[Collagen type I expression in squamous cell carcinoma of the oral cavity]

Prognostic Value of Intratumoral Collagen Quantification in Canine Oral Melanomas

The majority of the melanocytic neoplasms are considered malignant and highly metastatic. However, a subset of the melanocytic tumors has a more favorable prognosis and the identification of precise prognostic markers for this neoplasm may be useful to guide treatment. The collagen architecture and density have been shown to correlate with tumor progression in human breast cancer and canine mast cell tumors. The purpose of the present study was to investigate the prognostic value of the intratumoral collagen index (ICI) as an indicator of postsurgical survival and its relation with other prognostic markers for canine oral melanomas (OMs). Twenty-two cases were tested for intratumoral collagen density using Masson's trichrome stain and morphometry. No differences were found between dogs regarding survival. The ICI was not correlated with proliferative activity or nuclear atypia. The results presented herein indicate that the quantity of intratumoral collagen in canine OMs is not an efficient indicator of postsurgical survival. Complementary studies about the expression and activity of enzymes that are capable of degrading extracellular matrix (ECM) components are necessary.

A quantitative and qualitative comparative analysis of collagen fibers to determine the role of connective tissue stroma in oral squamous cell carcinoma using special stains and polarized microscopy

Background:

Solid tumors such as oral squamous cell carcinoma (OSCC) are composed of malignant epithelial cells and the stroma in which these cells are dispersed. As the tumor progresses, the extracellular matrix undergoes dramatic morphological and architectural changes. Special stains make analysis easy and less erroneous by highlighting the area of interest and can be used to study these changes.

Aim:

The aim of the study was to analyze morphological changes in collagen fibers in various histological grades of OSCC using Masson's trichrome (MT) and Picrosirius red (PSR).

Study Design:

The study comprised 74 tissue samples, divided into two groups: Group I consisted of 63 cases of histologically proven OSCC (39 cases of well-differentiated squamous cell carcinoma [WDSCC], 17 moderately differentiated squamous cell carcinoma [MDSCC] and 7 poorly differentiated squamous cell carcinoma [PDSCC]) and Group II consisted of 11 cases of normal mucosa as controls.

Materials and Methods:

Sections were stained with hematoxylin and eosin, MT and PSR and observed under light and polarizing microscope, respectively.

Statistical Analysis:

ANOVA, Tukey's honestly significant difference post hoc multiple comparison test, Chi-square test and paired t-test were used for the statistical analysis.

Results:

As the grade of OSCC progressed, collagen fibers became thin, loosely packed and haphazard. The mean area fraction also decreased. They exhibited orange–red hue and strong birefringence in WDSCC, yellowish-orange hue and strong birefringence in MDSCC and greenish-yellow hue and weak birefringence in PDSCC.

Conclusion:

Initially, there is a reorganization of the collagen fibers in an attempt to prevent the invasion of tumor cells, but as cancer progresses, the stromal change enhances movement of the tumor cells within it, leading to metastasis.

An Immunohistochemical and Polarizing Microscopic Study of the Tumor Microenvironment in Varying Grades of Oral Squamous Cell Carcinoma

BACKGROUND

Invasion of epithelial cells into the connective tissue brings about massive morphological and architectural changes in the underlying stroma. Myofibroblasts reorganize the stroma to facilitate the movement of tumor cells leading to metastasis. The aim of this study was to determine the number and pattern of distribution of myofibroblasts and the qualitative and quantitative change that they cause in the collagen present in the stroma in various grades of oral squamous cell carcinoma (OSCC).

METHODS

The study was divided into two groups with group I (test group, 65 cases) consisting of 29 cases of well-differentiated squamous cell carcinoma, 25 moderately differentiated SCC, and 11 poorly differentiated SCC, and group II (control group) consisting of 11 cases of normal mucosa. Sections from each sample were stained with anti-α-smooth muscle actin (α-SMA) antibodies, hematoxylin and eosin, and Picrosirius red. Several additional sections from each grade of OSCC were stained with Masson's trichrome to observe the changes in collagen. For the statistical analysis, Fisher's exact test, Tukey's post hoc honest significant difference test, ANOVA, and the chi-square test were used, and p < .05 was considered statistically significant.

RESULTS

As the tumor stage progressed, an increase in the intensity α-SMA expression was seen, and the network pattern dominated in more dedifferentiated carcinomas. The collagen fibers became thin, loosely packed, and haphazardly aligned with progressing cancer. Additionally, the mean area fraction decreased, and the fibers attained a greenish yellow hue and a weak birefringence when observed using polarizing light microscopy.

CONCLUSIONS

Myofibroblasts bring about numerous changes in collagen. As cancer progresses, there isincrease in pathological collagen,which enhances the movement of cells within the stroma.

