Modulatory effects of interferon-gamma on the fibronectin receptor function of squamous cell carcinoma cells in vitro.

We previously showed that the in vivo invasion of a squamous cell carcinoma induced by the intradermal injection of tumor cells was significantly delayed after the IFN-gamma-producing gene transfer to tumor cells. With respect to the mechanism of the delayed invasion, it was suggested that the IFN-gamma might inhibit the adhesion of the cells to extracellular matrices (ECM) and the subsequent locomotion. Thus, we examined the effect of IFN-gamma on the adhesion of Pam-T cells to ECM. The attachment of Pam-T cells to fibronectin (FN) was significantly higher than that to laminin (LN), collagen type I (COL I) or collagen type IV (COL IV) substrata. The attachment to FN was significantly enhanced specifically by the IFN-gamma-treatment of the cells, although the attachment to LN, COL I or COL IV was not altered by IFN-gamma. Neither IFN-alpha nor IFN-beta had any effect on the attachment of Pam-T cells to FN. When Pam-T cells were treated with IFN-gamma together with a neutralizable anti-IFN-gamma antibody, this enhancement was completely abolished. Moreover, the attachment of IFN-gamma-treated Pam-T cells as well as non-treated cells to FN was blocked by the synthetic peptide Arg-Gly-Asp-Ser (RGDS), but not by the control peptide Arg-Gly-Glu-Ser. Based on these results, we conclude that IFN-gamma specifically enhances the adhesiveness of Pam-T cells to FN substrata by the modulation of integrin activity.     

5-ALA-PDT对人皮肤鳞状细胞癌A431细胞的抑制作用

目的:确定5-ALA-PDT对人皮肤鳞状细胞癌A431细胞的抑制作用。方法:用5-ALA与A431细胞共同孵育,经630 nln红光照射后,采用MTF法检测细胞生长的抑制率,确定培育时间、5-ALA浓度及光照剂量对皮肤鳞状细胞癌A431细胞的抑制作用。结果:当光照剂量为80 J/cm~2和5-ALA浓度为3.2 mmol/L,5-ALA与A431细胞共同孵育120 min时,抑制率最大。结论:5-ALA-PDT对体外培养的A431细胞的增殖有明显抑制作用。     

p27及skp2在皮肤鳞状细胞癌和Bowen病中的表达

p27是新发现的细胞周期调控因子,S相激酶相关蛋白(skp2)参与p27的降解,我们采用免疫组化方法对皮肤鳞状细胞癌和Bowen病组织中的p27和skp2的表达进行检测.     

Effects of cytochalasin B on human malignant melanoma cells and squamous cell carcinoma cells in vitro.

Human malignant melanoma cells and human squamous cell carcinoma cells were treated with cytochalasin B (CB) in vitro and observed with light and electron microscopes. When spindle-shaped melanoma cells were treated with CB, they rounded up and their submembranous microfilaments (mf) (6 nanometers thick) vanished totally. After being released from CB after treatment for 10 days, they became flat and the submembranous mf reappeared to a nearly normal extent. Squamous cell carcinoma cells, when treated with CB, did not round up and the submembranous mf did not disappear. These results suggest that (i) submembranous microfilaments are not essential to make and keep certain types of cells round and (ii) the responses of cells to cytochalasin B are quite different in different cells.     

Liposome-entrapped contact inhibitory factor: transfer of capacity for density-dependent growth to melanoma cells

Contact inhibitory factor (CIF) is a growth inhibitor obtained from conditioned culture medium of a contact-inhibited line of hamster melanocytic cells, which reversibly restores density-, anchorage-, and serum-dependent growth to melanoma cells. The usefulness of liposomes as carriers for CIF was investigated in vitro. The stability of liposomes prepared both with and without CIF was demonstrated by measuring the rate of efflux of a K2CrO4 marker. Anionic multilamellar lipid vesicles (7 phosphatidylcholine:2 dicetyl phosphate:1 cholesterol) prepared with CIF-containing material and separated from unentrapped CIF by gel filtration on Sepharose 2B, showed retarded leakage of a K2CrO4 marker (half-efflux at 77 h) when compared with identical liposomes lacking CIF (half-efflux at 40 h). When added to subconfluent cultures of hamster melanoma cells, liposome-entrapped CIF restored contact-inhibited growth. Compared with aqueous solutions of CIF, liposome-CIF effects were characterized by longer latency and more sustained duration. The ability of CIF-bearing liposomes to effectively restore density-dependent growth in vitro should facilitate in vivo studies of the effects of this potent growth inhibitor on melanoma and other neoplasms.     

