Role of CD44 variant exon 6 in invasion of head and neck squamous cell carcinoma

CD44v6 specific CAR-NK cells for targeted immunotherapy of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a major challenge for current therapies. CAR-T cells have shown promising results in blood cancers, however, their effectiveness against solid tumors remains a hurdle. Recently, CD44v6-directed CAR-T cells demonstrated efficacy in controlling tumor growth in multiple myeloma and solid tumors such as HNSCC, lung and ovarian adenocarcinomas. Apart from CAR-T cells, CAR-NK cells offer a safe and allogenic alternative to autologous CAR-T cell therapy. In this paper, we investigated the capacity of CAR-NK cells redirected against CD44v6 to execute cytotoxicity against HNSCC. Anti-CD44v6 CAR-NK cells were generated from healthy donor peripheral blood-derived NK cells using gamma retroviral vectors (gRVs). The NK cell transduction was optimized by exploring virus envelope proteins derived from the baboon endogenous virus envelope (BaEV), feline leukemia virus (FeLV, termed RD114-TR) and gibbon ape leukemia virus (GaLV), respectively. BaEV pseudotyped gRVs induced the highest transduction rate compared to RD114-TR and GaLV envelopes as measured by EGFP and surface CAR expression of transduced NK cells. CAR-NK cells showed a two- to threefold increase in killing efficacy against various HNSCC cell lines compared to unmodified, cytokine-expanded primary NK cells. Anti-CD44v6 CAR-NK cells were effective in eliminating tumor cell lines with high and low CD44v6 expression levels. Overall, the improved cytotoxicity of CAR-NK cells holds promise for a therapeutic option for the treatment of HNSCC. However, further preclinical trials are necessary to test in vivo efficacy and safety, as well to optimize the treatment regimen of anti-CD44v6 CAR-NK cells against solid tumors.

The Antimicrobial Peptides Human β-Defensins Induce the Secretion of Angiogenin in Human Dermal Fibroblasts

The skin produces a plethora of antimicrobial peptides that not only show antimicrobial activities against pathogens but also exhibit various immunomodulatory functions. Human β-defensins (hBDs) are the most well-characterized skin-derived antimicrobial peptides and contribute to diverse biological processes, including cytokine production and the migration, proliferation, and differentiation of host cells. Additionally, hBD-3 was recently reported to promote wound healing and angiogenesis, by inducing the expression of various angiogenic factors and the migration and proliferation of fibroblasts. Angiogenin is one of the most potent angiogenic factors; however, the effects of hBDs on angiogenin production in fibroblasts remain unclear. Here, we investigated the effects of hBDs on the secretion of angiogenin by human dermal fibroblasts. Both in vitro and ex vivo studies demonstrated that hBD-1, hBD-2, hBD-3, and hBD-4 dose-dependently increased angiogenin production by fibroblasts. hBD-mediated angiogenin secretion involved the epidermal growth factor receptor (EGFR), Src family kinase, c-Jun N-terminal kinase (JNK), p38, and nuclear factor-kappa B (NF-κB) pathways, as evidenced by the inhibitory effects of specific inhibitors for these pathways. Indeed, we confirmed that hBDs induced the activation of the EGFR, Src, JNK, p38, and NF-κB pathways. This study identified a novel role of hBDs in angiogenesis, through the production of angiogenin, in addition to their antimicrobial activities and other immunomodulatory properties.

CD44v6 Targeted by miR-193b-5p in the Coding Region Modulates the Migration and Invasion of Breast Cancer Cells

