• 대한두경부종양학회지
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• 제13권2호
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• pp.169-179
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• 1997

서론 : Laminin의 수용기로 알려진 Integrin $\alpha6\beta4$의 세포내 표현 정도는 편평상피암을 위시한 여러 악성종양의 전이능력 및 예후와 밀접한 상관관계가 없다고 알려져 있다. 이 Integrin은 Laminin과 같은 세포와 리간드와 결합하면 상피세포의 기저막 지주 구조물인 hemidesmosome의 세포체질 요소(cytoskeletal element)와 연관되어 그 결과 세포의 기저막과 세포내 케라틴을 연결하는 역할을 한다. Integrin $\alpha6\beta4$는 구조적으로 다른 많은 integrin들과 달리 $\beta$4의 세포질내 영역(cytoplasmic domain)이 특징적으로 크다. 이 세포질내 영역 $\beta$4 integrin의 기능은 아직 밝혀지지 않고 있으나 아마 세포 성장의 신호전달 및 악성종양의 특징인 침윤 전이에 관련할 것으로 보아지고 있다. 재료 및 방법: 저자들은 우선 $\beta$4 integrin의 wild type s-DNA와 $\beta$4 세포질내 영역(cytoplasmic domain) 및 $\beta$4의 tyrosine 인산화 반응 부위가 각각 결손된 c-DNA를 PCR을 통하여 합성하여 pRc/CMV 벡터에 삽입한 후 원래 $\beta$4 integrin의 발현이 결집된 인간 방광암 세포에 Calcium phosphate precipitation 방법으로 주입(transfection)시켜 형질변환된 세포를 면역형광법, Flow cytometry 및 Immunoprecipitation 방법으로 클로닝하여 wild type $\beta$4-full length(Clone FL), truncated $\beta$4-cytoplasmic domain(C1one CD), 및 mutated $\beta$4-tyrosine phosphorylation site (Clone M)을 얻었다. 암 세포의 부착 및 침투 능력의 기능적 연구로 모노 클로날 항체와 fibronectin, laminin, Matrigel을 단백질 기질로 사용하였으며 결과 비교를 위하여 pRc/CMV 벡터만 주입시켰던 클로운과 방광암 세포주를 $\beta$4 integrin 음성 대조군으로 또한 이 Integrin의 높은 발현을 보이는 두경부 편평상피암 세포주를 양성 대조군으로 이용하였다. 결과 : 세포부착능력에 있어서 온전한 $\beta$4 cytoplasmic domain이 존재하는 클로운이 laminin에 강한 부착능력을 보였으나 fibronectin의 부착정도는 $\beta$4 integrin의 표현정도와 관계없이 모든 클로운에서 비슷하였다. Matrigel을 투과하는 암세포 침윤 능력에서는 $\beta$4 integrin의 표현이 존재하는 클로운들이 투과 능력이 높았으나 세포외 리간드가 없는 control membrane을 사용하였을 때와 비교하여 투과능력의 차이를 보이지 않았다. 결론 : 유전자 주입(transfection) 방법으로 integrin의 다양한 클로운의 합성이 가능하여 이 Integrin의 암 세포의 부착 및 침투 능력에서의 기능을 규명 할 수 있게 한다. $\beta$4 integrin은 편평상피 암세포의 부착에 있어서 세포외 리간드 laminin과 특이 결합하여 부착 능력을 높이는 중요한 역할을 하며 편평상피 암세포의 침투에 있어서는 $\beta$4 integrin의 표현이 침투 능력을 높이는 역할을 하나 이때에는 laminin과 같은 리간드와의 특이 결합에 의존하지는 않는 것으로 사료된다.