槲皮黄酮通过Sphk2抑制人皮肤鳞状细胞癌A431细胞的增殖

目的：研究槲皮黄酮（Quercetin, Qu）对人皮肤鳞状细胞癌A431细胞增殖活性的影响。方法：采用CCK8法、Western blot实验和流式细胞术检测不同浓度下（10、50、100、200 μg/mL）A431细胞活力、增殖及凋亡相关指标;Western blot检测Qu对A431细胞中Sphk2信号通路的影响。结果：10、50、100、200 μg/mL Qu作用96 h后,细胞OD值分别为（0.654±0.098）、（0.527±0.089）、（0.412±0.076）、（0.309±0.054）;细胞活力分别为（81.3±4.6）%、（56.3±4.9）%、（37.4±4.2）%、（19.4±3.6）%;细胞凋亡率分别为（6.43±1.09）%、（14.77±1.26）%、（21.30±1.36）%、(29.84±1.26)%。Qu呈浓度依赖性的抑制细胞中Sphk2蛋白表达,且Qu+Sphk2 mimics组细胞活力明显高于于Qu,细胞凋亡率明显低于Qu组(Ps<0.05)。结论：Qu可能通过抑制Sphk2信号通路降低人皮肤鳞状细胞癌细胞的增殖活性。     

Increased Fas ligand expression by T cells and tumour cells in the progression of actinic keratosis to squamous cell carcinoma

BACKGROUND: In the counterattack model of tumorigenesis, it has been proposed that tumours develop resistance to attack from Fas ligand (FasL)-expressing cytotoxic T cells by downregulating Fas (immune escape), while at the same time upregulating FasL expression to induce apoptosis in Fas-expressing T cells (counterattack). OBJECTIVES: The aim of this study was to examine Fas and FasL expression on tumour cells and infiltrating T cells during the progression of actinic keratoses (AK), the benign precursor lesion, to squamous cell carcinoma (SCC). PATIENTS AND METHODS: Samples of AK (n = 20) and SCC (n = 20) were collected from immunocompetent patients attending dermatology clinics. Double-label immunohistochemistry was performed on frozen sections using mouse monoclonal antibodies to Fas or FasL, simultaneously with a rabbit polyclonal antibody to either CD3 or cytokeratin, markers of T cells and keratinocytes, respectively. Cell densities and the optical density of tumour Fas expression were measured using image analysis. RESULTS: FasL-expressing T cells were observed in nine of 19 SCCs, compared with three of 20 AKs (P < 0.05). FasL-expressing tumour cells were found in nine of 18 SCCs, compared with only one of 20 AK specimens (P < 0.005). There was no difference in the number of Fas-expressing T cells infiltrating AK and SCC. Fas expression by keratinocytes, measured by optical density, was lower in SCC (range 0.1-40, median 17) compared with AK (range 4-62, median 25) (P < 0.05). CONCLUSIONS: These results suggest that the greater numbers of FasL-expressing T cells infiltrating into SCC compared with AK are targeting Fas-expressing tumour cells. As AK cells progress to SCC, they subvert this T-cell-mediated killing of tumour cells by downregulating their Fas expression (immune escape). Furthermore, tumour cells upregulate their expression of FasL, possibly as a counterattack measure to induce apoptosis in the increased number of tumour-infiltrating T cells. Thus changes in Fas/FasL-mediated interactions between T cells and tumour cells occur during the progression of AK into SCC.     