Previous studies have shown that CD44 containing variant exon v6 (CD44v6) is highly expressed in many cancers and is related to tumor metastasis. However, the detailed mechanism of the regulatory pattern of CD44v6 in breast cancer remains unclear. Here, we found that CD44v6 was significantly upregulated in invasive breast cancer cell lines compared with low-invasive breast cancer cell lines. Cell migration and invasion could be suppressed by CD44v6 downregulation. MiRWalk and RNAhybrid software revealed miR-193b-5p as a miRNA targeting CD44v6 by binding to the exon v6 region. We found that the overexpression of miR-193b-5p inhibited the migration and invasion of Hs-578t and BT-549 cells, which could be rescued by restoring the expression of CD44v6. Next, we determined the potential of miR-193b-5p as an in vitro biomarker for breast cancer. Serum samples were obtained from 58 breast cancer patients, 36 patients with benign disease and 58 age-matched cancer-free controls. The results showed that the expression of miR-193b-5p in the serum was significantly lower in breast cancer patients than in controls and could distinguish cancer from cancer-free samples. The area under the receiver operating characteristic curve (ROC) for miR-193b-5p was 0.762(95% confidence interval: 0.674-0.851), which was higher than that of carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA15-3). Combining miR-193b-5p with CEA or CA15-3 could improve the diagnostic efficiency compared with the CEA and CA15-3 combination. Taken together, our results suggest that miR-193b-5p could function as a tumor-suppressive miRNA by targeting CD44v6 in breast cancer and that serum miR-193b-5p may serve as a biomarker for breast cancer diagnosis.

Biomarkers in Head and Neck Cancer an Update

The study is aimed at establishing the purpose of tumour markers, their application, classification, diagnostic and therapeutic roles in the management of head and neck cancer. A literature review using Medline, Scopus, Google Scholar, the Cochrane Database of Systematic Reviews and the Cochrane central register of controlled trials for articles published between 1993 and 2016 on tumour markers and their role in head and neck cancer was performed. A broader search of prognostic markers in head and neck cancer was also carried out to avoid missing other pertinent markers. Natural history, tumour biology, stage and prognostic factors influence the outcome of management in patients with Head and Neck Squamous cell carcinoma (HNSCC). Evaluation of the cellular lineage and histogenic origin of diverse neoplasms can be done using tumour biomarkers. Identifying predictive tumour markers can lead to improvement in preventive management of HNSCC. There has been remarkable advancement in molecular technology with gene expression and proteomic profiling. Integration of specific tumour markers into routine clinical practice requires substantiation through well designed clinical trials. The investigation of tumour markers is imperative as they influence the prognosis of HNSCC and provide the potential to improve outcomes of treatment through targeted therapy. We have outlined recent tumour biomarkers in this review which have significant role in diagnosis, screening and prognostication in HNSCC. Recent advancement in clinical applications, therapeutic strategies of tumour markers has been highlighted.

Crosstalk between Raf-MEK-ERK and PI3K-Akt-GSK3β signaling networks promotes chemoresistance, invasion/migration and stemness via expression of CD44 variants (v4 and v6) in oral cancer

BACKGROUND

The cell-surface glycoprotein CD44 is an important oral cancer stem cell (OCSC) marker and plays significant role in oral squamous cell carcinoma (OSCC) aggressiveness, however, the regulation of CD44 is incompletely understood.

METHODS

In the present study, 145 fresh human OSCC tissue specimens, including 18 adjacent normal, 42 noninvasive (N0), 53 invasive tumor samples (N_1-3) and 32 chemo-radiation resistant samples (RCRT), were included. The expression of CD44 standard (CD44s) and variants (CD44v4, CD44v6); the activation of pERK1/2, GSK3β, NICD (Notch) pathways; the cell viability; and the MMP-9/-2 activity were assessed using RT-PCR, immunohistochemistry, Western blotting, MTT assay and gelatin zymography. OSCC cell lines, including parental (SCC9/SCC4) and Cisplatin-resistant (CisR-SCC9/-SCC4) cells, were used. Knock down of CD44v4/CD44v6 (by siRNA) or inactivation of MAPK/PI3K pathways using specific PD98059/LY294002 was achieved for in vitro analysis of chemoresistance and invasion/migration.

