• 제목/요약/키워드: Lamellipodia

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Cellular Protrusions - Lamellipodia, Filopodia, Invadopodia and Podosomes - and their Roles in Progression of Orofacial Tumours: Current Understanding

  • Alblazi, Kamila Mohamed Om;Siar, Chong Huat
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권6호
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    • pp.2187-2191
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    • 2015
  • Background: Protrusive structures formed by migrating and invading cells are termed lamellipodia, filopodia, invadopodia and podosomes. Lamellipodia and filopodia appear on the leading edges of migrating cells and function to command the direction of the migrating cells. Invadopodia and podosomes are special F-actin-rich matrix-degrading structures that arise on the ventral surface of the cell membrane. Invadopodia are found in a variety of carcinomatous cells including squamous cell carcinoma of head and neck region whereas podosomes are found in normal highly motile cells of mesenchymal and myelomonocytic lineage. Invadopodia-associated protein markers consisted of 129 proteins belonging to different functional classes including WASP, NWASP, cortactin, Src kinase, Arp 2/3 complex, MT1-MMP and F-actin. To date, our current understanding on the role(s) of these regulators of actin dynamics in tumors of the orofacial region indicates that upregulation of these proteins promotes invasion and metastasis in oral squamous cell carcinoma, is associated with poor/worst prognostic outcome in laryngeal cancers, contributes to the persistent growth and metastasis characteristics of salivary gland adenoid cystic carcinoma, is a significant predictor of increased cancer risk in oral mucosal premalignant lesions and enhances local invasiveness in jawbone ameloblastomas.

Pristimerin Inhibits Breast Cancer Cell Migration by Up-regulating Regulator of G Protein Signaling 4 Expression

  • Mu, Xian-Min;Shi, Wei;Sun, Li-Xin;Li, Han;Wang, Yu-Rong;Jiang, Zhen-Zhou;Zhang, Lu-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1097-1104
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    • 2012
  • Background/Aim: Pristimerin isolated from Celastrus and Maytenus spp can inhibit proteasome activity. However, whether pristimerin can modulate cancer metastasis is unknown. Methods: The impacts of pristimerin on the purified and intracellular chymotrypsin proteasomal activity, the levels of regulator of G protein signaling 4 (RGS 4) expression and breast cancer cell lamellipodia formation, and the migration and invasion were determined by enzymatic, Western blot, immunofluorescent, and transwell assays, respectively. Results: We found that pristimerin inhibited human chymotrypsin proteasomal activity in MDA-MB-231 cells in a dose-dependent manner. Pristimerin also inhibited breast cancer cell lamellipodia formation, migration, and invasion in vitro by up-regulating RGS4 expression. Thus, knockdown of RGS4 attenuated pristimerin-mediated inhibition of breast cancer cell migration and invasion. Furthermore, pristimerin inhibited growth and invasion of implanted breast tumors in mice. Conclusion: Pristmerin inhibits proteasomal activity and increases the levels of RGS4, inhibiting the migration and invasion of breast cancer cells.

미세아교세포의 진동 거동의 연구 (Oscillatory behavior of microglial cells)

  • 박은영;조영빈;고웅현;박진성;신현정
    • 한국가시화정보학회지
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    • 제19권1호
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    • pp.74-80
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    • 2021
  • Cells regulate their shapes and motility by sensing the cues from the internal and external microenvironment. Under different circumstances, microglia, the brain resident immune cells, undergo dynamic phenotypic changes, one of which is a remarkable periodic oscillatory migration in vitro. However, very little is known about the kinematic and dynamic perspectives of this oscillatory behavior. In this study, we tracked the changes in cell morphology and nuclear displacement, and visualized the forces using traction force microscopy (TFM). By correlation analyses, we confirmed that the lamellipodia formation preceded the nuclear translocation. Moreover, traction, developed following lamellipodia formation, was found to be localized and fluctuated at two ends of the oscillating cells. Taken together, our results imply that oscillatory microglial cells feature a viscoelastic migration, which will contribute to the field of cell mechanics.