Preferential binding of monocytes and Leu 2+T lymphocytes to interferon-gamma treated cultured skin endothelial cells and keratinocytes

Summary Recombinant gamma interferon (r-IFN-) increases the adherence of peripheral blood mononuclear leukocytes (PBMLs) to cultured keratinocytes and cutaneous microvascular endothelial cells (MECs). To determine which specific type of PBMLs bound to these r-IFN- treated cells, we performed immunophenotyping on the adherent PBMLs. The adherent PBMLs were detached from the r-IFN- treated keratinocytes and MECs by adding EDTA, and collected by cytocentrifugation, followed by immunocytochemical staining using a panel of monoclonal antibodies. Our results reveal that the relative adherent population of PBMLs was composed of approximately 60%–70% monocytes and 18%–24% Leu 2+T lymphocytes (T-cytotoxic/suppressor) which preferentially bound to r-IFN- treated keratinocytes and MECs. There was some lesser binding by Leu 3+ lymphocytes (T-helper/inducer); approximately 8%, and no binding of B lymphocytes. Since r-IFN- also induced HLA-DR expression in keratinocytes and MECs, these in vitro data suggest that r-IFN- may play an important role in the immunobiology of diverse skin diseases such as graft vs host disease, lichen planus, and other inflammatory dermatoses, because the keratinocytes express HLA-DR and the predominant T-cell subset in the epidermis is Leu 2+ (over the Leu 3+T cell) in all of these conditions. These results represent a direct attempt to explain in situ immunophenotypic mononuclear leukocyte subset distribution patterns by using r-IFN- and purified cultured cells such as keratinocytes and MECs. We propose that IFN-, by both increasing the adherence of PBMLs, and promoting selective binding of monocytes and Leu 2+T lymphocytes to both keratinocytes and MECs, may be important in regulating PBML localization and recirculation in the skin.This work was partially supported by NIH Grant AM 35390 (BJN) and the Joseph Drown Foundation (MAK)     

COX-2抑制剂NS398对人鳞状细胞癌Tca8113细胞株生长和凋亡的影响

目的 探讨COX-2抑制剂NS398对鳞状细胞癌细胞Tca8113生长及凋亡的影响。方法 细胞培养加入NS398作用后,采用噻唑蓝（MTT） 法观察NS398 对Tca8113细胞增殖的影响,流式细胞仪及透射电镜研究NS398对Tca8113细胞周期和凋亡的作用。结果 MTT比色法显示NS398能抑制Tca8113细胞的生长,呈浓度和时间依赖性。流式细胞仪检测结果显示NS398干预细胞出现典型的亚二倍体"凋亡峰";G0 /G1期细胞比例升高,S期和G2 /M期比例下降。电镜下见典型的凋亡形态学改变。结论COX-2抑制剂NS398在体外可通过诱导凋亡有效抑制Tca8113细胞的生长。     

C-erbB-1及C-erbB-2癌基因蛋白在外阴鳞癌及癌前病变中的表达

目的：探讨原癌基因Ｃ ｅｒｂＢ １、Ｃ ｅｒｂＢ ２和外阴癌发生的关系。方法：应用免疫组化ＡＢＣ法检测了１３２例外阴病变中原癌基因Ｃ ｅｒｂＢ １和Ｃ ｅｒｂＢ ２的表达。结果：两种癌基因在正常皮肤、外阴各型营养不良、不典型增生和鳞癌中的表达不同（Ｐ＜０．０５）。在各级鳞癌中表达则相反。结论：提示Ｃ ｅｒｂＢ １和Ｃ ｅｒｂＢ ２在外阴鳞状上皮增生、癌变和鳞癌生长的不同阶段均有不同作用。     

Langerhans cells, antigen presentation, and the diversity of responses to chemical allergens.

Respiratory and contact chemical allergens provoke differential immune responses in mice, stimulating preferentially T helper-2 (TH2) and TH1 cells, respectively. In an attempt to discover whether such differences are effected at the level of antigen handling and presentation we have examined the effect of topical exposure to trimellitic anhydride (TMA), a respiratory allergen, and 2,4-dinitrochlorobenzene (DNCB), a contact allergen, on Langerhans cell (LC) MHC class II (Ia) expression. Neither chemical caused a significant change in LC size. As measured by analytical flow cytometry, exposure to DNCB resulted in a time-dependent increase in LC Ia expression that exceeded 160% of control values within 24 h. Exposure to concentrations of TMA that caused an equivalent activation of draining lymph nodes failed to affect Ia expression by LC. Application of sodium lauryl sulfate at concentrations that caused edema also failed to influence LC Ia. These data demonstrate that TMA and DNCB exert differential effects on epidermal LC, possibly indicative of differences in antigen handling.     