RESULTS

Elevated CD44 variants were associated with overall OSCC progression, chemoresistance and invasion. Positive correlations were observed, mainly between the expression of CD44v4 and the activation of ERK1/2 causing chemoresistance, whereas CD44v6 expression and inactivation of GSK3β caused invasiveness of OSCC. Cisplatin resistant, CisR-SCC9/SCC4 cell lines showed OCSC properties. Inhibition of MEK/ERK1/2 by SMI or knock down (KD) of CD44v4 by siRNA reversed cisplatin-resistance, whereas blocking the PI3K/Akt/GSK3β pathway by SMI or KD of CD44v6 isoforms by respective siRNA diminished invasion/metastasis potential.

CONCLUSION

Collectively, our results demonstrated that CD44v4 expression is more linked with ERK1/2 activation and promote cisplatin resistance, whereas CD44v6 expression is associated primarily with PI3K/Akt/GSK3β activation and driving tumor invasion/migration.

Cancer stem cells in head and neck cancer

Cancer stem cells (CSCs), also called “cells that start the tumor,” represent in themselves one of the most topical and controversial issues in the field of cancer research. Tumor stem cells are able to self-propagate in vitro (self-renewal), giving rise both to other tumor stem cells and most advanced cells in the line of differentiation (asymmetric division). A final characteristic is tumorigenicity, a fundamental property, which outlines the tumor stem cell as the only cell able to initiate the formation of a tumor when implanted in immune-deficient mice. The hypothesis of a hierarchical organization of tumor cells dates back more than 40 years, but only in 1997, thanks to the work of John Dick and Dominique Bonnet, was there the formal proof of such an organization in acute myeloid leukemia. Following this, many other research groups were able to isolate CSCs, by appropriate selection markers, in various malignancies, such as breast, brain, colon, pancreas, and liver cancers and in melanoma. To date, however, it is not possible to isolate stem cells from all types of neoplasia, particularly in solid tumors. From a therapeutic point of view, the concept of tumor stem cells implies a complete revision of conventional antineoplastic treatment. Conventional cytotoxic agents are designed to target actively proliferating cells. In the majority of cases, this is not sufficient to eliminate the CSCs, which thanks to their reduced proliferative activity and/or the presence of proteins capable of extruding chemotherapeutics from the cell are not targeted. Therefore, the theory of cancer stem cells can pose new paradigms in terms of cancer treatment. Potential approaches, even in the very early experimental stages, relate to the selective inhibition of pathways connected with self-renewal, or more specifically based on the presence of specific surface markers for selective cytotoxic agent vehicles. Finally, some research groups are trying to induce these cells to differentiate, thus making them easier to remove. For all these reasons, we have collected existing literature on head and neck cancer stem cells that correlate the biological characteristics of this subpopulation of cancer cells with the clinical behavior of tumors.

Characteristics of CD44 alternative splice pattern in the course of human colorectal adenocarcinoma progression

BACKGROUND

CD44 is considered as 'a' metastasis associated gene, despite the fact that it is an umbrella term for a group of molecules produced from a single gene by alternative splicing. However, little consideration is given to the above in the literature of colorectal carcinomas as well as other tumour types, leading to confusion and contradictory results about its possible role in tumour progression.

METHODS

We compared the CD44 alternative splice pattern (ASP) of three genetically different human colorectal cancer cell lines (HT25, HT29, HCT116) using a series of PCR reactions and next- generation sequencing method, as well as identified a colorectal adenocarcinoma specific CD44 ASP. This ASP was further investigated in terms of its qualitative and quantitative stability in our experimental iso- and xenograft mouse models for colorectal cancer progression. A complex preclinical experimental set-up was established to separately test the different steps of tumour progression and the role of tumour microenvironment, respectively, focusing on the role of 'CD44' in this process.

RESULTS

We managed to present a colorectal cancer-specific CD44 ASP, which remained unchanged from cell lines throughout primary tumour formation and metastatic progression. Furthermore, we report a unique roster of all expressed CD44 variant isoforms characteristic to colorectal cancer. Finally, on quantitative assessment of the variable exons v3 and v6, higher co-expression levels were found to be characteristic to metastatically potent tumour cells.