Rac1 inhibition protects the kidney against kidney ischemia/reperfusion through the inhibition of macrophage migration

  • You Ri Park;Min Jung Kong;Mi Ra Noh;Kwon Moo Park
    • The Korean Journal of Physiology and Pharmacology
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    • 제27권3호
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    • pp.257-265
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    • 2023
  • Kidney ischemia/reperfusion (I/R) injury, a common cause of acute kidney injury (AKI), is associated with the migration of inflammatory cells into the kidney. Ras-related C3 botulinum toxin substrate 1 (Rac1), a member of the Rho family of small GTPase, plays an important role in inflammatory cell migration by cytoskeleton rearrangement. Here, we investigated the role of Rac1 on kidney I/R injury and macrophage migration. Male mice were subjected to either 25 min of bilateral ischemia followed by reperfusion (I/R) or a sham operation. Some mice were administrated with either NSC23766, an inhibitor of Rac1, or 0.9% NaCl (vehicle). Kidney damage and Rac1 activity and expression were measured. The migration and lamellipodia formation of RAW264.7 cells, mouse monocyte/macrophage, induced by monocyte chemoattractant protein-1 (MCP-1, a chemokine) were determined using transwell migration assay and phalloidin staining, respectively. In sham-operated kidneys, Rac1 was expressed in tubular cells and interstitial cells. In I/R-injured kidneys, Rac1 expression was decreased in tubule cells in correlation with the damage of tubular cells, whereas Rac1 expression increased in the interstitium in correlation with an increased population of F4/80 cells, monocytes/macrophages. I/R increased Rac1 activity without changing total Rac1 expression in the whole kidney lysates. NSC23766 administration blocked Rac1 activation and protected the kidney against I/R-induced kidney damage and interstitial F4/80 cell increase. NSC23766 suppressed monocyte MCP-1-induced lamellipodia and filopodia formation and migration of RAW 264.7 cells. These results indicate Rac1 inhibition protects the kidney against I/R via inhibition of monocytes/macrophages migration into the kidney.

F-actin cytoskeleton이 Jurkat T 림파구의 microvilli 형성에 미치는 영향 (Involvement of F-Actin Cytoskeleton for Microvilli Formation of Jurkat T Lymphocyte)

  • 이재설;김해영;손기애;김지은;문경미;김광현;최은봉;이종환
    • 생명과학회지
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    • 제21권10호
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    • pp.1401-1406
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    • 2011
  • 면역세포는 외부 병원체 감염, 자연적 순환에 대하여 형태변화를 수반한다. T세포는 염증, 면역 감시, 이동, 그리고 혈관통과를 위해 uropod, filopodia, lamellipodia, 및 microvilli를 생산한다. 짧고 손가락 처럼 생긴 microvilli는 순환하고 있는 포유동물 면역세포 표면을 덮고 있다. 단핵세포와 호중구의 세포표면은 많이 다른데 membrane ruffle을 함유하고 있다. 본 연구는, T세포의 microvilli에 대하여 actin cytoskeleton과의 연관성에 대하여 탐구하였다. Actin 파괴자인 cytochalasin D 처리 후 SEM관찰을 통해서, Jurkat T세포의 microvilli를 보면 빠르게 사라지는 것을 알 수 있었다. 이와는 대조적으로 RhoA의 activator인 PMA는 LIMK와 cofilin 신호 전달을 통해서 microvilli 두께가 확장되는 것을 관찰 하였다. 또한, cytochalasin D 처리는 EL4 T세포의 극성을 사라지게 하는 것으로 보아 F-actin은 T세포의 극성 유지에도 영향을 미친다. 이상의 결과는 Actin cytoskeleton은 T세포에서 microvilli와 극성 유지에 관여하고 있는 것을 제시한다.

v-Crk Induces Rac-dependent Membrane Ruffling and Cell Migration in CAS-deficient Embryonic Fibroblasts

