stages (0.59), venous invasion (0.59), and tumor grade (0.54). Characterizing DR based on the histologic products of activated fibroblasts is valuable for evaluating prognostic outcomes. To our knowledge, this is the first study reporting a greater prognostic power of histology of the fibrotic stroma than that of tumor factors.

Tenascin-C and fibronectin expression divide early stage tongue cancer into low- and high-risk groups

Background:

Oral tongue squamous cell carcinoma (OTSCC) metastasises early, especially to regional lymph nodes. There is an ongoing debate on which early stage (T1-T2N0) patients should be treated with elective neck dissection. We need prognosticators for early stage tongue cancer.

Methods:

Mice immunisation with human mesenchymal stromal cells resulted in production of antibodies against tenascin-C (TNC) and fibronectin (FN), which were used to stain 178 (98 early stage), oral tongue squamous cell carcinoma samples. Tenascin-C and FN expression in the stroma (negative, moderate or abundant) and tumour cells (negative or positive) were assessed. Similar staining was obtained using corresponding commercial antibodies.

Results:

Expression of TNC and FN in the stroma, but not in the tumour cells, proved to be excellent prognosticators both in all stages and in early stage cases. Among early stages, when stromal TNC was negative, the 5-year survival rate was 88%. Correspondingly, when FN was negative, no cancer deaths were observed. Five-year survival rates for abundant expression of TNC and FN were 43% and 25%, respectively.

Conclusions:

Stromal TNC and, especially, FN expressions differentiate patients into low- and high-risk groups. Surgery alone of early stage primary tumours might be adequate when stromal FN is negative. Aggressive treatments should be considered when both TNC and FN are abundant.

Mitogen-activated protein kinase signaling causes malignant melanoma cells to differentially alter extracellular matrix biosynthesis to promote cell survival

BACKGROUND

Intrinsic and acquired resistance to drug therapies remains a challenge for malignant melanoma patients. Intratumoral heterogeneities within the tumor microenvironment contribute additional complexity to the determinants of drug efficacy and acquired resistance.

METHODS

We use 3D biomimetic platforms to understand dynamics in extracellular matrix (ECM) biogenesis following pharmaceutical intervention against mitogen-activated protein kinases (MAPK) signaling. We further determined temporal evolution of secreted ECM components by isogenic melanoma cell clones.

RESULTS

We found that the cell clones differentially secrete and assemble a myriad of ECM molecules into dense fibrillar and globular networks. We show that cells can modulate their ECM biosynthesis in response to external insults. Fibronectin (FN) is one of the key architectural components, modulating the efficacy of a broad spectrum of drug therapies. Stable cell lines engineered to secrete minimal levels of FN showed a concomitant increase in secretion of Tenascin-C and became sensitive to BRAF(V600E) and ERK inhibition as clonally- derived 3D tumor aggregates. These cells failed to assemble exogenous FN despite maintaining the integrin machinery to facilitate cell- ECM cross-talk. We determined that only clones that increased FN production via p38 MAPK and β1 integrin survived drug treatment.

CONCLUSIONS

These data suggest that tumor cells engineer drug resistance by altering their ECM biosynthesis. Therefore, drug treatment may induce ECM biosynthesis, contributing to de novo resistance.

Urinary oncofetal ED-A fibronectin correlates with poor prognosis in patients with bladder cancer

The extracellular matrix protein fibronectin (FN) contributes to the structural integrity of tissues as well as the adhesive and migratory functions of cells. While FN is abundantly expressed in adult tissues, the expression of several alternatively spliced FN isoforms is restricted to embryonic development, tissue remodeling and cancer. These FN isoforms, designated ED-A and ED-B, are frequently expressed by cancer cells, tumor-associated fibroblasts and newly forming blood vessels. Using a highly sensitive collagen-based indirect ELISA, we evaluated the correlation of urinary ED-A and ED-B at time of cystectomy with overall survival in patients with high-grade bladder cancer (BCa). Detectable levels of total FN as well as ED-A and ED-B were found in urine from 85, 73 and 51 % of BCa patients, respectively. The presence of urinary ED-A was a significant independent predictor of 2-year overall survival (OS) after adjusting for age, tumor stage, lymph node stage, and urinary creatinine by multivariable Logistic Regression (p = 0.029, OR = 4.26, 95 % CI 1.16-15.71) and improved accuracy by 3.6 %. Furthermore, detection of ED-A in the urine was a significant discriminator of survival specifically in BCa patients with negative lymph node status (Log-Rank, p = 0.006; HR = 5.78, 95 % CI 1.39-24.13). Lastly, multivariable Cox proportional hazards analysis revealed that urinary ED-A was an independent prognostic indicator of 5-year OS rate for patients with BCa (p = 0.04, HR = 2.20, 95 % CI 1.04-4.69). Together, these data suggest that cancer-derived, alternatively spliced FN isoforms can act as prognostic indicators and that additional studies are warranted to assess the clinical utility of ED-A in BCa.