CONCLUSION

Particular CD44 variant isoforms seem to act as "metastasis genes" via tumour microenvironment-driven shifts in v3 and v6 expressions. However, this function may just affect a minority of tumour subclones. This fact and the huge potential number of different CD44 splice variants that can contain v3 and v6 domains can explain incoherence of clinical studies regarding functional asessment of CD44 variants, as well as diminish the chances of using CD44 variants for predictive purpose.

Detection and clinical significance of CD44v6 and integrin-β1 in pancreatic cancer patients using a triplex real-time RT-PCR assay

The cell adhesion molecules CD44v6 and integrin-β1 are associated with the progression and metastasis of cancer. A novel triplex real-time reverse transcription polymerase chain reaction (qRT-PCR) assay was developed to quantify CD44v6 and integrin-β1 gene expression in peripheral blood mononuclear cells from 30 pancreatic cancer (PC) patients and 12 healthy individuals. The standard curve of the triplex qRT-PCR was constructed by optimizing the reaction condition and the amplification efficiency was 102.5, 101.1, and 100.6 % for CD44v6, integrin-β1 and endogenous gene (β-actin) amplification. Nonspecific bands were not observed from the triplex qRT-PCR amplification and the detection limit of this assay was 100 copies. Expression levels of CD44v6 and integrin-β1 gene were significantly lower in healthy individuals than PC patients (P<0.05). CD44v6 and integrin-β1 gene expression were not associated with the sex, age, and tumor position in PC (P>0.05). CD44v6 gene expression was significantly associated with clinical stage, liver metastasis, and tumor size (P<0.05). Integrin-β1 gene expression was significantly associated with clinical stage and liver metastasis (P<0.05). This triplex qRT-PCR assay may provide a useful tool for diagnosis, prognosis, and therapeutic evaluation in PC.

Cancer stem cells hypothesis and stem cells in head and neck cancers

There is increasing evidence that the growth and spread of cancer is driven by a small subpopulation of cancer cells, defined as cancer stem cells (CSCs). Recent data indicate that the initiation, growth, recurrence and metastasis of cancers are related to the behavior of a small population of malignant cells with properties of stem cells, and information about them are potentially helpful in identifying the target for the tumor's therapeutic elimination. The presence of subpopulation cells with phenotypic and behavioral characteristics corresponding to both normal epithelial stem cells and to cells capable of initiating tumors has been also reported in head and neck squamous cell carcinomas (HNSCCs).

Expression of the membrane-cytoskeletal linker Ezrin in salivary gland adenoid cystic carcinoma

OBJECTIVE

The aim of this study was to investigate the relationship between membrane cytoskeleton linker protein Ezrin and CD44v6, iNOS, Ki-67, and clinicopathologic characteristics, and the prognostic significance of Ezrin expression in salivary gland adenoid cystic carcinoma (SACC).

STUDY DESIGN

Immunohistochemistry and reverse-transcription polymerase chain reaction were used to quantify the expression of Ezrin, CD44v6, inducible nitric oxide synthase (iNOS), and Ki-67 in 75 primary SACCs, 25 tumor-free salivary tissues, and 2 SACC cell lines (ACC-M and ACC-2). Survival analysis was performed to find the prognostic significance of Ezrin expression.

RESULTS

Expressions of Ezrin, CD44v6, iNOS, and Ki-67 in SACC tissues, especially with distant metastasis, were significantly higher than in tumor-free tissues. Ezrin mRNA and protein levels in ACC-M cells were significantly higher than in ACC-2 cells. Ezrin, CD44v6, iNOS, and Ki-67 expressions were significantly higher in solid pattern than in cribriform and tubular patterns. Ezrin and its partners, CD44v6, iNOS, and Ki-67, were significantly related to tumor size, clinical stage, perineural and vascular invasion, and recurrence. Furthermore, Ezrin had an independent prognostic effect on overall survival.

CONCLUSIONS

The increased expression of Ezrin and its partners, CD44v6, iNOS, and Ki-67, in SACC correlated with histologic patterns, may play a role in distant metastasis, and might indicate poor clinical outcome.