• Archives of Pharmacal Research
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• 제18권6호
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• pp.376-380
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• 1995

Monocyte adhesion involves specific cell surface receptors, integrins and results in cell differentiation. We have studied expression and regulation of integrin .${\alpha}_5{\beta}_1$ during differntiation of U937 as in vitro model. To determine expression of integrin ${\alpha}_5{\beta}_1$ during differentiation of U937 as in vitro model. To determine expression of integrin ${\alpha}_5{\beta}_1$ genes by RT-PCR (reverse transcription and polymerase chain reaction) method. We determined expression of integrin ${\alpha}_5{\beta}_1$ genes by RT-PCE (reverse transcription and polymerase chain reaction) method. We found that expression of integrin .alpha.5.betha.1 was greatly increased during PMA-induced differentiation of U937 cells and also found that PMA-induced expression of integrin ${\alpha}_5{\beta}_1$ was inhibited by colchicine, microtubule depoly merizing agent. These results indicate that microtubular integrity is associated with expression of integrin. ${\alpha}_5{\beta}_1$ during PMA-induced differentiation of U937 cells.

• International Journal of Oral Biology
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• 제32권3호
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• pp.93-101
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• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권3호
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• pp.143-154
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• 2013

Purpose: This study was to find efficacy of integrin alpha2 (${\alpha}_2$) and epidermal growth factor receptor (EGFR) as tumor marker of oral squamous cell carcinoma (SCC) and clarify the selective cell death effect of anti-integrin ${\alpha}_2$ and anti-EGFR on SCC cells, additionally testify conjugated gold nanoparticles (GNP) with air plasma for selective cell death of oral SCC. Methods: Expression of integrin ${\alpha}_2$, EGFR on human SCC cells (SCC25) were examined by western blot. SCC25 cells were treated with anti-integrin ${\alpha}_2$, anti-EGFR and analysed by Hemacolor staining, immunoflorescence staining, FACS flow cytometry. Conjugated GNP with integrin ${\alpha}_2$, EGFR antibody were treated by air plasma on SCC cells. Results: Integrin ${\alpha}_2$ and EGFR were over-expressed on SCC25 cells than normal lung WI-38 cells. The cell viability rate of SCC25 cells treated with anti-integrin ${\alpha}_2$, anti-EGFR was lower than WI-38 cells. The concentration changes of nucleus, releasing cytochrome c and apoptosis inducing factor (AIF) from mitochondria to cytosol were observed. The changes of proteins related with apoptosis were observed. Increase of bax, bcl-xL, activation of caspase-3, -7, -9, and fragmentation of PARP, DFF45 and decrease of lamin A/C in SCC25 cells were observed. In FACS, increase of sub-$G_1$ and S phase was observed. Cell cycle related proteins, Such as cyclin D1, cyclin dependent kinase (CDK) 4, cyclin A, cyclin E, CDK 2, p27 were decreased. After SCC25 cells treated with conjugatged GNP-Integrin ${\alpha}_2$, GNP-EGFR, additionally air plasma, the cell death rate was significantly increased. Conclusion: Integrin ${\alpha}_2$, EGFR were over-expressed in oral SCC cells. Anti-integrin ${\alpha}_2$, anti-EGFR in SCC25 cells induced apoptosis selectively. When GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR were treated with air plasma on SCC25 cells, cancer cells were died more selectively. GNP-anti integrin ${\alpha}_2$, GNP-anti EGFR with air plasma could be treatment choice of oral SCC.

• Asian Pacific Journal of Cancer Prevention
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• 제14권6호
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• pp.3891-3895
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• 2013

The purpose of this study was to evaluate the association of expression of ${\alpha}5{\beta}1$-integrin with clinicopathologic features and prognosis in cervical cancer. Levels of ${\alpha}5{\beta}1$-integrin in normal cervical mucosa and cervical cancer tissue were detected with immunohistochemistry. Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance. ${\alpha}5{\beta}1$-integrin expression was detected in 84.6% (143/169) cervical cancer samples, significantly different from that in normal cervical mucosa (P < 0.05). Positive expression rates of ${\alpha}5{\beta}1$-integrin in patients with poor histologic differentiation, lymph node metastasis, and recurrence were elevated. Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expression of ${\alpha}5{\beta}1$-integrin revealed a highly significant difference in human cervical cancer cases (P < 0.05), suggesting that overexpression of ${\alpha}5{\beta}1$-integrin is associated with a worse prognosis.The ${\alpha}5{\beta}1$-integrin promotes angiogenesis and associates with lymph node metastasis, vascular invasion and poor prognosis of cervical cancer. The current study indicated that ${\alpha}5{\beta}1$-integrin may be an independent prognostic factor for cervical cancer patients.