Immunohistochemical Analysis of Collagen IV and Laminin Expression in Spontaneous Melanoma Regression in the Melanoma-Bearing Libechov Minipig

Spontaneous regression (SR) of human melanoma is a rare, well-documented phenomenon that is not still fully understood. Its detailed study cannot be performed in patients due to ethical reasons. Using the Melanoma-bearing Libechov Minipig (MeLiM) animals of various ages (from 3 weeks to 8 months) we implemented a long-term monitoring of melanoma growth and SR. We focused on immunohistochemical detection of two important extracellular matrix proteins, collagen IV and laminin, which are associated with cancer. We showed that SR of melanoma is a highly dynamic process. The expression of collagen IV and laminin correlated with changes in population of melanoma cells. Tumours of 3-week-old animals consisted primarily of melanoma cells with a granular expression of collagen IV and laminin around them. Thereafter, melanoma cells were gradually destroyed and tumour tissue was rebuilt into the connective tissue. Collagen IV expression slightly increased in tumours of 10-week-old pigs showing extracellular fibrous appearance. In tumours of older animals, areas lacking melanoma cells demonstrated a low expression and areas still containing melanoma cells a high expression of both proteins. We considered the age of 10 weeks as a turning point in the transition between tumour growth and SR of the MeLiM melanoma.

Tenascin-C and carcinoma cell invasion in oral and urinary bladder cancer

Carcinoma invasion is a complex process regulated by genetic and epigenetic factors as well. A relevant supportive condition for cancer cell migration is the reorganization of the extracellular matrix (ECM), which is realized in an orchestrated multicellular manner including carcinoma cells and stromal fibroblasts. An important key player in the process of ECM reorganization is Tenascin-C (Tn-C). The molecule occurs as different isoforms generated by alternative splicing and de novo glycosylation. Large variants of Tn-C are abundantly re-expressed in the invasive front of many carcinoma types. A special role for initiating migration and accompanied epithelial to mesenchymal transition has been suggested. Here, we review the current knowledge concerning the tumor biological importance of Tn-C, the synthesis and alternative splicing during the invasive process in general, and give an overview on the impact of Tn-C in urothelial carcinoma of the urinary bladder (UBC) and oral squamous cell carcinoma (OSCC).

Histologic categorization of desmoplastic reaction: its relevance to the colorectal cancer microenvironment and prognosis

BACKGROUND

Although the essential roles of stromata in tumor development have been recognized, the morphologic classification of desmoplastic reaction (DR) in colorectal cancer (CRC) is unclear.

METHODS

In this study, DRs were histologically classified into three patterns based on the products of activated fibroblasts (i.e., keloid-like collagen and myxoid stroma). The prognostic impact of DRs was evaluated in two independent cohorts of stages 2 and 3 CRC patients: cohort 1 (880 patients) and cohort 2 (474 patients). The association of DR and the local environment was investigated immunohistochemically.

RESULTS

In cohort 1, mature DR was shown by 413 patients, intermediate DR by 275 patients, and immature DR by 192 patients. Categorization of DR was significantly associated with tumor location, pT and pN stages, tumor differentiation, venous invasion, tumor budding, and Crohn's-like lymphoid reaction (P ≤ 0.0001-0.008). Immature DR was relevant to the high incidence of recurrence in the liver, lung, lymph nodes, peritoneum, and locoregional areas (P ≤ 0.0001-0.002). The 5-year disease-free survival rate was highest in the mature group (87 %), followed by the intermediate group (72 %) and the immature group (49 % (P < 0.0001). In the multivariate analysis, DR showed an impact on survival outcome independent of conventional prognostic factors, including pT and pN stages. These results were similarly observed in cohort 2. Immature DR was associated with normal MutL homologue 1 (MLH1)/MutS homologue 2 (MSH2) immunoreactivity, a smaller number of infiltrating CD8(+) T cells and tumor-associated macrophages, a decreased microvessel count, and positive expression of tenascin-C and fibronectin.