Modulation of type-IV procollagen and laminin production in A431 human squamous epidermoid carcinoma cells by 12-O-tetradecanoylphorbol-13-acetate (TPA) and epidermal growth factor (EGF)

Summary The effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) and epidermal growth factor (EGF) on type-IV-procollagen (basement-membrane collagen) and laminin synthesis, turnover, and secretion was studied in human A431 squamous epidermoid carcinoma cells. Type-IV procollagen and laminin were biochemically and immunologically identified in the medium and cell extracts using immunoprecipitation followed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. EGF or TPA produced a sixfold increase in type-IV-procollagen and laminin secretion within 2 h; this was accompanied by a three-to fourfold increase in the levels of cell-associated type-IV procollagen and laminin, respectively. The level of type-IV-procollagen and laminin synthesis and secretion remained elevated for at least 16 h after the administration of either EGF or TPA. A combination of EGF and TPA was more effective than either agent alone in promoting the secretion of laminin but not of type-IV procollagen. EGF and/or TPA did not, however, produce a selective increase in the synthesis of collagen and laminin, since total protein synthesis was also increased to the same degree by these agents. As dtermined by labeling and chase studies, neither EGF nor TPA had any appreciable effect upon type-IV-procollagen or laminin degradation. These results indicate that the synthesis of components associated with the basement membrane in A431 cells (i.e., type-IV procollagen and laminin) can be rapidly modulated by EGF and a tumor promoter, i. e., TPA. The increase in extracellular-matrix-protein production precedes any effects of these agents on cell growth. However, changes in cell shape in response to either EGF or TPA may trigger the increase in the synthesis and secretion of type-IV procollagen and laminin.     

Characterization of in vitro culture of HIV-negative Kaposi’s sarcoma-derived cells. In vitro responses to alfa interferon

We established long-term cultures from skin tumors of nine patients suffering from classical Kaposi’s sarcoma (KS). Spindle cells obtained after enzymatic digestion were cultured on gelatin- or fibronectin-coated flasks in DMEM with 15% fetal calf serum, aFGF and heparin. Immunohistochemical staining was positive for MHC class I, laminin, type IV collagen, vimentin, α smooth muscle actin (20–40% of cells), caldesmon (20%), calponin (20–40%) and smooth muscle myosin (20–40%), and was negative for common leukocyte antigen, CD4, LFA1, CD34 and cytokeratin. Around 20% of cells up to the third passage in culture expressed the endothelial markers CD36, BMA 120 but were negative for UEA and Fc von Willebrand. Smooth muscle proteins were detected with immunoblotting. Using the polymerase chain reaction, human herpes virus 8 (HHV8) sequences were detected in primary cultures of three out of seven cell lines but were rapidly lost during in vitro passaging. KS-derived cells did not proliferate in serum-free medium, had a normal karyotype and did not grow in soft agar medium. Tumors formed in nude mice injected with KS-derived cells. The tumors were composed of mouse cells and were highly vascularized. Our results suggest that KS-derived cells are heterogeneous: the majority of cells have either a smooth muscle cell or a fibroblastic phenotype. Another minor cell compartment was composed of endothelium-derived cells. KS cells do not possess the characteristics of transformed cells in vitro and may be composed of polyclonal activated cells. Recombinant α interferon (rIFN) slightly inhibited the growth of KS-derived cells and increased the expression of MHC class I antigens. While cells were resistant to natural killer (NK) cell-mediated cytotoxicity, they became sensitive to rIFN-primed NK cells. Thus, the antitumor potential of rIFN against KS in vivo could result from immunomodulatory rather than from direct antiproliferative effects. Received: 4 July 1996     

Phosphatidylinositol-specific-phospholipase C cleaves urokinase plasminogen activator receptor from the cell surface and leads to inhibition of pemphigus-IgG-induced acantholysis in DJM-1 cells, a squamous cell carcinoma line