• BMB Reports
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• 제47권12호
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• pp.655-659
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• 2014

Integrin-mediated cell adhesion is important for development, immune responses, hemostasis and wound healing. Integrins also function as signal transducing receptors that can control intracellular pathways that regulate cell survival, proliferation, and cell fate. Conversely, cells can modulate the affinity of integrins for their ligands a process operationally defined as integrin activation. Analysis of activation of integrins has now provided a detailed molecular understanding of this unique form of "inside-out" signal transduction and revealed new paradigms of how transmembrane domains (TMD) can transmit long range allosteric changes in transmembrane proteins. Here, we will review how talin and mediates integrin activation and how the integrin TMD can transmit these inside out signals.

• Journal of Yeungnam Medical Science
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• 제15권1호
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• pp.55-66
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• 1998

사람과 동일한 증상을 나타내는 동물 모델이 없는 신증후출혈열의 병리 기전을 이해하기 위하여 in vitro culture system을 이용하였다. 신증후출혈열의 주된 병변이 혈관내피세포외에 섬유아세포가 많이 존재하는 신세뇨관 간질 및 폐간질임을 기초로 하여 계태아와 Mongolian gerbil의 섬유아세포에서 fibronectin에 대한 수용체인 ${\alpha}_5{\beta}_1$, integrin에 대한 항체를 처리하여 한탄바이러스 감염에 대한 영향을 관찰하였다. 초대 배양하여 사용한 계태아 섬유아세포 및 MGF 모두 한탄바이러스가 잘 감염되었으나 계태아 섬유아세포에 비하여 MGF에서 바이러스의 증식이 더 우수하였다. 계태아 섬유아세포와 MGF에서 ${\alpha}_5{\beta}_1$, integrin에 대한 항체 처리 5일 후 바이러스의 N 단백의 역가는 항체를 처리하지 않은 대조군에 비하여 각각 32.6%, 72.6%로 virion의 역가는 26.8%, 28.7%로 감소하여 두 세포에서 모두 감염력을 가진 바이러스의 양은 거의 동일하게 감소 되었다. 또한 ${\alpha}_5$ subunit와 ${\beta}_1$, subunit에 대한 항체를 MGF 세포에 처리한 후 바이러스의 N단백의 역가는 65.2%, 59.7%로 ${\alpha}_5{\beta}_1$ integrin에 대한 항체 처리하였을 때(72.6%)와 거의 유사하게 감소하였고 감염력을 가진 바이러스의 양도 26.5%, 29.4%로 감소하여 ${\alpha}_5{\beta}_1$ integrin에 대한 항체 처리시(28.7%)와 거의 유사하게 감소하였다. 이러한 결과는 ${\alpha}_5{\beta}_1$ integrin이 한탄바이러스에 대한 수용체로써 작용할 가능성을 시사하였으며 또다른 기전으로는 ${\alpha}_5{\beta}_1$ integrin의 차단에 의한 이차적인 영향으로 한탄바이러스의 증식에 커다란 영향을 미치는 것을 생각할 수 있었다.