CONCLUSION

The proposed histologic DR categorization directly reflects tumor behavior in a modulating stromal environment and could provide valuable prognostic information for CRC patients.

Far from resolved: stromal cell-based iTRAQ research of muscle-invasive bladder cancer regarding heterogeneity

The aim of the present study was to globally characterize the cancer stroma expression profile of muscle-invasive bladder cancer in different metastatic risk groups and to discuss the decisive role of biological pathway change in cancer heterogeneity. Laser capture microdissection was employed to harvest purified muscle-invasive bladder cancer stromal cells derived from 30 clinical samples deriving from 3 different metastatic risk groups. Isobaric tags for relative and absolute quantitation (iTRAQ) and two-dimensional liquid chromatography tandem mass spectrometry (2D LC-MS/MS) were used to identify the differentially expressed proteins. Subsequently, the differentially expressed proteins were further analyzed by bioinformatics tools. After completing the above tasks, the proteins of interest were further compared with the published litterature. We identified 1,049 differentially expressed proteins by paired comparison (high risk vs. median, low risk and normal groups; median risk vs. low risk and normal groups, low risk vs. normal group; a total of 6 comparisons). A total of 510,549,548 proteins as significantly altered (ratio fold-change≥1.5 or ≤0.667 between the metastatic potential risk group and the normal group) were presented in the low/median/high metastatic risk group, respectively. Pathway analysis revealed that the differentially expressed proteins were mainly located in the Kyoto Encyclopedia of Genes and Genomes pathways, including focal adhesion pathway, systemic lupus erythematosus pathway and ECM-receptor interaction pathway. In addition, several proteins such as EXOC4, MYH10 and MMP-9 may serve as candidate biomarkers of muscle-invasive bladder cancer. Our study confirmed that stromal cells, an important part of the cancer tissue, are pivotal for regulating the heterogeneity of cancer. Common changes in biological pathways determined the malignant phenotype of muscle-invasive bladder cancer, and biomarker discovery should take into account both neoplastic cells and their corresponding stromata.

Urine tenascin‑C is an independent risk factor for bladder cancer patients

Urine biomarkers offer a non‑invasive method of detecting bladder cancer, monitoring disease progression and predicting disease recurrence and therapeutic treatment efficacy. Tenascin‑C (TN‑C), as a component of the extracellular matrix, is vital in the progression of bladder cancer. However, there is little to report with regard to urine TN‑C and its correlation with bladder cancer grade, stage, recurrence and prognosis. In the present study, 66 samples of voided urine from patients with bladder cancer and 42 samples from volunteers were obtained. The urine TN‑C concentration was determined using an ELISA assay. The correlation between the urine TN‑C concentration and the tumor grade, stage and time from bladder cancer diagnosis to recurrence was analyzed by a rank correlation analysis. Multivariate Cox proportional hazards regression was used for finding the main life‑threatening factors among age, gender, tumor grade, stage, relapse and the urine TN‑C concentration. At the end, the Kaplan‑Meier method was used to evaluate the survival rate affected by urine TN‑C as a single factor. The results indicated that the urine TN‑C concentration in the bladder cancer patients was higher compared with the healthy control volunteers (22.5 times higher). Among all the patients, urine TN‑C concentration had a positive correlation with the bladder cancer grade and stage, with correlation coefficients of 0.905 and 0.308, respectively; however, this correlation was negative between urine TN‑C concentration and the time from bladder cancer diagnosis to recurrence. Moreover, the multivariate Cox proportional hazards model analysis indicated that urine TN‑C, like tumor grade and recurrence, may be an independent risk factor for bladder cancer patient survival. However, it is noteworthy that inflammation may affect the concentration of urine TN‑C. The results of the present study indicate that urine TN‑C may be used as a biomarker for monitoring the recurrence of bladder cancer in patients and for predicting its prognosis. However, inflammation of the urinary tract should be excluded first.

