Inhibition of cyclooxygenase-2 suppresses invasiveness of oral squamous cell carcinoma cell lines via down-regulation of matrix metalloproteinase-2 and CD44

Expression of cyclooxygenase-2 (COX-2) in tumors is known to be associated with enhanced angiogenesis, suppression of host immunity, and tumor invasion. In the present study, human oral squamous cell carcinoma (OSCC) cell lines NA and HSC-4 were used to evaluate the effects of NS-398, a selective inhibitor of COX-2, and COX-2 antisense oligonucleotide (COX-2 AS) on the invasion activity of OSCC cells. Matrigel invasion assay revealed that the invasiveness of NA and HSC-4 was suppressed by treatment with either NS-398 or COX-2 AS. These reagents down-regulated the secretion of matrix metalloproteinase-2 (MMP-2) to culture supernatant as well as the expression of MMP-2 mRNA and protein. Membrane-type 1 matrix metalloproteinase (MT1-MMP), an activator of proMMP-2, was also down-regulated by treatment with these reagents. Furthermore, expression of CD44 on the surface of these cells was reduced by treatment with either NS-398 or COX-2 AS. In addition, MMP-2 antisense oligonucleotides reduced the expression of CD44 on the surface of both OSCC cell lines. These findings suggest that NS-398 and COX-2 AS suppress the invasiveness of OSCC cells via down-regulation of MMP-2 and CD44. Genetic or pharmacological inhibition of COX-2 may therefore be a beneficial strategy in the treatment of OSCC patients.This revised version was published online in August 2005 with a corrected cover date.     

Inhibition of cyclooxygenase-2 suppresses invasiveness of oral squamous cell carcinoma cell lines via down-regulation of matrix metalloproteinase-2 and CD44

Expression of cyclooxygenase-2 (COX-2) in tumors is known to be associated with enhanced angiogenesis, suppression of host immunity, and tumor invasion. In the present study, human oral squamous cell carcinoma (OSCC) cell lines NA and HSC-4 were used to evaluate the effects of NS-398, a selective inhibitor of COX-2, and COX-2 antisense oligonucleotide (COX-2 AS) on the invasion activity of OSCC cells. Matrigel invasion assay revealed that the invasiveness of NA and HSC-4 was suppressed by treatment with either NS-398 or COX-2 AS. These reagents down-regulated the secretion of matrix metalloproteinase-2 (MMP-2) to culture supernatant as well as the expression of MMP-2 mRNA and protein. Membrane-type 1 matrix metalloproteinase (MT1-MMP), an activator of proMMP-2, was also down-regulated by treatment with these reagents. Furthermore, expression of CD44 on the surface of these cells was reduced by treatment with either NS-398 or COX-2 AS. In addition, MMP-2 antisense oligonucleotides reduced the expression of CD44 on the surface of both OSCC cell lines. These findings suggest that NS-398 and COX-2 AS suppress the invasiveness of OSCC cells via down-regulation of MMP-2 and CD44. Genetic or pharmacological inhibition of COX-2 may therefore be a beneficial strategy in the treatment of OSCC patients.     

nm23-H1 suppresses invasion of oral squamous cell carcinoma-derived cell lines without modifying matrix metalloproteinase-2 and matrix metalloproteinase-9 expression

nm23-H1 is a candidate gene for the suppression of cancer metastasis. Several studies on human breast, hepatocellular, gastric, ovarian, and colon carcinomas and melanomas have shown that reduced nm23-H1 expression was closely related to metastatic progression with poor prognosis. However, the biochemical mechanism by which nm23-H1 suppresses the metastasis has yet to be elucidated. In this study, we analyzed the correlation between nm23 expression, cell motility, and the invasive abilities of six different oral squamous cell carcinoma cell lines (HSC2, HSC3, HSC4, KB, OSC19, and OSC20). Reduced mRNA/protein expression of the nm23-H1 was observed in three cell lines (HSC2, HSC3, and HSC4). These cell lines exhibited increased cell motility and an invasive character on organotypic raft culture. On the other hand, the cell lines (KB, OSC19, and OSC20) that showed a higher expression of nm23-H1 exhibited a threefold to fivefold reduced motility and also reflected fewer invasions compared to the former three cell lines. Because the HSC3 cells demonstrated the lowest nm23-H1 expression with the highest cell motility and invasive character, we established nm23-H1-transfected HSC3 cell lines to investigate whether exogenous nm23-H1 protein could inhibit cell migration and invasive activity. These transfectants showed a significant reduction in cell motility with exogenous nm23-H1 in a dose-dependent manner, and exhibited a noninvasive character. An immunofluorescence study demonstrated a distinct stress-fiber distribution at peripheral region of these transfectants. However, no significant difference of matrix metalloproteinase (MMP)-2 and MMP-9 expression was observed between mock transfectant and nm23-H1-transfected cells. These findings suggest that nm23-H1 inhibits the invasive activity of oral squamous cell carcinoma by suppression of cell motility without altering the MMP-2 and MMP-9 status.     