• Journal of Korean Neurosurgical Society
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• 제57권5호
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• pp.329-334
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• 2015

Objective : To comparatively investigate the expression of several integrins in specimens of human bone metastases and degenerative bone tissue. Methods : Degenerative cancellous tissue was obtained from a sample of human degenerative spine. Thirteen human specimens were obtained from metastatic spine tumors, whose primary cancer was colon cancer (n=3), hepatocellular cancer (n=3), lung cancer (n=4), and breast cancer (n=3). The expression of vimentin and integrins ${\alpha}v$, ${\beta}1$, and ${\beta}3$ was assessed in metastatic and degenerative specimens by immunohistochemistry and real-time reverse transcription-polymerase chain reaction (qRT-PCR). Results : Immunohistochemical staining showed that vimentin and integrin ${\alpha}v$ was broadly expressed in all tissues examined. By contrast, integrin ${\beta}1$ was weakly expressed only in 38.4% (5/13) of tissues. Integrin ${\beta}3$ was consistently negative in all cases examined. qRT-PCR analysis showed that vimentin gene expression was higher in all metastatic specimens, as compared to degenerative bone. The gene expression of integrin ${\alpha}v$ in breast specimen was significantly higher than others (p=0.045). The gene expression of integrin ${\beta}1$ was also higher in all metastatic specimens than in degenerative bone tissue. The gene expression of integrin ${\beta}3$ was variable. Conclusion : Spinal metastatic tumors have mesenchymal characteristics such as increased expression of vimentin. The increased expression of integrin ${\alpha}v$ and ${\beta}1$ in spine metastatic tumors suggests that adhesive molecules such as integrin may have implications for the prevention of spine metastasis.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.92-101
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• 2020

The cyclic Arg-Gly-Asp (cRGD) peptide is well-known as a binding molecule to the integrin α_vβ₃ receptor which is highly expressed on activated endothelial cells and new blood vessels in tumors. Although numerous results have been reported by the usage of cRGD peptide-based ligands for cancer diagnosis and therapy, the distinct mechanisms, and functions of cRGD-integrin binding to cancer cells are still being investigated. In this study, we evaluated the internalization efficacy of different types of cRGD peptides (monomer, dimer and tetramer form) in integrin α_vβ₃ overexpressing cancer cells. Western blot and flow cytometric analysis showed U87MG expresses highly integrin α_vβ₃, whereas CT-26 does not show integrin α_vβ₃ expression. Cytotoxicity assay indicated that all cRGD peptides (0-200 µM) had at least 70-80% of viability in U87MG cells. Fluorescence images showed cRGD dimer peptides have the highest cellular internalization compare to cRGD monomer and cRGD tetramer peptides. Additionally, transmission electron microscope results clearly visualized the endocytic internalization of integrin α_vβ₃ receptors and correlated with confocal microscopic results. These results support the rationale for the use of cRGD dimer peptides for imaging, diagnosis, or therapy of integrin α_vβ₃-rich glioblastoma.

• Biomolecules & Therapeutics
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• 제25권3호
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• pp.321-328
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• 2017

Steroid sulfatase (STS) is an enzyme responsible for the hydrolysis of aryl and alkyl sulfates. STS plays a pivotal role in the regulation of estrogens and androgens that promote the growth of hormone-dependent tumors, such as those of breast or prostate cancer. However, the molecular function of STS in tumor growth is still not clear. To elucidate the role of STS in cancer cell proliferation, we investigated whether STS is able to regulate the integrin signaling pathway. We found that overexpression of STS in HeLa cells increases the protein and mRNA levels of integrin ${\beta}1$ and fibronectin, a ligand of integrin ${\alpha}5{\beta}1$. Dehydroepiandrosterone (DHEA), one of the main metabolites of STS, also increases mRNA and protein expression of integrin ${\beta}1$ and fibronectin. Further, STS expression and DHEA treatment enhanced phosphorylation of focal adhesion kinase (FAK) at the Tyr 925 residue. Moreover, increased phosphorylation of ERK at Thr 202 and Tyr 204 residues by STS indicates that STS activates the MAPK/ERK pathway. In conclusion, these results suggest that STS expression and DHEA treatment may enhance MAPK/ERK signaling through up-regulation of integrin ${\beta}1$ and activation of FAK.