Cetuximab attenuates its cytotoxic and radiosensitizing potential by inducing fibronectin biosynthesis

Inherent and acquired resistance to targeted therapeutics continues to emerge as a major clinical obstacle. For example, resistance to EGF receptor targeting occurs commonly, more so than was expected, on the basis of preclinical work. Given emerging evidence that cancer cell-substrate interactions are important determinants of therapeutic sensitivity, we examined the impact of cell-fibronectin interactions on the efficacy of the EGF receptor antibody cetuximab, which is used widely for lung cancer treatment. Our results revealed the potential for cell-fibronectin interactions to induce radioresistance of human non-small cell lung cancer cells. Cell adhesion to fibronectin enhanced tumor cell radioresistance and attenuated the cytotoxic and radiosensitizing effects of cetuximab. Both in vitro and in vivo, we found that cetuximab treatment led to a remarkable induction of fibronectin biosynthesis. Mechanistic analyses revealed the induction was mediated by a p38-MAPK-ATF2 signaling pathway and that RNAi-mediated inhibition of fibronectin could elevate the cytotoxic and radiosensitizing potential of cetuximab. Taken together, our findings show how cell adhesion blunts cetuximab, which, by inducing fibronectin, generates a self-attenuating mechanism of drug resistance.

CLT1 targets bladder cancer through integrin α5β1 and CLIC3

High-grade non-muscle-invasive bladder cancer is commonly treated with Bacillus Calmette-Guérin, an immunotherapeutic that depends on fibronectin and tumor cell integrin α5β1 for internalization into bladder cancer cells. We previously showed that the anti-angiogenic peptide CLT1 forms cytotoxic complexes with fibronectin that are cooperatively internalized into proliferating endothelium through ligation of integrins and chloride intracellular channel 1. While CLT1 has no effect on mature, differentiated cells, we show here that CLT1 is highly cytotoxic for a panel of bladder tumor cell lines as well as a variety of cell lines derived from kidney, lung, breast, and prostate cancer. Paralleling our previous results, we found CLT1-induced tumor cell death to be increased in the presence of fibronectin, which mediated CLT1 internalization and subsequent autophagic cell death in a mechanism that depends on tumor cell integrin α5β1 and chloride intracellular channel 3 (CLIC3). This mechanistic link was further supported by our results showing upregulation of α5β1 and CLIC3 in CLT1-responsive tumor cell lines and colocalization with CLT1 in tumor tissues. Incubating tumor tissue from patients with bladder cancer with fluorescein-conjugated CLT1 resulted in a strong and specific fluorescence whereas normal bladder tissue remained negative. On the basis of its affinity for bladder tumor tissue and strong antitumor effects, we propose that CLT1 could be useful for targeting bladder cancer.

Pro-metastatic tumor–stroma interactions in breast cancer

The vast majority of breast cancer-related deaths are due to metastatic disease. Reciprocal and complex interactions between epithelial tumor cells and the various components of the tumor microenvironment influence tumor progression and metastases although the molecular mechanisms underlying these metastasis-promoting effects are not fully characterized. Identifying and understanding pathways of tumor–stroma cross-talk are likely to lead to the development of novel prognostic biomarkers for metastasis and strategies to prevent metastasis at its earliest stages, resulting in improved patient outcomes.

B domain containing Tenascin-C: a new urine marker for surveillance of patients with urothelial carcinoma of the urinary bladder?

BACKGROUND

ECM remodelling during tumorigenesis entails the re-occurrence of different Tn-C(L) splicing variants. In patients with urothelial carcinoma of the urinary bladder (UBC), B and C domain containing Tenascin-C (B(+) and C(+) Tn-C) urine levels were shown to be increased in case of muscle invasiveness. Thus, the present study was aimed at examining the ability of B(+) and C(+) Tn-C as potential urinary surveillance markers of UBC patients.

METHODS

Urine levels of B(+) and C(+) Tn-C were determined by ELISA in 35 UBC patients during a 2 year follow-up period after therapy and related to clinical diagnosis and histological stage in 4 defined groups representing typical courses of disease.

RESULTS

B(+) Tn-C levels showed significant differences between cases of tumour progression or regression. The urine levels of B(+) Tn-C could be used to discriminate between cases without tumour recurrence and such with tumour existence (cut-off value: 0.8 ng/ml) or between non-muscle invasive and muscle invasive tumour growth (cut-off value: 3.5 ng/ml).

