Intraductal pseudopodia in pleomorphic adenoma of parotid gland

Pleomorphic adenoma is the most common salivary gland tumor. Pseudopodia are finger-like projections extending beyond the tumor capsule, seen in pleomorphic adenoma. If not resected completely, these pseudopodia may increase the risk of recurrence after excision of pleomorphic adenoma. While performing a total conservative parotidectomy for the pleomorphic adenoma of the parotid gland, we encountered tumor in the Stensen's duct. On pathological examination, the tumor was not involving the wall of the duct but was passing through the lumen, like a pseudopod. During parotidectomy, the surgeon should inspect the lumen of parotid duct for the presence of any tumor. Pseudopodia of pleomorphic adenoma may extend into the lumen and if not addressed adequately may lead to recurrence of the tumor.

CKS2 affects filopodia formation of A2780 cells through regulating CDC42 alternative splicing / 解放军医学杂志

Objective To study the effect of CKS2 on filopodia formation of A2780 cells through regulating CDC42 alternative splicing. Methods The filopodia were observed after CKS2 of A2780 cells were knocked down by lentivirus-mediated shRNA; the migrating ability of A2780 cells was also measured by wound healing assay; the expression levels of splicing variants CDC42-V1 and CDC42-V2 mRNA was determined by real time PCR after CKS2 knockdown. The expression levels of CKS2, CDC42-V1 and CDC42-V2 mRNA were further measured in each ovarian cancer and normal ovarian samples in the same way. Results The filopodia on A2780 cells obviously decreased, and the migrating ability of A2780 cells was also remarkably reduced after CKS2 knockdown (P<0.05). Meanwhile the expression of CDC42-V1 mRNA decreased and CDC42-V2 mRNA increased after CKS2 knockdown (P<0.05). Real time PCR results showed that the mRNA expression levels of CKS2 and CDC42-V1 were higher in ovarian cancer samples than in normal ovarian tissues; however, the expression level of CDC42-V2 mRNA was lower in ovarian cancer samples than in normal ovarian tissues (P<0.05). ConclusionCKS2 may affect the filopodia formation of A2780 cells through regulating CDC42 alternative splicing, and further affect the migrating ability of A2780 cells.

Noncompetitive antagonists and agonists of glutamate receptor regulate filopodia formation in epidermal cells and melanosome transfer: an experimental study / 中华皮肤科杂志

Objective To investigate the regulatory effect of glutamate signaling pathway on filopodia formation in epidermal cells and on melanosome transfer.Methods Epidermal melanocytes and keratinocytes were isolated from human foreskin and subjected to subculture.After two to three passages of subculture,the melanocytes and keratinocytes were cultured alone or in combination with or without the presence of MK801 (an antagonist of N-methyl-D-aspartic acid (NMDA) receptor) of 100 μmol/L,or NMDA (the activator of NMDA receptor) of 100 μmol/L,for 24 hours.The melanocytes irradiated with UVB at 311 nm served as the control.Scanning electron microscopy was used to observe the appearance of filopodia and dendrites of melanocytes and keratinocytes.Melanosome transfer was visualized under confocal laser scanning microscopy after double immunofluorescent staining.Results Although no obvious changes were observed in the number of dendrites in monocultured melanocytes after treatment with MK801 or NMDA for 24 hours,dendrites became thinner at the terminus and longer with a decrease in the number and length of filopodia after MK801 treatment,but thicker and shorter with an increase in the number and length of filopodia after NMDA treatment compared with untreated monocultured melanocytes.In the coculture system,filopodia were observed between the untreated melanocytes and keratinocytes,and the number of filopodia in melanocytes was larger in the side adjacent to keratinocytes than in the opposite side.Compared with the untreated coculture system,the number of both filopodia connecting melanocytes and keratinocytes and filopodia extending from melanocytes to keratinocytes decreased in the coculture system after treatment with MK801 of 100 μmol/L,but increased after treatment with NMDA of 100 μmol/L,for 24 hours.Melanosomes were found in keratinocytes cocultured with melanocytes without treatment,which were decreased in number after 24-hour treatment with MK801 of 100 μmol/L,but increased in number and even present in keratinocytes nonadiacent to melanocytes after 24-hour treatment with NMDA of 100 μmol/L.Conclusion Glutamate signaling pathway may modulate the transfer of melanosomes from melanocytes to keratinocytes via modulating the appearance of melanocyte dendrites and formation of filopodia.

Docetaxel inhibits the migration and invasion of breast cancer cells by suppressing filopodia formation / 肿瘤

Objective: To investigate the effects of docetaxel and ADM (doxorubicin) on migration, invasion and filopodia formation of breast cancer cells. Methods: Triple-negative breast cancer MDA-MB-231 cells were divided into three groups: blank control group, docetaxel group and ADM group. CCK-8 (cell counting kit-8) assay was used to determine the IC10 (inhibitory concentration of 10%) values of docetaxel and ADM. Abilities of invasion and migration were detected by Transwell assay under IC10 of docetaxel and ADM. The effect of these concentrations on cellular proliferation was assayed by flow cytometry to detect the cell cycle. The rhodamine-phalloidin was used to stain cell cytoskeleton to observe filopodia formation after treatment with these two drugs. Results: The IC10 values of docetaxel and ADM in MDA-MB-231 cells were 1.0 ng/mL and 0.5 μg/mL, respectively. These two concentrations had no effects on cellular proliferation and cell cycle (P > 0.05). Docetaxel (1.0 ng/mL) could inhibit migration and invasion of tumor cells more effectively than ADM (0.5 μg/mL). Docetaxel inhibited filopodia formation of triple-negative breast cancer cells more effectively with a statistical significance. Conclusion: Docetaxel can obviously inhibit the migration and invasion of breast cancer cells as compared with ADM, which may be associated with suppression of filopodia formation by these agents. Copyright © 2013 by TUMOR.