Significance of site-specific prognosis of cancer stem cell marker CD44 in head and neck squamous-cell carcinoma

In several recent studies, CD44 expression has been associated with aggressive behavior in cancers of different types. CD44 expression is also linked to cancer stem cells, which have been shown to play a significant role in tumor progression and poor prognosis in head and neck squamous cell carcinoma (HNSCC), as well as in other cancers. Although CD44 is a potential prognostic marker, it has not been adopted to wider clinical use as a part of treatment planning in HNSCC patients. The aim of this research was to study whether CD44 overexpression is associated with 5year overall survival in HNSCC. We also studied site-specific associations between increased CD44 expression and 5year overall survival. Associations between relative tumor CD44 expressions and smoking, heavy alcohol consumption, histological grade of cancer, TNM staging and HNSCC staging were also studied. In total, 135 paraffin-embedded blocks from HNSCC patients were stained immunohistochemically with a CD44 antibody and were classified by the anatomic location of the tumor. CD44 overexpression had statistically significant association with decreased 5year survival rates when all HNSCC samples were studied (p<0.001). Significant association between intense CD44 expression and poor 5year survival rates was found in the patients with SCC of the oro- and hypopharynx (p<0.001) and the larynx (p=0.042). In patients suffering from HNSCC in the oral cavity, CD44 overexpression did not have a significant effect on overall 5year survival rates. Heavy smoking of over 10 pack years had a significant association with tumor CD44 overexpression (p=0.009). Only pharyngeal (p=0.046) and laryngeal (p=0.047) SCC, but not oral-cavity SCC, had statistically significant associations between heavy smoking and CD44 overexpression when HNSCC was studied in regional groups. Alcohol consumption and tumor grade did not have a significant association with the tumor's CD44 expression. Our results suggest that CD44 overexpression could be used as a sign of aggressiveness, in addition to the HNSCC staging, as a prognostic factor in pharyngeal and laryngeal HNSCC and to assist in treatment selection.

Predicting invasive phenotype with CDH1, CDH13, CD44, and TIMP3 gene expression in primary breast cancer

We aimed to determine changes in the expression of the genes CDH1, CDH13, CD44, and TIMP3 to look for any relationship between them, HER2 and ESR1 expression at the RNA level, and the histopathological properties of tumors. We also analyzed the expression properties of double-negative (estrogen receptor [ER] and human epidermal growth factor receptor [HER2] both negative) breast tumors. Expression status was studied in fresh tissue at the mRNA level with quantitative PCR using hydrolysis probes. Sixty-two cancer patients and four normal controls were included in the study. When the tumor group was analyzed as a whole, the correlations of ESR1 with CDH1, CDH13, and TIMP3 were P < 0.05, P < 0.005, and P < 0.005, respectively. In ER-positive tumors, CDH1 and CDH13 were correlated directly (P < 0.005) when HER2 was correlated with CDH1, CDH13, and TIMP3 indirectly (P < 0.005, P < 0.005, and P < 0.05, respectively). CDH1 and CD44 had a strong indirect correlation (P < 0.005) in ER-negative tumors. There were significant differences in the expression levels of the CDH13, TIMP3, and CD44 genes (P < 0.005, P < 0.005, and P < 0.05, respectively) between the ER-positive and -negative groups. All four genes were found to be correlated with invasive properties in both ER-positive and -negative tumors. In double-negative tumor samples, only CD44 had a significant and strong correlation with stage, lymph node involvement, and metastasis (P < 0.05, P < 0.005, and P < 0.05, respectively). As a conclusion, a decrease in CDH1, CDH13, and TIMP3 expression levels with an increase in CD44 can be used as an indicator for invasion in both ER-positive and -negative breast tumors. In double-negative tumor tissues, CD44 can be considered a marker for aggressive properties.

CD44 variant isoforms in head and neck squamous cell carcinoma progression

OBJECTIVES/HYPOTHESIS

The CD44 family of receptors includes multiple variant isoforms, several of which have been linked to malignant properties including migration, invasion, and metastasis. The objective of this study was to investigate the role of the CD44 v3, v6, and v10 variant isoforms in head and neck squamous cell carcinoma (HNSCC) tumor progression behaviors.