Comparative analysis of the expression of proliferating cell nuclear antigen, p53, bax, and bcl-2 in oral lichen planus and oral squamous cell carcinoma

Several epidemiologic studies have shown the malignant transformation potential of oral lichen planus; however, this potential is subject of much controversy. To evaluate the expression of proteins related to the cell proliferation and apoptosis processes in oral lichen planus, we compared oral lichen planus with oral squamous cell carcinoma. Twenty-four cases of each lesion were submitted according to streptavidin-biotin technique to evaluate the immunohistochemical expression of proliferating cell nuclear antigen, p53, bax, and bcl-2 proteins. χ² test showed no statistically significant differences between the expression of p53, bax, and bcl-2 in oral lichen planus and oral squamous cell carcinoma (P > .05). However, the expression of proliferating cell nuclear antigen was significantly lower in oral lichen planus than in oral squamous cell carcinoma (P < .05). No statistically significant differences between the expression of p53, bax, and bcl-2 in oral lichen planus and oral squamous cell carcinoma were observed, which may be an evidence of the potential of malignant transformation of oral lichen planus.     

Sequential activation and production of matrix metalloproteinase-2 during breast cancer progression

The proteolytic processes are thought to be the critical point in tumor invasion and metastasis, mainly by matrix metalloproteinases (MMPs) and serine proteases. We measured the activity of MMP-2 from 28 normal, 12 benign and 126 breast cancer tissues using gelatin zymography. Inactive MMP-2 (72 kD) was expressed in 53.6% of the normal and 66.6% of the cancer tissues, respectively (P= 0.77), while active MMP-2 (62 kD) was expressed in 28.6% and 73.0%, respectively (P = 0.003). The enzymatic activity of active MMP-2 (62 kD) measured in the gel band area was 4.0 ± 7.2 mm² in normal breasts, 7.7 ± 9.8 mm² in benign breast diseases, 9.5 ± 8.5 mm² in ductal carcinoma in situ (DCIS), and 12.0 ± 13.7 mm² in invasive cancers. The MMP-2 activation ratio (62 kD/62 kD + 72 kD) was 0.12 ± 0.18 in normal tissues, 0.10 ± 0.20 in benign diseases, 0.61 ± 0.22 in DCIS, and 0.50 ± 0.28 in invasive cancers. In conclusion, MMP-2 activation was the main cause of the increased 62 kD MMP-2 activity during the early phase of breast cancer, while production of MMP-2 supplemented the increased 62 kD activity in the late phase. We suggest, therefore, that these differential expressions of MMP-2 activation and production during the different stages of breast cancer progression are potential therapeutic targets for biological or gene therapy under the concept of stage-oriented cancer treatment.[]     

An immunohistochemical study of the extracellular matrix in oral squamous cell carcinoma and its association with invasive and metastatic potential