CONCLUSIONS

Progression of UBC with time is accompanied by significant changes in urinary levels of B(+) Tn-C. Urinary B(+) Tn-C can therefore be suggested as a valuable urine surveillance marker in UBC follow-up care.

Therapeutic targeting of tumor-stroma interactions

INTRODUCTION

Cancers exist within a complex microenvironment populated by diverse cell types within a protein-rich extracellular matrix. It is becoming increasingly apparent that molecular interactions between epithelial cells and cells in the surrounding stroma promote growth, invasion and spread of the tumor itself and thus represents a crucial underlying driving force in tumorigenesis.

AREAS COVERED

This article reviews how key interactions between tumor epithelial cells and surrounding mesenchymal and immune cells can promote tumor progression and highlights molecular elements that might represent novel therapeutic targets.

EXPERT OPINION

The tumor microenvironment is increasingly being viewed as a potential therapeutic target with a number of strategies being developed to disrupt tumor-stroma interactions, in order to delay or circumvent tumor progression. Targeting elements of the tumor microenvironment, or signaling pathways in tumor cells activated as a consequence of stromal interactions, may prove a useful therapeutic strategy to prevent tumor development and progression. However, given the tumor cells' ability to circumvent various therapeutic agents when given as monotherapy, the success of these agents is likely to be seen when used in combination with existing treatments.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

B and C domain containing tenascin-C: urinary markers for invasiveness of urothelial carcinoma of the urinary bladder?

PURPOSE

Surveillance of urothelial carcinoma of the urinary bladder (UBC) patients with respect to tumour recurrence and invasiveness is crucial for therapy and prognosis. Therefore, evaluation of non-invasive methods to monitor tumour progression is of high clinical interest. The study was aimed at investigating urinary concentrations of tenascin-C splicing domains for their value as tumour surveillance markers.

METHODS

Urinary concentration of B and C domain containing tenascin-C (Tn-C) was analysed by ELISA technology in 104 UBC patients, 11 patients with cystitis and 15 healthy donors as control. The investigation was supplemented by Tn-C immunohistochemistry and Western blotting.

RESULTS

A statistically significant increase in urinary concentrations of both Tn-C B and C domain with tumour progression could be evidenced. A concordant tumour-associated enhanced protein deposition in the carcinoma stroma could be demonstrated by immunohistochemistry in invasive UBC. Western blotting reveals proteolytic fragmentation of urinary Tn-C.

CONCLUSIONS

In summary, detection of Tn-C splicing domains in urine is suggested as a marker for the surveillance of UBC recurrence and invasiveness.

[Transitional cell carcinoma of the bladder. Evaluation of plasma levels of cellular fibronectin as a stage-dependent marker]

Up to now markers for transitional cell carcinoma of the bladder (TCC) are missing. Fibronectin (FN) seems to play a key role in progression and invasion of malignant tumors. The aim of this study was to assess the value of cellular FN (cFN), a more specific subform of produced FN, in different stages of TCC.cFN was determined using a highly sensitive immunoassay which we developed. Blood samples were taken of 45 patients with the first diagnosis of TCC before undergoing TUR-B and 6 patients with metastatic TCC before chemotherapy; 70 patients with nonmalignant urological disorders served as a control group.Patients with TCC showed significantly elevated cFN plasma levels compared to controls (p<0.05). Patients with muscle-invasive disease (n=15) showed significantly higher cFN plasma levels compared to the group with superficial TCC. Patients with metastatic TCC showed the highest, but not significantly elevated cFN plasma levels compared to patients with muscle-invasive TCC.The elevated cFN plasma levels in TCC underline the important role of cFN for tumor progression and its potential role as a marker for TCC. Upcoming investigations are necessary to prove the value of the potential marker cFN during follow-up and its impact as a prognostic factor for recurrence and progression of TCC.

IIICS de novo glycosylated fibronectin as a marker for invasiveness in urothelial carcinoma of the urinary bladder (UBC)

PURPOSE

The urothelial carcinoma is the most frequent malignancy of the urinary bladder (UBC). The transition into invasive growth is accompanied by several histological changes including an oncofoetal reorganization of the extracellular matrix. Recently, the occurrence of oncofoetal fibronectin with an O-linked glycosylation in the IIICS region (oncf Fn) was shown to be present in urine from UBC patients and was recommended as a tumour marker. Until now there are no data available regarding the source and distribution of oncf Fn in UBC and its value for the assessment of invasiveness.