  • Sung, Bong Hwan;Yeo, Myoung Gu;Oh, Hye Jin;Song, Woo Keun
    • Molecules and Cells
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    • 제25권1호
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    • pp.131-137
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    • 2008
  • Crk-associated substrate (CAS) is a focal adhesion protein that is involved in integrin signaling and cell migration. CAS deficiency reduces the migration and spreading of cells, both of which are processes mediated by Rac activation. We examined the functions of v-Crk, the oncogene product of the CT10 virus p47gag-crk, which affects cell migration and spreading, membrane ruffling, and Rac activation in CAS-deficient mouse embryonic fibroblasts (CAS-/- MEFs). CAS-/- MEFs showed less spreading than did CAS+/+ MEFs, but spreading was recovered in mutant cells that expressed v-Crk (CAS-/-v-Crk MEF). We observed that the reduction in spreading was linked to the formation of membrane ruffles, which were accompanied by Rac activation. In CAS-/- MEFs, Rac activity was significantly reduced, and Rac was not localized to the membrane. In contrast, Rac was active and localized to the membrane in CAS-/-v-Crk MEFs. Lamellipodia protrusion and ruffle retraction velocities were both reduced in CAS-/- MEFs, but not in CAS-/-v-Crk MEFs. We also found that microinjection of anti-gag antibodies inhibited the migration of CAS-/-v-Crk MEFs. These findings indicate that v-Crk controls cell migration and membrane dynamics by activating Rac in CAS-deficient MEFs.

Antimetastatic effect of fucoidan against non-small cell lung cancer by suppressing non-receptor tyrosine kinase and extracellular signal-related kinase pathway

  • Nareenath Muneerungsee;Supita Tanasawet;Wanida Sukketsiri
    • Nutrition Research and Practice
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    • 제17권5호
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    • pp.844-854
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    • 2023
  • BACKGROUND/OBJECTIVES: Fucoidan, a polysaccharide content in brown algae, has been reported to inhibit the growth of cancer cells. The present study aimed to investigate the suppression effects of fucoidan on A549 non-small cell lung cancer cells migration. MATERIALS/METHODS: The anti-migratory activity of fucoidan in A549 cells was examined by wound healing assay and phalloidin-rhodamine staining in response to fucoidan (0-100 ㎍/mL) treatment for 48 h. Western blot analysis was performed to clarify the protein expressions relevant to migratory activity. RESULTS: Fucoidan (25-100 ㎍/mL) significantly suppressed A549 cells migration together with reduced the intensity of phalloidin-rhodamine which detect filopodia and lamellipodia protrusions at 48 h of treatment. The protein expression indicated that fucoidan significantly suppressed the phosphorylation of focal adhesion kinase (FAK), Src, and extracellular signal-related kinase (ERK). In addition, the phosphorylation of p38 in A549 cells was found to be increased. CONCLUSIONS: Our data conclude that fucoidan exhibits anti-migratory activities against lung cancer A549 cells mediated by inhibiting ERK1/2 and FAK-Src pathway.

Distinctive Features of Advancing Breast Cancer Cells and Interactions with Surrounding Stroma Observed Under the Scanning Electron Microscope

  • Jaafar, Hasnan;Sharif, Sharifah Emilia Tuan;Murtey, Mogana Das
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1305-1310
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    • 2012
  • Breast cancer cells undergo transformation when they spread into surrounding tissues. Studies have shown that cancer cells undergo surface alterations and interact with the surrounding microenvironment during the invasion process. The aim of the present study was to analyse these cancer cell surface alterations and interactions of cancer cells and stroma. Twenty 1-methyl-1-nitrosourea-induced breast cancer samples taken from five rats were fixed in McDowell-Trump fixative and then washed in 0.1 M phosphate buffer. The samples were then treated with osmium tetroxide before being washed in distilled water and subsequently dehydrated through graded ethanols. The dehydrated samples were immersed in hexamethyldisilazane (HMDS), then following removal of excess HMDS, the samples were air dried at room temperature in a dessicator. The dried samples were mounted onto specimen stubs and coated with gold coater before being viewed under a scanning electron microscope. We detected the presence of membrane ruffles on the surface of cancer cells and the formation of unique surface membrane protrusions to enhance movement and adhesion to the surrounding stroma during the process of invasion. Advancing cancer cells demonstrated formation of lamellipodia and invadopodia. The stroma at the advancing edge was desmoplastic with many collagen fibres laid down near the cancer cells. Our data suggest that all of these abnormalities could act as hallmarks of invasiveness for breast cancer.