The expression of extracellular matrices (ECMs) laminin (LN), type IV collagen (IV C), heparansulphate proteoglycan (HS-PG), fibronectin (FN), tenascin (TN), decorin and vitronectin (VN) was examined immunohistochemically in 112 primary tumours and 29 metastatic cervical lymph nodes in oral squamous cell carcinoma (OSCC). In highly invasive primary tumours, the expression of LN, IV C and HS-PG in the basement membrane along the tumour-stroma borderline and the expression of decorin and VN in the tumour stroma at the invasive site were all significantly decreased. The expression of FN and TN in the tumour stroma at the same site was markedly increased. In peritumour stroma in metastatic lymph nodes, LN, IV C, HS-PG, decorin and VN were weakly expressed, while FN and TN were strongly expressed. Thus, the staining pattern of the ECMs in the metastatic lymph nodes was similar to that in highly invasive primary tumours. Furthermore, in primary tumours of metastatic cases, the expression of LN, IV C, HS-PG, decorin and VN obviously decreased, while the expression of FN and TN increased when compared with those of the non-metastatic cases. The investigation of ECMs in OSCC was valuable in predicting tumour behaviour.     

D2-40 immunoreactivity in penile squamous cell carcinoma: a marker of aggressiveness

D2-40 immunohistochemical expression was investigated in tissue specimens from 39 patients with squamous cell carcinoma of the penis who underwent partial or total penectomy between 1987 and 2008. Patient age, tumor size, and grade; D2-40-positive lymphatic vessel density in intratumoral, peritumoral, and normal tissue; cell positivity for D2-40 in intratumoral and normal tissue; and D2-40 staining intensity and distribution were analyzed and correlated with disease-specific survival. Analysis of D2-40-positive lymphatics disclosed that mean lymphatic vessel density was greater in peritumoral tissue than in intratumoral and normal tissue and lower in patients with lymph node metastasis than in those without lymph node metastasis. The receiver operating characteristic curve showed that an intratumoral lymphatic vessel density greater than 2.0 had 83.3% sensitivity and 78% specificity in predicting lymph node metastasis. Analysis of cell immunoreactivity showed cytoplasmic D2-40 positivity in intratumoral and normal tissue in 89.7% and 65.5% of patients, respectively. A strong correlation emerged between grade of cell differentiation and D2-40 immunoreactivity in intratumoral tissue; in particular, 88.9% of tumors with weak podoplanin expression were G1, whereas strong cellular immunoreactivity was detected in 83.3% of G3 patients (P = .003; χ(2) test). A significant correlation was also noted between pattern of reactivity and tumor grade because the basal layer was positive in patients with undifferentiated tumors (100% of G3) and in 72.2% of G1 tumors (P = .021; χ(2) test). D2-40 seems to be a useful marker for the development of node metastasis in squamous cell carcinoma of the penis, although validation in larger series is required to confirm its predictive value.     

BST2 promotes growth and induces gefitinib resistance in oral squamous cell carcinoma via regulating the EGFR pathway

IntroductionGefitinib, well known as a new antitumor agent, has been applied in various cancers such as oral squamous cell carcinoma (OSCC). However, most patients eventually acquire resistance to gefitinib, and the molecular mechanism of gefitinib resistance is not well described. Bone marrow stromal cell antigen 2 (BST2) has been reported to promote tumor cell growth and confer chemotherapy resistance in various cancers. However, the roles of BST2 in OSCC still need to be fully understood.Material and methodsWe determined the expression of BST2 in OSCC tissues using qRT-PCR, immunohistochemistry and western blot. Next, we used MTT assay, flow cytometry and western blot to determine the roles of BST2 in OSCC cell proliferation, cycle progression and apoptosis, respectively. Furthermore, we evaluated the effect of BST2 on gefitinib resistance in OSCC cells and explored the related molecular mechanism.ResultsBST2 expression was up-regulated in OSCC tissues compared with the adjacent normal tissues. BST2 overexpression significantly enhanced OSCC cell proliferation, mediated the cell cycle progression and inhibited cell apoptosis. Additionally, the results showed that BST2 overexpression effectively induced gefitinib resistance in OSCC cells. Subsequent analysis revealed that the underlying mechanism was associated with activation of the EGFR pathway.ConclusionsOur study indicated that BST2 promoted growth and induced gefitinib resistance in OSCC cells, at least partially, through regulating the EGFR pathway. Thus, BST2 could be used as a therapeutic target for gefitinib resistance in OSCC.     