METHODS

oncf Fn was analysed in noninvasive and invasive UBC using immunohistochemistry and western blot. Additionally, the mRNA expression of the IIICS splicing region was evaluated by quantitative real time RT-PCR.

RESULTS

Immunohistochemical results reveal a highly significant correlation of oncf Fn to invasiveness. Papillary tumours regularly show no positivity. In western blot, invasive UBC show a strongly increased amount of the 250 kDa oncf Fn. Additionally, several smaller bands could be shown suggesting a proteolytic processing of Fn. The mRNA of the IIICS region shows a 21.5-fold increase in invasive UBC compared with noninvasive carcinomas.

CONCLUSIONS

In summary, immunohistochemistry of oncf Fn is a valuable histological marker for invasiveness of urothelial carcinoma of the urinary bladder. The restricted and invasion-associated tissue distribution of immunoreactivity enables to monitor the recurrence of invasive UBC by a quantitative evaluation of IIICS O-linked glycosylated Fn in urine.

Tenascin-C expression and its prognostic significance in colorectal cancer

OBJECTIVE

The extracellular matrix glycoprotein tenascin-C has been proposed as a tumor marker with prognostic significance in many cancer forms, but in colorectal cancer, reported results have been controversial. The aim of this study was to evaluate the prognostic value of immunohistochemical tenascin-C expression in a series of 231 patients with colorectal cancer.

METHODS

Paraffin-embedded formalin-fixed specimens were stained with a tenascin-C-specific monoclonal antibody, and the stromal staining intensity and pattern were analyzed.

RESULTS

Tenascin-C immunoreactivity was observed in all 231 specimens, with a pattern of staining that was diffuse and interstitial. The staining was occasional in 39 (17%), moderate in 106 (46%) and strong in 86 specimens (37%). There was no statistically significant association between tenascin-C immunoreactivity and any of the other clinicopathological variables. The cumulative 5-year survival rates of patients with occasional and weak staining were similar (56.8 and 54.9%, respectively), while the patients with strong tenascin-C staining had a lower survival rate (46.1%). This difference in survival was not significant (p = 0.23). The staining pattern and distribution can be viewed from digitized representative microscope slides (virtual slides) at http://www.webmicroscope.net/supplements/tenascin.

CONCLUSIONS

Our results indicate that immunohistochemical expression of tenascin-C is not of prognostic significance in colorectal cancer.

The role of structural extracellular matrix proteins in urothelial bladder cancer (review)

The extracellular matrix (ECM) plays a key role in the modulation of cancer cell invasion. In urothelial carcinoma of the bladder (UC) the role of ECM proteins has been widely studied. The mechanisms, which are involved in the development of invasion, progression and generalization, are complex, depending on the interaction of ECM proteins with each other as well as with cancer cells. The following review will focus on the pathogenetic role and prognostic value of structural proteins, such as laminins, collagens, fibronectin (FN), tenascin (Tn-C) and thrombospondin 1 (TSP1) in UC. In addition, the role of integrins mediating the interaction of ECM molecules and cancer cells will be addressed, since integrin-mediated FN, Tn-C and TSP1 interactions seem to play an important role during tumor cell invasion and angiogenesis.

Notes on the tumorigenesis of bladder urothelioma

Bladder urothelioma is a common and increasingly frequent tumor, which most of the times involves initially the bladder mucosa only. Urotheliomas can be superficial, with low malignant potential despite their high relapsing activity, and highly aggressive ab initio. A series of events are known to influence urothelioma genesis, growth, cell interactions and apoptosis. Some initial constant changes involving chromosome 9 occur in the urothelium, whereas the 20–30 % of cases also show an alteration on chromosome 20, which is likely to result in marked biological aggressiveness. The transformation of normal urothelium into hyperplastic, and then neoplastic, urothelium is secondary to a wide range of molecular changes, which are here summarized.