STUDY DESIGN

Laboratory study involving cell cultures and clinical tissue specimens.

METHODS

Analysis of the expression of standard CD44s and the CD44 variant isoforms v3, v6, and v10 was carried out in the HNSCC cell line, HSC-3. The role of CD44 isoforms in migration, proliferation, and cisplatin resistance was determined. Immunohistochemical analysis was performed on clinical tissue specimens obtained from a series of 82 HNSCC patients. The expression of standard CD44s and the CD44 v3, v6, and v10 variants in primary tumor specimens (n = 82) and metastatic cervical lymph nodes (n = 24) were analyzed with respect to various clinicopathologic variables.

RESULTS

HSC-3 cells express at least four CD44 isoforms, and these CD44 isoforms mediate migration, proliferation, and cisplatin sensitivity. Compared with primary tumors, a greater proportion of metastatic lymph nodes demonstrated strong expression of CD44 v3 (lymph node 14/24 vs. primary tumor 38/82), CD44 v6 (lymph node 18/24 vs. primary tumor 26/82), and CD44 v10 (lymph node 14/24 vs. primary tumor 16/82), while expression of standard CD44 was not significantly different in metastatic lymph nodes and primary tumors (lymph node 10/24 vs. primary tumor 60/82). Expression of CD44 variant isoforms were associated with advanced T stage (v3 and v6), regional (v3) and distant (v10) metastasis, perineural invasion (v6), and radiation failure (v10). CD44 v6 and CD44 v10 were also significantly associated with shorter disease-free survival.

CONCLUSIONS

CD44 isoforms mediate migration, proliferation, and cisplatin sensitivity in HNSCC. Furthermore, expression of certain CD44 variants may be important molecular markers for HNSCC progression and should be investigated as potential therapeutic targets for therapy.

Immunohistochemical expression of E-cadherin and CD44v6 in squamous cell carcinomas of the lower lip and tongue

This study analyzed the immunohistochemical expression of E-cadherin and CD44v6 in 15 squamous cell carcinomas (SCCs) of lower lip and 15 SCCs of tongue in order to verify a possible association between these proteins and the anatomic location of the lesion, nodal metastasis and histological grading of malignancy. The pattern of expression and number of immunopositive cells were evaluated. The results were analyzed with the Fisher's exact test, Mann-Whitney test and Spearman's Correlation Coefficient (r). using the SPSS software 10.0 for Windows. Statistical significance was set at 5% determined for a p-value<0.05 for all tests. There was no significant difference (p>0.05) in the pattern of expression and number of immunopositive cells for E-cadherin and CD44v6, regarding the anatomical location and nodal metastasis. For the histological grading, low score SCCs showed higher immunopositivity for E-cadherin and CD44v6, both for the pattern of expression and number of immunopositive cells (p<0.05). There was a negative correlation between the total score of malignancy and the pattern of expression and number of immunopositive cells for E-cadherin and CD44v6 (p<0.05). In conclusion, SCCs of the lower lip and tongue did not reveal significant differences in the expression of E-cadherin and CD44v6. The expression of these adhesion molecules revealed association only with tumor histological grading of malignancy. Therefore, these results suggest that E-cadherin and CD44v6 may not help elucidating the differences between the biological behavior of SCCs of the lower lip and tongue.