Primary squamous cell carcinoma of the stomach: a case report and literature review

Primary squamous cell carcinoma (SCC) of the stomach is rare. Its pathogenesis is also unclear and there are conflicting reports about it in the past. Only about 100 cases have been reported so far in the literature. The current study discusses a new case of gastric squamous cell carcinoma, from a 50-year-old Chinese male patient diagnosed via subtotal gastrectomy with Roux-en-Y reconstruction and D2 lymphadenectomy. In the stomach, an ulcerated mass in the antrum, measuring 12×8×6 cm, was observed. Further, pathological examination of the resected specimen revealed a well-differentiated SCC. Observations indicated tumor cell invasion into the serosa, and encroachment into perigastric regional lymph node. A follow-up abdominal CT scan three months later revealed tumor invasion into the ascending colon. We assume that this invaded mass was transferred from the gastric squamous cell carcinoma. Interestingly, the patient is still alive.     

ADAM-17 associated with CD44 cleavage and metastasis in oral squamous cell carcinoma

ADAM-17 (a disintegrin and metalloproteinase 17) is a membrane-anchored protein, which can cleave the ectodomain in a variety of transmembrane proteins. In the in vitro experiments with tumor cells, ADAM-17 is reported to cleave CD44, an adhesion molecule that interacts with hyaluronic acid, to promote tumor cell migration. In the present study, we examined ADAM-17 expression and CD44 cleavage in specimens from 50 patients diagnosed to have oral squamous cell carcinoma (SCC). Each specimen was divided into two pieces, one was studied by immunohistochemistry and the other was subjected to a Western blot. By coordinating the results of both analyses, ADAM-17 expression was evaluated to be high in 23 cases (46%). When CD44 cleavage was also studied by immunohistochemical staining as well as with Western blotting, CD44 cleavage was judged to be positive in 29 cases (58%). When the ADAM-17 expression level was compared with the CD44 cleavage state, most of the cases expressing high levels of ADAM-17 (87%) showed positive CD44 cleavage. The level of ADAM-17 expression was significantly correlated to the nodal metastasis and local recurrence in oral SCC. Our findings suggest that ADAM-17 is involved in CD44 cleavage and contributes to tumor progression in oral SCC.     

Expression of cell cycle and apoptosis regulatory proteins in keratoacanthoma and squamous cell carcinoma

Some authors view keratoacanthoma (KA) as a variant of squamous cell carcinoma (SCC), while others consider it a separate entity that must be distinguished from SCC. Involution displayed by KA is an important difference between these two entities. It has been suggested that apoptosis plays a role in the involution process of KA, although the exact trigger for it remains unclear. A hundred and fifty specimens were included in this study, 30 cases for each of the following groups: normal skin (NS), proliferative keratoacanthoma (pKA), regressing keratoacanthoma (rKA), well-differentiated squamous cell carcinoma (wdSCC), and poorly differentiated squamous cell carcinoma (pdSCC). They were immunohistochemically examined for the expression of p53, Ki-67, bak, and bcl-2. Significantly higher p53 and Ki-67 expressions were observed in all tumor lesions examined as compared with NS. There was higher bak expression in KAs compared to NS and a significant reduction of bak expression in pdSCC together with a significant reduction of bak expression in SCCs compared to pKA. Bcl-2 expression was similar in NS and SCCs, but was lower in rKA. We found a significant positive correlation between p53 and Ki-67, p53 and Bak in NS and examined skin tumors. Lower bcl-2 expression in conjunction with higher bak expression in rKA suggests a possible role of these apoptosis-regulating proteins in tumor regression. In contrast to this finding, a steady level of bcl-2 expression in pdSCC combined with lower bak expression levels and a high proliferation rate could contribute to progression and aggressiveness in these tumors. Bak and p53 expression is a sun-related and age-dependent process in NS and skin tumors.     

nm23蛋白在口腔鳞癌Tca8113细胞中的表达

目的:研究nm23蛋白在口腔鳞癌细胞株Tca8113中的表达,探讨其在口腔鳞癌发展中的作用。方法:Western blot法检测nm23蛋白的表达,免疫细胞化学法检测nm23蛋白的表达及其分布,激光扫描共聚焦显微镜观察细胞骨架的变化。结果:nm23蛋白在口腔鳞癌细胞中随着维生素E琥珀酸酯作用时间的延长表达上调,主要分布在细胞质中,细胞骨架的主要成分微丝肌动蛋白逐渐减少,呈碎片状。结论:nm23蛋白可能与口腔鳞癌的发展有关。     