Epigenetic reversion of breast carcinoma phenotype is accompanied by changes in DNA sequestration as measured by AluI restriction enzyme

The importance of microenvironment and context in regulation of tissue-specific genes is well established. DNA exposure to or the sequestration from nucleases detects differences in higher order chromatin structure in intact cells without disturbing cellular or tissue architecture. To investigate the relationship between chromatin organization and tumor phenotype, we used an established three-dimensional assay in which normal and malignant human breast cells can be easily distinguished by the morphology of the structures they make (acinus-like versus tumor-like, respectively). We show that these phenotypes can be distinguished also by sensitivity to AluI digestion in which the malignant cells resist digestion relative to nonmalignant cells. Treatment of T4-2 breast cancer cells in three-dimensional culture with cAMP analogs or a phosphatidylinositol 3-kinase inhibitor not only reverted their phenotype from nonpolar to polar acinar-like structures but also enhanced chromatin sensitivity to AluI. By using different cAMP analogs, we show that cAMP-induced phenotypic reversion, polarization, and shift in DNA organization act through a cAMP-dependent protein-kinase A-coupled signaling pathway. Importantly, inhibitory antibody to fibronectin produced the same effect. These experiments underscore the concept that modifying the tumor microenvironment can alter the organization of tumor cells and demonstrate that architecture and global chromatin organization are coupled and highly plastic.

Hypoxia-inducible factors HIF-1alpha and HIF-2alpha expression in bladder cancer and their associations with other angiogenesis-related proteins

Hypoxia-inducible factors (HIF-1alpha and HIF-2alpha) are closely related protein complexes that activate transcription of target genes in response to hypoxia. The immunohistochemical expression of these two proteins was investigated in 144 bladder cancer tissue samples and correlated with standard clinicopathological features, in order to elucidate their prognostic significance. We also evaluated their possible associations with other angiogenesis related markers such as microvessel density (MVD), vascular endothelial growth factor, thymidine phosphorylase, tenascin, fibronectin, p53 and bcl-2 to further clarify their implication in tumor stroma vascularization. Nuclear HIF-1alpha expression in tumor cells was detected in 57.1% of the cases. A trend of correlation of this expression with poorly differentiated tumors was observed. In addition, HIF-1alpha expression was positively correlated with stromal cells thymidine phosphorylase expression. Tumors that were progressed in muscle-infiltrating disease showed a higher HIF-1alpha expression. A higher HIF-1alpha expression was also observed in tumors with an in situ component. In tumor cells, low HIF-2alpha expression was observed in 6.3%, moderate in 31.9% and high in 61.8% of the cases. A trend of correlation of this expression with MVD was observed. In addition, HIF-2alpha expression was positively correlated with thymidine phosphorylase and fibronectin expression. A lower HIF-2alpha expression was detected in tumors that recurred earlier in univariate methods of analysis. HIF-2alpha was expressed in tumor stroma associated cells in 53.5% of specimens and was correlated with advance tumor stage, thymidine phosphorylase and tenascin expression. There was no statistically significant difference in the expression of both HIF-1alpha and HIF-2alpha between primary and recurrent tumors. In multivariate analysis including T stage, T grade, multifocality and T size, both HIF-1alpha and HIF-2alpha expression were not considered dependent in the prediction of recurrence or progression. In conclusion, the results of the present study indicate that HIF-1alpha and HIF-2alpha expression may help to predict recurrence or progression to muscle invasive disease but not as independent prognostic factors. In addition, the expression of HIF-1alpha and HIF-2alpha, appear to play a role in bladder cancer, vascularization possibly and in cooperation with other angiogenic factors.

Stem cells and cancer: an intimate relationship

Tumour-wide 'omics' approaches have long held sway as the approach to identifying useful therapeutic targets. This view is changing with the realization that many, if not all, cancers contain a minority population of self-renewing stem cells, the cancer stem cells, which are entirely responsible for sustaining the tumour as well as giving rise to proliferating but progressively differentiating cells that are responsible for much of the cellular heterogeneity that is so familiar to histopathologists. Moreover, although many tumours probably have their origins in normal stem cells, persuasive evidence from the haematopoietic system suggests that genetic alterations in more committed progenitor cells can reactivate the self-renewal machinery, resulting in a further source of cancer stem cells. Thus, the bulk of the tumour is not the problem, and so the identification of cancer stem cells and the factors that regulate their behaviour are likely to have an enormous bearing on the way that we treat neoplastic disease in the future.