Evaluation and Comparison of the Biopathology of Collagen and Inflammation in the Extracellular Matrix of Oral Epithelial Dysplasias and Inflammatory Fibrous Hyperplasia Using Picrosirius Red Stain and Polarising Microscopy: A Preliminary Study

Background:

The role of tumour inflammation and the dysplastic epithelial-stromal interactions on the nature of collagen fibres in the extracellular matrix of dysplastic epithelium is not fully understood. The present study was aimed to evaluate and compare the inflammation and pathological stromal collagen (loosely packed thin disorganized collagen) present in mild, moderate and severe epithelial dysplasias with that of inflammatory fibrous hyperplasias. The basement membrane intactness of epithelial dysplasias was also evaluated to determine if dysplastic epithelial mesenchymal interaction has any role in the integrity of stromal collagen in epithelial dysplasia.

Methods:

Oral epithelial dysplasias, inflammatory fibrous hyperplasia and normal oral mucosal samples were used for the study. Packing, thickness and orientation of collagen fibres in mild, moderate and severe grades of oral epithelial dysplasias (n = 24), inflammatory fibrous hyperplasia (n = 8) and normal oral mucosal samples (n = 8) were analysed based on the polarisation of collagen fibres in picrosirius red polarising stain under polarising microscope.

Results:

All the grades of epithelial dysplasias showed greenish yellow birefringence confirming the presence of loosely arranged pathological collagen in the presence of moderate inflammation. All the cases of inflammatory fibrous hyperplasia showed red polarisation hue and moderate inflammation. A statistically significant difference was found in the packing and orientation of collagen when epithelial dysplasias and inflammatory fibrous hyperplasia were compared (P < 0.01). When the intactness of basement membrane integrity was compared in all the groups of epithelial dysplasia, a statistically significant result was obtained (P < 0.05).

Conclusions:

Presence of significant amount of loosely packed thin disoriented collagen even in mild epithelial dysplasia suggests that tumourigenic factors are released to connective tissue stroma much earlier than expected. Hence we suggest considering the integrity of extracellular matrix collagen, intactness of basement membrane and inflammation associated with dysplasia along with the anaplasia of epithelial cells in the microscopic assessment of dysplastic epithelium.

Stromal fibers in oral squamous cell carcinoma: A possible new prognostic indicator?

Background:

Many studies have been carried out to study the role of extracellular matrix proteins, growth factors and matrix metalloproteinases on tumor invasion. However, literature related to the analysis of connective tissue fibers in varying grades of oral squamous cell carcinoma (OSCC) is very limited.

Aim:

To analyze the changes in collagen and elastic fibers in varying grades of (OSCC).

Settings and Design:

This retrospective study was carried out using a light and polarizing microscope.

Materials and Methods:

Three sections each were cut from fifty samples of varying grades of OSCC and ten samples of control followed by staining with H and E, Picrosirius-Red and Verhoeff–Van Gieson. Qualitative and quantitative analysis of collagen and elastic fibers were accomplished using set criteria.

Statistical Analysis:

Data were entered into the Statistical Package for Social Sciences (SPSS) version 13.5 for analysis.

Results:

A change in colors of collagen fibers was seen on progressing from well to poorly differentiated OSCC. Thin collagen fibers predominantly exhibited greenish yellow, but the thick fibers exhibited a variety of colors. As the grade of OSCC progressed, collagen fibers were loosely packed haphazardly arranged. Statistically insignificant results were obtained for quantitative analysis of collagen and qualitative analysis of elastic fibers.

Conclusion:

The collagen fibers undergo a change in color, orientation and packing in the stroma of varying grades of OSCC. The uniqueness of this study lies in the exploration of elastic fibers in OSCC which has not been done so far.

Architectural Analysis of Picrosirius Red Stained Collagen in Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma using Polarization Microscopy

INTRODUCTION

Collagen degradation is important both for carcinogenesis and in its progression. Research regarding the co-relation of collagen with Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) is less explored.

AIM

To elucidate the nature of collagen in Oral Epithelial Dysplasia (OED) and Oral Squamous Cell Carcinoma (OSCC) using Picrosirius Red Stain (PSR) under polarizing microscopy.

MATERIALS AND METHODS

The study consisted of a total 40 samples which were divided into three groups. Group I included buccal mucosa as negative and irritation fibroma as positive control, group II consisted of OED and group III consisted of Oral Squamous Cell Carcinoma (OSCC). A histochemical analysis was conducted using PSR-polarization method by two independent observers.

RESULTS

The control group shows predominantly reddish-orange birefringence. In OED with the advancement of grades, the colour changed from yellowish-orange colour to yellow-greenish with progressive increase in greenish hue. As OSCC regresses from well to poorly differentiated, the colour changed from reddish-orange to yellowish orange to greenish-yellow suggesting a transition from mature to immature collagen.

CONCLUSION

An observable gradual change in collagen of both OED and OSCC was noted as they were proceeding from benign to critical step. Thus, PSR is a useful tool for studying stromal changes as supporting collagen shows the transition in the form besides the alterations in epithelial cells.