Clinicopathological significance of PTEN and bcl2 expressions in oral squamous cell carcinoma

A high frequency of mutations at the PTEN locus has been noticed in carcinoma of oral. However, the role of PTEN alternations and its association with outcome variables in the genesis of oral carcinoma is not understood fully. The purpose of our study was to examine the impact of PTEN and Bcl2 in the genesis of Squamous cell carcinoma of oral. Total numbers of 60 histopathologically confirmed cases of Squamous Cell Carcinoma and 15 cases of inflammatory lesion of oral specimens were studied. We assessed PTEN and bcl2 overexpression by the use of anti-PTEN and anti-bcl2 antibody through immunohistochemistry as directed by the manufacturer. There was progressive loss of PTEN expression from inflammatory lesion to OSCC (p<0.05). Significant differences were found for PTEN expression between inflammatory lesion and OSCC. The difference in expression pattern of PTEN in gender did not reach statistical significance (p>0.05). The expression of bcl2 was found to be restricted to tumor cells in well and moderately differentiated tumors. The intense expression of bcl2 was observed throughout the tumor cell in poorly differentiated tumors.The Overexpression of bcl2 and loss of PTEN expression were correlated to poor differentiation, lymph node involvement and late stages. Thus, alteration of PTEN and bcl2 is likely an important molecular event in pathogenesis and carcinogenesis of oral carcinoma.     

骨桥蛋白在食管鳞癌中的表达及其临床意义

目的观察骨桥蛋白（OPN）在食管鳞癌组织、癌旁组织和转移淋巴结的表达状况,探讨OPN在食管鳞癌中表达的临床意义。方法运用免疫组化S-P法检测44例食管鳞癌组织、癌旁组织和20例转移淋巴结免疫组化染色。结果OPN在食管癌组织、癌旁组织及转移淋巴结中的表达率分别为86．3％、0％和100％。癌组织中OPN主要表达于肿瘤细胞的细胞浆中。OPN的表达与肿瘤TNM分期、淋巴结转移状态有关,而与肿瘤位置、肿瘤直径、浸润深度及病理学分级无关。OPN在癌组织、癌旁组织及转移淋巴结表达强度亦存在显著性差异。结论食管鳞癌组织中OPN主要由肿瘤细胞产生。OPN与肿瘤的浸润、转移有关,反映了肿瘤的生物学特性。     

Inhibition of cervical lymph node metastasis by marimastat (BB-2516) in an orthotopic oral squamous cell carcinoma implantation model

Activation of matrix metalloproteinase-2 (MMP-2) is a common event in head and neck squamous cell carcinoma. An OSC-19 cell line, derived from human oral squamous cell carcinoma and known to metastasize to cervical lymph nodes, was implanted into the lingual margin of mice. The effect of marimastat (BB-2516), a broad MMP inhibitor, on the suppression of regional cervical lymph node metastasis was evaluated with an orthotopic implantation nude mice model. Marimastat was given immediately after OSC-19 implantation and continuously administered by an osmotic pump. The mice were divided into three groups by marimastat dose; Group A; 0 mg/kg/day, Group B; 30 mg/kg/day, and Group C; 150 mg/kg/day. Twenty-one days after implantation, primary oral tumors and cervical lymph nodes were resected. Cervical lymph node status was microscopically examined. Activation of MMP-2 in primary oral tumor was examined by gelatin zymography. Both cervical lymph node metastasis and activation of MMP-2 were significantly suppressed in Group C (P<0.05). Moreover, the Group C mice had a significantly better survival than group A (P=0.0026). There was a significant difference between Group A and Group C in terms of proliferation of tumor cells by proliferating cell nuclear antigen immunostaining (P=0.0120). These results suggest a positive role for marimastat in the inhibition of MMP-2 activation and prevention of cervical lymph node metastasis in oral squamous cell carcinoma (OSCC). Improvement of survival in patients with OSCC could be expected using adjuvant therapy with marimastat. This revised version was published online in July 2006 with corrections to the Cover Date.     