Differential expression of tenascin-C splicing domains in urothelial carcinomas of the urinary bladder

PURPOSE

Through alternative splicing of the extracellular matrix protein tenascin-C (Tn-C) primary transcript nine type III homology repeats can be independently included or omitted. Large, low spliced Tn-C variants (Tn-C(L)) are preferentially expressed during tissue remodelling processes like tumour invasion to modulate cell migration. The study was aimed to evaluate the differential expression of Tn-C splicing domains in urinary bladder carcinoma with respect to the invasive behaviour.

METHODS

The deposition and synthesis of the Tn-C splicing domains A1-D was analysed in 34 urinary bladder carcinomas by semiquantitative immunohistochemistry using domain specific antibodies and by RT-PCR. Results were correlated to tumour stage and grade.

RESULTS

There is a significant increase of Tn-C(L) with higher tumour stage and grade. Immunohistochemistry revealed a more restricted distribution pattern of A1, B, and/or D domain containing Tn-C variants to invasive tumours, tumour vessels, and to destructed muscle. The mRNA expression patterns of the domains A1-A3 are similar among the different carcinomas. Stronger differences exist in the region from the B to D domain. In general, the domains AD1/C are rarely expressed. AD1 domain expression seems to be connected with compact invasion pattern.

CONCLUSION

In urinary bladder carcinoma a differential expression of Tn-C splicing variants exists in dependence of tumour type, vascularization, and invasive behaviour. Therefore, the detection of different Tn-C splicing domains could be useful for assessment of muscle invasion, tumour surveillance, as well as target structures for antibody based tumour detection and therapy.

Thrombospondin-1 expression in urothelial carcinoma: prognostic significance and association with p53 alterations, tumour angiogenesis and extracellular matrix components

Background

Thrombospondin-1 (TSP-1) is an extracellular matrix component glycoprotein, which is known to be a potent inhibitor of angiogenesis and may be important in cancer invasiveness. We examined the TSP-1 expression in correlation with conventional clinicopathological parameters to clarify its prognostic significance in bladder cancer. In addition, the possible correlation of TSP-1 expression with microvessel count, VEGF expression, p53 expression as well as with the expression of the extracellular matrix components was studied to explore its implication in vascularization and tumour stroma remodeling.

Methods

The immunohistochemical expression of TSP-1 in tumour cells and in the tumour stroma was studied in 148 formalin-fixed paraffin-embedded urothelial cell carcinoma tissue samples.

Results

TSP-1 was detected in perivascular tissue, at the epithelial-stromal junction, in the stroma and in tumour cells in the majority of the cases. In tumour cells, low TSP-1 expression was observed in 43% of the cases, moderate and high in 7%, while 50% showed absence of TSP expression. A higher TSP-1 immunoreactivity in well and moderately differentiated tumours compared to poorly differentiated was noted. PT₁ tumours showed decreased TSP-1 expression in comparison to pTa and pT_2–4 tumours. Increased tumour cell TSP-1 expression was related to increased microvessel density. In the tumour stroma, 37% of the cases showed small amount of TSP-1 expression, 7.5% moderate and high, while 55% of the cases showed absence of TSP-1 stromal immunoreactivity. Stromal TSP-1 expression was inversely correlated with tumour stage and tumour size. This expression was also positively correlated with microvessel density, VEGF expression and extracellular matrix components tenascin and fibronectin. Using univariate and multivariate analysis we didn't find any significant correlation of TSP-1 expression in superficial tumours in both tumour cells and tumour stroma in terns of the risk of recurrence and disease progression

Conclusion

Our data suggest that both tumour and stromal TSP-1 expression may play a role in tumour aggressiveness and angiogenesis. In addition, the correlation of stromal TSP-1 expression with extracellular matrix components fibronectin and tenascin indicate its possible implication in tumour stroma remodeling.

Stem cell plasticity and tumour formation

Stem cell plasticity refers to the ability of certain stem cells to switch lineage determination and generate unexpected cell types. This review applies largely to bone marrow cells (BMCs), which appear to contribute positively to the regeneration of several damaged non-haematopoietic tissues. This beneficial effect on regeneration may be a direct result of BMCs giving rise to organ parenchymal cells. Alternatively, it could be due to BMCs fusing with existing parenchymal cells, or providing paracrine growth factor support, or contributing to neovascularisation. In the context of oncology, BMC derivation of the tumour stroma and vasculature has profound biological and therapeutic implications, and there are several examples of carcinomas seemingly being derived from BMCs.