CD44 attenuates metastatic invasion during breast cancer progression

Metastatic invasion is the primary cause of breast cancer mortality, and adhesion receptors, such as CD44, are believed to be critical in this process. Historically, primary breast tumor epithelium has been investigated in isolation from other tissue components, leading to the common interpretation that CD44 and its primary ligand, hyaluronan, promote invasion. Here, we provide in vivo evidence showing CD44 antagonism to breast cancer metastasis. In a mouse model of spontaneously metastasizing breast cancer (MMTV-PyV mT), we found that loss of CD44 promotes metastasis to the lung. Localization studies, in combination with a novel hyaluronan synthase-GFP transgenic mouse, show a restricted pattern of expression for CD44 and hyaluronan. Whereas CD44 is expressed in tumor epithelium, hyaluronan synthase expression is restricted to stromal-associated cells. This distinct CD44 and hyaluronan pattern of distribution suggests a role for epithelial-stromal interaction in CD44 function. To define the relevance of this spatial regulation, we developed an in vitro invasion assay to emulate invasion into the extracellular matrix. Invasion of CD44-positive tumor cells was inhibited in hyaluronan-containing matrices, whereas blocking CD44-hyaluronan association increased invasion. Collectively, these data show that during breast cancer progression, hyaluronan-CD44 dynamics occurring through epithelial-stromal interactions are protective against metastasis.

Staging of the neck in patients with head and neck squamous cell cancer: Imaging techniques and biomarkers

Regional metastasis is an important factor in the treatment and prognosis of head and neck cancer patients. Current treatment strategies rely on staging based on the still limited accuracy of imaging techniques to detect regional metastases. If more certainty about the nodal status could be attained, treatment strategies concerning the neck could be better adjusted to the individual patient. The continuing improvement of established imaging techniques and the introduction of new imaging modalities will add to better staging. Moreover, the additional use of biomarkers studied on a protein, RNA or DNA level may provide even better information about the chance of occult nodal metastasis in head and neck cancer patients.

Expression of E-cadherin, CD44s, and CD44v6 in laryngeal and pharyngeal carcinomas

OBJECTIVE

Tumors arising from different sites of the head and neck area have very different clinical behavior. Loss or reduction of expression of adhesion molecules has been assumed to play a critical role in the development of head and neck carcinomas. The aim of this study is to determine if there are differences in the expression of adhesion molecules E-cadherin, CD44s, and CD44v6 in pharyngeal and laryngeal squamous-cell carcinomas.

MATERIALS AND METHODS

E-cadherin, CD44s, and CD44v6 expression was determined by immunohistochemistry in paraffin-embedded tissue specimens from 72 patients with squamous-cell carcinoma, 37 of the pharynx and 35 of the larynx.

RESULTS

Expression of CD44s was significantly lower in pharyngeal than in laryngeal tumors (P =.01). No differences in the expression of E-cadherin and CD44v6 were observed between these sites.

CONCLUSIONS

These data suggest that there are some differences at molecular level between the different subsites of head and neck cancer.

Adhesion molecule CD44 expression in non-tumour epithelium adjacent to tongue cancer

An immunohistochemical study was performed of changes in the expression of adhesion molecule CD44 in 32 adjacent non-tumour epithelia (ANTE) to lingual carcinomas and in the tumour tissue, using anti-CD44 monoclonal antibody DF1485. The aim was to evaluate the importance of these changes as an early event in lingual carcinogenesis. The ANTE was histologically normal in 22 cases (68.8%) and presented epithelial dysplasia in 10 (32.2%). Three cases of normal and dysplastic ANTE, respectively, were CD44- (9.4%). Negative CD44 expression was significantly more frequent in tumours with lower percentages of CD44+ cancer cells, both in normal (P=0.014) and dysplastic (P=0.033) ANTE. The expression in normal ANTE was also significantly associated with clinical stage (P=0.040) and presence of extracapsular nodal spread (P=0.013). Therefore, loss of CD44 expression in ANTE can be considered an early event in lingual carcinogenesis and a marker of major alterations of CD44 expression in the derived tumour tissue.

Significance of immunohistochemical over-expression of CD44v6 as an indicator of malignant potential in esophageal squamous cell carcinoma

PURPOSE

The aim of the current study was to find out a clinicopathologic significance of CD44v6 over-expression in esophageal squamous cell carcinoma (ESCC), which has not been elucidated fully.

METHODS

Immunohistochemical expression of CD44v6 was examined for 81 ESCCs. Correlation of CD44 over-expression with the clinicopathologic features were investigated.