DNA repair gene ERCC2 polymorphisms and risk of squamous cell carcinoma of the head and neck

Introduction

Genetic aberrations of DNA repair enzymes are known to be common events and to be associated with different cancer entities. Aim of the following study was to analyze the genetic association of single nucleotide polymorphisms (SNP) of the DNA repair genes with the risk of squamous cell carcinoma of the head and neck (HNSCC).

Materials and methods

Genetic variants ERCC2 Lys751Gln (rs13181), ERCC2 Asp312Asn (rs1799793), XRCC1 Arg194Trp (rs1799782); XRCC1 Gln399Arg (rs25487), XRCC1 Arg280His (rs25489) and XRCC3 Thr241Met (rs861539) were analyzed in a primary study group comprising 169 patients with histologically confirmed HNSCC and 463 healthy control subjects. Polymorphisms associated with HNSCC were furthermore analyzed in an independent replication study including 125 HNSCC.

Results

Only the ERCC2 751 Gln/Gln genotype was associated with HNSCC in the primary study (p = 0.033) and in the replication study (p = 0.023), resulting in an overall odds ratio of 0.54 (95% confidence interval 0.35–0.92; p = 0.006).

Conclusion

Carriers of the homozygous ERCC2 751 Gln/Gln genotype may be at lower risk for HNSCC.     

MHC antigen expression in human oral squamous carcinoma cell lines.

This study quantified the constitutive and interferon-gamma (IFN-gamma) stimulated expression of MHC class I (HLA-ABC and beta 2 microglobulin) and class II antigens (HLA-DR, -DP, -DQ) on normal and malignant oral keratinocytes using radioimmunoassay and immunocytochemical techniques. Normal keratinocytes and three of four malignant cell lines (H103, H157, H314) expressed MHC class I antigens constitutively; IFN-gamma increased MHC class I expression with significant changes in normals, H157 and H314. Normal keratinocytes expressed significantly more constitutive MHC class I antigens than H103 and H157 and significantly more IFN-gamma stimulated MHC class I antigens than H103, H157 and H314. MHC class II antigens predominantly were not expressed constitutively on normals, H103 and H157 but, in H314, HLA-DR, -DP and -DQ antigens were demonstrated on 35, 11 and 5 per cent of cells, respectively, and resulted in a non-coordinated pattern of expression (HLA-DR greater than -DP = -DQ). IFN-gamma induced HLA-DR on normals, H103 and H157, whilst HLA-DP and -DQ remained undetectable. In H314, IFN-gamma enhanced HLA-DR, -DP and -DQ (significant increase of HLA-DQ) but the interrelationship between these antigens was maintained (HLA-DR greater than -DP = -DQ). Normal keratinocytes expressed significantly more IFN-gamma stimulated HLA-DR than H103 and H157 but significantly less HLA-DR than H314 under similar experimental conditions. One oral malignant cell line (H191) did not express MHC class I and MHC class II antigens either constitutively or in response to IFN-gamma. The results demonstrate aberrant patterns of MHC expression (absence, enhanced, diminished) in the different malignant oral keratinocyte cell lines.     

胃癌组织中环氧化酶-2、C-met和基质金属蛋白酶-9蛋白的表达及意义

目的:探讨胃癌组织中环氧化酶-2(COX-2)、C-met蛋白和基质金属蛋白酶-9(MMP-9)蛋白表达、相互关系及意义.方法:采用免疫组织化学Envision法检测104例胃癌组织中COX-2、C-met和MMP-9蛋白的表达,并以28例正常胃黏膜组织作为对照.结果:104例胃癌组织中COX-2、C-met、MMP-9蛋白的阳性表达率分别为57.7％、59.6％和63.5％,而在胃正常组织中均呈低表达或不表达,两者差异有统计学意义;三者的表达都与肿瘤浸润深度、临床分期及淋巴结转移呈正相关,而与患者性别、不同分化程度、年龄无差异;COX-2的表达与C-met和MMP-9的表达呈正相关.结论:COX-2、C-met和MMP-9的过表达促进胃癌的浸润转移,3者具有正协同作用.联合检测COX-2、C-met和MMP-9表达,可作为判断胃癌生物学行为的重要指标.