Involvement of PSMD10, CDK4, and Tumor Suppressors in Development of Intrahepatic Cholangiocarcinoma of Syrian Golden Hamsters Induced by Clonorchis sinensis and N-Nitrosodimethylamine

Background

Clonorchis sinensis is a group-I bio-carcinogen for cholangiocarcinoma (CCA). Although the epidemiological evidence links clonorchiasis and CCA, the underlying molecular mechanism involved in this process is poorly understood. In the present study, we investigated expression of oncogenes and tumor suppressors, including PSMD10, CDK4, p53 and RB in C. sinensis induced hamster CCA model.

Methods

Different histochemical/immunohistochemical techniques were performed to detect CCA in 4 groups of hamsters: uninfected control (Ctrl.), infected with C. sinensis (Cs), ingested N-nitrosodimethylamine (NDMA), and both Cs infected and NDMA introduced (Cs+NDMA). The liver tissues from all groups were analyzed for gene/protein expressions by quantitative PCR (qPCR) and western blotting.

Principal Findings

CCA was observed in all hamsters of Cs+NDMA group with well, moderate, and poorly differentiated types measured in 21.8% ± 1.5%, 13.3% ± 1.3%, and 10.8% ± 1.3% of total tissue section areas respectively. All CCA differentiations progressed in a time dependent manner, starting from the 8^th week of infection. CCA stroma was characterized with increased collagen type I, mucin, and proliferative cell nuclear antigen (PCNA). The qPCR analysis showed PSMD10, CDK4 and p16INK4 were over-expressed, whereas p53 was under-expressed in the Cs+NDMA group. We observed no change in RB1 at mRNA level but found significant down-regulation of RB protein. The apoptosis related genes, BAX and caspase 9 were found downregulated in the CCA tissue. Gene/protein expressions were matched well with the pathological changes of different groups except the NDMA group. Though the hamsters in the NDMA group showed no marked pathological lesions, we observed over-expression of Akt/PKB and p53 genes proposing molecular interplay in this group which might be related to the CCA initiation in this animal model.

Conclusions/Significance

The present findings suggest that oncogenes, PSMD10 and CDK4, and tumor suppressors, p53 and RB, are involved in the carcinogenesis process of C. sinensis induced CCA in hamsters.

Clonorchis sinensis is a helminth parasite and a carcinogenic agent for cholangiocarcinoma (CCA) or bile duct cancer in humans. Though a large and compelling body of evidence suggests an association between C. sinensis and CCA, the mechanism underlying at the genetic/proteomic level is little known. To explore the underlying molecular mechanism we investigated a number of genes/proteins in C. sinensis induced hamster CCA model. Here C. sinensis induced CCA successfully in all hamsters when introduced with N-nitrosodimethylamine. The histopathology confirmed the development of CCA and detected excessive collagen fibers, mucin and cell division related protein. The quantitative PCR analysis showed increased levels of oncogenes PSMD10, CDK4 and decreased level of tumor suppressor gene p53. The western blot analysis observed significant decrease of another tumor suppressor called RB protein. Genes/protein expressions were matched well with the pathological changes of CCA hamster. The present study suggests that oncogenes, PSMD10 and CDK4, and tumor suppressors gene p53 and protein RB, are involved in the carcinogenesis process of C. sinensis induced CCA in hamsters.

O papel das proteínas da matriz extracelular e das metaloproteinases em carcinomas de cabeça e pescoço: uma atualização bibliográfica

Interações entre células neoplásicas e constituintes da matriz extracelular (MEC) interferem fortemente no desenvolvimento tumoral, incluindo os localizados em cabeça e pescoço, pois influenciam a proliferação e sobrevivência celular, bem como a sua capacidade de migrar do sítio primário para outros tecidos e formar metástases. Essa migração celular é facilitada pela destruição parcial da MEC, a qual é realizada pelas metaloproteinases (MMPs), que representam uma família de mais de vinte endopeptidases, com atividade controlada pela expressão de inibidores específicos (TIMPs). Diversos estudos utilizando-se de marcadores para constituintes da MEC bem como pelas MMPs têm fornecido informações adicionais sobre o diagnóstico e prognóstico em carcinomas de cabeça e pescoço. Nesta revisão consideraremos o papel da MEC e das MMPs na progressão desses tumores, enfatizando que não somente a degradação proteolítica está envolvida neste processo, como também interações entre vários constituintes da MEC fornecem substrato para regulação e crescimento destes tumores.

The role of matrix extracellular proteins and metalloproteinases in head and neck carcinomas: an updated review

Interactions involving tumor cells and the extracellular matrix (ECM) strongly influence tumor development, including head and neck tumors, affecting cell proliferation and survival as well as the ability to migrate beyond the original location into other tissues to form metastases. These cell migration is often facilitated by partial destruction of the surrounding ECM, which is catalyzed by matrix metalloproteinases (MMPs), a family of more than 20 endopeptidases that is controlled by regulated expression of specific inhibitors (TIMPs). Several studies of ECM and MMPs markers have provided additional diagnostic and prognostic information in head and neck carcinomas. In this review, we are considering the role of ECM and MMPs in tumor progression, emphasizing its proteolytic contributors to this process, and interactions between several members of ECM providing substrate to regulation of this process.