RESULTS

Thirty-eight ESCCs (46.9%) had over-expression of CD44v6. The proportions of the incidence of lymph node metastasis (P=0.039), lymphatic permeation (P=0.003), and blood vessel invasion (P=0.037) in ESCCs with over-expression of CD44v6 were significantly higher than those in ESCCs without over-expression of CD44v6. The stage of the tumor in ESCCs with over-expression of CD44v6 was significantly more advanced (P=0.045). Survival rates of patients with ESCC with over-expression of CD44v6 were significantly worse (P=0.0005). Moreover, CD44v6 over-expression (P=0.048) as well as blood vessel invasion (P=0.014) and stage of the tumor ( P=0.010) were factors independently associated with the unfavorable prognosis of the patients with ESCC.

CONCLUSIONS

Over-expression of CD44v6 can be an indicator of the malignant potential of ESCC.

[Prognostic significance of the expression of adhesion molecules E-cadherin, Cd44s and CD44V6 in supraglottic squamous carcinoma]

OBJECTIVE

To establish the prognostic significance of the expression of adhesion molecules E-cadherin, CD44s and CD44v6 in squamous cell carcinomas of the supraglottic larynx.

MATERIAL AND METHODS

The expression of the studied molecules was determined by immunohistochemistry in paraffin-embedded tissue specimens from 101 patients.

RESULTS

The expression of the three molecules was reduced in carcinomas compared to normal epithelium. The cases with recurrence showed an E-cadherin and CD44s expression significantly lower than those cases without recurrence. Reduced expression of any of the three molecules correlated with a decrease in survival, although the differences were not significant. In multivariate analysis only nodal stage (N) was an independent prognostic factor.

CONCLUSIONS

Although reduced expression of E-cadherin, CD44s and CD44v6 seems to be related to a poor prognosis in supraglottic squamous cell carcinomas, these changes do not offer a useful adjunct to current prognostic indicators.

CD44 in cancer

CD44 is a multistructural and multifunctional cell surface molecule involved in cell proliferation, cell differentiation, cell migration, angiogenesis, presentation of cytokines, chemokines, and growth factors to the corresponding receptors, and docking of proteases at the cell membrane, as well as in signaling for cell survival. All these biological properties are essential to the physiological activities of normal cells, but they are also associated with the pathologic activities of cancer cells. Experiments in animals have shown that targeting of CD44 by antibodies, antisense,and CD44-soluble proteins markedly reduces the malignant activities of various neoplasms, stressing the therapeutic potential of anti-CD44 agents. Furthermore, because alternative splicing and posttranslational modifications generate many different CD44 sequences, including, perhaps, tumor-specific sequences, the production of anti-CD44 tumor-specific agents may be a realistic therapeutic approach. However, in many cancers (renal cancer and non-Hodgkin's lymphomas are exceptions), a high level of CD44 expression is not always associated with an unfavorable outcome. On the contrary, in some neoplams CD44 upregulation is associated with a favorable outcome. Even worse, in many cases different research grows analyzing the same neoplastic disease reached contradictory conclusions regarding the correlation between CD44 expression and disease prognosis, possibly due to differences in methodology. These problems must be resolved before applying anti-CD44 therapy to human cancers.

Clinicopathologic significance of expression of CD44s and CD44v6 isoforms in squamous cell carcinoma of the supraglottic larynx

CD44 splice variants are assumed to have a critical role in the malignant progression of many human tumors. However, the clinical significance of CD44 expression is not yet understood. The aim of this study was to investigate the prognostic significance of expression of CD44s and CD44v6 isoforms in squamous cell carcinomas of the supraglottic larynx. CD44s and CD44v6 expression was determined by immunohistochemical analysis of paraffin-embedded tissue specimens from 101 patients. There was a significant correlation between decreased CD44s or CD44v6 expression and a poorer histologic differentiation. No relationship was observed with T stage or nodal metastasis. Decreased CD44s expression, but not CD44v6 expression, correlated with increased recurrence rates. There was no correlation between the decreased expression of any isoform tested and survival. These data confirm a reduction of CD44s and CD44v6 expression in poorly differentiated tumors. However, these changes do not offer a useful adjunct to current prognostic indicators.