Astaxanthin induces migration in human skin keratinocytes via Rac1 activation and RhoA inhibition

  • Ritto, Dakanda;Tanasawet, Supita;Singkhorn, Sawana;Klaypradit, Wanwimol;Hutamekalin, Pilaiwanwadee;Tipmanee, Varomyalin;Sukketsiri, Wanida
    • Nutrition Research and Practice
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    • 제11권4호
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    • pp.275-280
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    • 2017
  • BACKGROUND/OBJECTIVES: Re-epithelialization has an important role in skin wound healing. Astaxanthin (ASX), a carotenoid found in crustaceans including shrimp, crab, and salmon, has been widely used for skin protection. Therefore, we investigated the effects of ASX on proliferation and migration of human skin keratinocyte cells and explored the mechanism associated with that migration. MATERIAL/METHOD: HaCaT keratinocyte cells were exposed to $0.25-1{\mu}g/mL$ of ASX. Proliferation of keratinocytes was analyzed by using MTT assays and flow cytometry. Keratinocyte migration was determined by using a scratch wound-healing assay. A mechanism for regulation of migration was explored via immunocytochemistry and western blot analysis. RESULTS: Our results suggest that ASX produces no significant toxicity in human keratinocyte cells. Cell-cycle analysis on ASX-treated keratinocytes demonstrated a significant increase in keratinocyte cell proliferation at the S phase. In addition, ASX increased keratinocyte motility across the wound space in a time-dependent manner. The mechanism by which ASX increased keratinocyte migration was associated with induction of filopodia and formation of lamellipodia, as well as with increased Cdc42 and Rac1 activation and decreased RhoA activation. CONCLUSIONS: ASX stimulates the migration of keratinocytes through Cdc42, Rac1 activation and RhoA inhibition. ASX has a positive role in the re-epithelialization of wounds. Our results may encourage further in vivo and clinical study into the development of ASX as a potential agent for wound repair.

치주인대세포의 부착과 전개에 관한 형태학적 관찰 (THE MORPHOLOGICAL OBSERVATION OF HUMAN PERIODONTAL LIGAMENT CELLS ATTACHMENT AND SPREADING ON THE SURFACE OF SLIDE GLASS)

  • 이진미;서조영;박준봉
    • Journal of Periodontal and Implant Science
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    • 제23권1호
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    • pp.97-108
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    • 1993
  • 치주조직의 초기치유과정에서 가장 중요한 역할을 하는 치주인대세포의 부착과 전개에 대한 형태학적 관찰을 위하여 교정치료 목적으로 발거된 치아로부터 치주인대조직을 채취하여 초기배양하고 동일한 양($5{\times}10^3ml$)의 치주인대 세포를, 2장의 유리가 포함된 35mm 배양접시에 접종한 후, $CO_2$ 배양기에서 배양하여 세포배양개시후 10분, 30분, 90분, 6시간, 12시간, 24시간의 시간간격에 따라서 광학위상차현미경과 주사전자현미경을 이용하여 세포부착과 전개양상을 관찰한 결과 다음과 같은 결과률 얻었다. 10분간 배양한 세포는 구형을 나타내었으며, 기질측의 세포질이 박판엽상으로 확장되어 기질에 부착개시한 양상이 보였다. 배양 30분 후 판모양의 세포돌기인 박판상돌기에서 세사상돌기롤 내어 부착하는 양상이 관찰되었고, 세포표면은 소기포와 미세융모로 덮여 있었다. 90분간 배양한 세포에서 핵은 세포의 중심부에 위치하였고 세포질이 방사선상으로 확장되어 부착된 양상을 보였으며, 미전개된 세포중심부에는 미세융모와 소기포로 덮여져 있었다. 배양 6시간 후 세포는 신장된 양상을 보였고 타원형의 핵이 관찰되었다. 세포의 양극에서 박판상돌기가 관찰되었고 다시 세사상돌기가 분지되는 양상을 보였는데 이 돌기의 말단부는 팽대되어 기질에 부착하였다. 12시간 배양한 후의 치주인대 세포는 뚜렷한극성화를 보이면서 길게 신장된 양상을 나타내었다. 배양 24시간 경과후 신장된 양상의 핵이 세포의 한쪽극에 치우쳐 있었으며, 세포외형은 길게 신장된 방추상의 형태가 관찰되었다.

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