We showed previously that pemphigus IgG enhanced both the activity of urokinase plasminogen activator (uPA) in cultured cells and the expression of its receptor (uPAR) on uPA-binding keratinocytes. In the present study, to clarify whether uPAR and uPA-activated plasmin are actually involved in the blistering process after pemphigus IgG binding to the cell surface, we examined the effects of the following on uPAR expression and on cell-cell detachment in DJM-1 cells, a squamous cell carcinoma line: (i) phosphatidylinositol-specific phospholipase C (PI-PLC) - which releases uPAR from the membrane surface into the culture medium by cleaving the glycosylphosphatidylinositol anchor thus inhibiting uPAR activity, and (ii) uPA inhibitors (tranexamic acid, aprotinin, p-aminobenzonic acid and dexamethasone). Preincubation with PI-PLC decreased dramatically the pemphigus IgG-induced uPAR expression in a dose-dependent manner, and inhibited pemphigus IgG-induced cell-cell detachment at 10 microg/mL. On the other hand, tranexamic acid (15 mM) inhibited pemphigus IgG-induced cell-cell detachment without reduction of uPAR expression, although aprotinin, p-aminobenzonic acid and dexamethasone failed to alter either of these parameters. Although uPAR expression on the pemphigus IgG-bound cell surface and uPA activation may contribute significantly to the pathogenesis of acantholysis in pemphigus, the mechanisms are complicated and should be defined further.     

Activation of mitochondrial apoptosis pathways in cutaneous squamous cell carcinoma cells by diclofenac/hyaluronic acid is related to upregulation of Bad as well as downregulation of Mcl-1 and Bcl-w

Actinic keratosis (AK) is characterized by high prevalence and the risk to proceed to squamous cell carcinoma (SCC). Cyclooxygenase-2 (COX-2)-mediated prostaglandin E2 (PGE (2) ) synthesis has been reported in AK and SCC, and the COX inhibitor diclofenac in hyaluronic acid (diclofenac/HA) was approved for AK therapy. Its mode of action, however, remained to be unravelled. In the present study, diclofenac resulted in reduced PGE (2) levels in apoptosis-sensitive cutaneous SCC cell lines (SCL-II, SCC-12, SCC-13) whereas no PGE (2) and no COX-2 expression was detectable in a SCC cell line resistant to apoptosis induction (SCL-I). Activation of mitochondrial apoptosis pathways was evident in SCC cells owing to loss of the mitochondrial membrane potential and release of the mitochondrial factors cytochrome c and apoptosis-inducing factor. Characteristic proapoptotic changes at the level of Bcl-2 proteins occurred in sensitive cells, as upregulation of Bad and downregulation of Mcl-1 and Bcl-w. In contrast, Bad was already high, and Mcl-1 and Bcl-w were already low in resistant SCL-I, even without treatment, which may be explained by the lack of PGE (2) . An antiapoptotic downregulation of proapoptotic Bcl-2 proteins Noxa and Puma was, however, also seen in SCL-I, suggesting here pathways independent of COX-2. The regulations of Mcl-1 and Bad were also reproduced in SCC cells by the more selective COX-2 inhibitor celecoxib, thus further underlining the specific role of COX-2. The findings illuminate the mode of action of diclofenac/HA in SCC cells as well as principles of their resistance, which may allow further adaptation and improvement of the new therapy.     

毛囊混合细胞植入胶原/壳聚糖多孔支架诱导裸鼠毛发生长及支架内形成血管样结构

目的 探讨利用毛囊混合细胞植入胶原,壳聚糖多孔支架内重建毛囊的可行性与支架内血管形成状态.方法 用注射法将体外培养的C57BL/6J近交系乳鼠背部皮肤毛囊混合细胞接种至胶原,壳聚糖多孔支架,培养2周后,将含毛囊混合细胞胶原/壳聚糖多孔支架植入裸鼠皮下,肉眼观察裸鼠背部毛发形成情况.6周后取移植区皮肤组织经10%甲醛固定后行组织学观察(HE染色).结果 移植至裸鼠皮下5周后,裸鼠背部在含毛囊混合细胞的胶原,壳聚糖多孔支架移植区皮肤出现毛发,丰长,6周后取皮肤组织作HE染色发现有分化成熟的毛囊形成,且支架内有血管样结构形成.而空白胶原/壳聚糖多孔支架移植区皮肤未发现毛生长,组织检杳也未发现有毛囊形成,且只有在支架表浅部位有少黑血管样结构形成.结论 毛囊混合细胞植入胶原/壳聚糖多孔支架内可诱导裸鼠毛发的形成,促进支架血管样结构的形成.