Roles of glutamate signaling pathway in melanin transfer / 中华皮肤科杂志

Objective To investigate the roles of glutamate signaling pathway in melanin transfer.MethodsEpidermal melanocytes and keratinocytes were isolated from human foreskin tissue followed by purification and primary culture.Immunofluorescence microscopy was conducted to observe the intracellular distribution of N-methy-D-aspartate receptor 1 (NMDAR1) and NMDAR2A in melanocytes.Some melanocytes were classified into 4 groups to be pretreated with MK801 (the NMDAR antagonist dizocilpine maleate) at 100μmol/L for 5 minutes followed by treatment with NMDA(an NMDAR agonist) at 100 μmol/L (MK801-pretreated group 1),pretreated with MK801 at 100 μmol/L for 1 hour followed by treatment with NMDA at 100μmol/L (MK801-pretreated group 2),treated with MK801 at 100 μmol/L for 5 minutes (MK801 group),treated with NMDA at 100 μmol/L for 5 minutes (NMDA group),respectively,then,confocal microscopy was performed to measure the intracellular calcium (Ca2+) concentration of the melanocytes.The distribution of β-tubulin was visualized by confocal microscopy in melanocytes treated with MK801 at 100 μmol/L for 24 hours.Some melanocytes and keratinocytes were cocultured with or without MK801 at 100 μmol/L for 24 or 48 hours,then,scaning microscopy was carried out to observe the junction structure between melanocytes and keratinocytes,and alkali method coupled with spectrophotometric analysis to determine melanin content in keratinocytes.Results The intracellular calcium concentration of melanocytes was decreased by MK-801,but increased by NMDA at 100 μmol/L,and the increase was blocked by the pretreatment with MK-801 for 5 minutes or 1 hour.After incubation with MK-801 at 100 μmol/L for 24 hours,a more intense staining for β-tubulin was observed around the nuclei of melanocytes.There was a significant reduction in the number of filopodia on the surface of and between melanocytes and keratinocytes after treatment with MK-801 at 100 μmol/L for 48 hours.Also,the content of melanin(represented as the absorbance value at 375 nm) transferred from melanocytes into keratinocytes was statistically reduced in coculture system treated with MK-801 at 100 μmol/L compared with that without treatment (0.158 ± 0.003 vs.2.203 ± 0.006,t =6.323,P ＜ 0.01 ).Conclusions The glutamate signaling pathway exerts a regulatory effect on intracellular calcium concentration of distribution of β-tubulin in,filopodia formation of melanocytes and melanin transfer between melanocytes and keratinocytes.

Role of Cdc 42 gene in the suppression of filopodia formation induced by non-steroidal anti-inflammatory drugs in breast cancer cells / 肿瘤

Objective: To investigate the effect of cell division cycle 42 (Cdc 42) gene on the formation of filopodia suppressed by non-steroidal anti-inflammatory drugs (NSAIDs), and to explore the probable signal transduction pathway involving Cdc 42 in the inhibition effects on migration and invasion abilities of breast cancer cells induced by NSAIDs. Methods: MCF-7 cells were divided into four groups: blank control group, NS-398 (100 μmol/L)-treated group, cyclooxygenase-2 (Cox-2) small interfering RNA (siRNA)-transfected group and the negative siRNA-transfected group. The expressions of Cox-2 and Cdc42 mRNAs were detected by real-time fluorogentic quantitative PCR(RFQ-PCR), and the expressions of Cox-2 and Cdc42 proteins were measured by Western blotting. Actin-tracker Green fluorescent probe was used to examined the morphology of filopodias in MCF-7 cells. The invasion ability of MCF-7 cells was detected by using the Martrigel-coated Transwell. Results: The filopodias in MCF-7 cells disappeared in the NS-398-treated group, and the invasion ability of MCF-7 cells was also significantly decreased in this group compared with that in the blank control group (P0.05), and the difference was also not seen in the expression of Cdc42 mRNA or protein between these two groups (P>0.05). The active-Cdc42 level was significantly decreased in the NS-398-treated group compared with that in the blank control group (P<0.05). The filopodias in the Cox-2 siRNA-transfected group disappeared, and the invasion ability of MCF-7 cells transfected with Cox-2 siRNA was significantly decreased compared with that in the negative siRNA-transfected group (P<0.05). The active-Cdc42 level was also significantly decreased in MCF-7 cells transfected with Cox-2 siRNA compared with those transfected with negative siRNA (P<0.05). Conclusion: NSAIDs can suppress the invasion ability of breast cancer cells. This effect may be achieved by inhibiting the activity of Cox-2, decreasing the expression level of active-Cdc42, and suppressing the formation of filopodias.