小鼠黑色素瘤B16F10-Red细胞株的建立与生物学特性分析

目的:构建表达香菇珊瑚红色荧光蛋白(discosomasp red fluorescent protein,DsRed)的小鼠黑色素瘤B16F10-Red细胞株,并检测其生物学特性.方法:用GenEscortTMⅡ转染试剂将pDsRed质粒导入小鼠黑色素瘤B16F10细胞,G418加压培养联合极限稀释法建立稳定、高水平表达DsRed的单克隆细胞系.FCM检测B16F10和B16F10-Red细胞的细胞周期.比较B16F10-Red和B16F10细胞的克隆球形成能力和小鼠体内致瘤能力.结果:稳定表达DsRed的小鼠黑色素瘤B16F10-Red细胞株基本保持了其亲代细胞的特征,能在C57BL/6小鼠腹部皮下形成肿瘤并继续生长和转移.结论:B16F10-Red细胞株构建成功,其移植瘤模型成瘤率和转移情况同B16F10肿瘤相比无明显差别.     

Nitric oxide-mediated regulation of hypoxia-induced B16F10 melanoma metastasis

Tumour hypoxia is associated with resistance to therapy and with increased invasion and metastatic potential. Recent studies in our laboratory have shown that the hypoxic up-regulation of tumour cell invasiveness and chemoresistance is in part due to reduced nitric oxide (NO) signaling. Using B16F10 murine melanoma cells, we demonstrate here that the increased metastatic potential associated with exposure to hypoxia is mediated by a reduction in cGMP-dependent NO-signaling. Pre-incubation of B16F10 cells in hypoxia (1% vs. 20% O(2)) for 12 hr increased lung colonization ability by over 4-fold. This effect of hypoxia on metastasis was inhibited by co-incubation with low concentrations of the NO-mimetic drugs glyceryl trinitrate (GTN) and diethylenetriamine NO adduct (DETA/NO). In a manner similar to hypoxia, pharmacological inhibition of NO synthesis resulted in a significant increase in lung nodule formation, an effect that was prevented by co-incubation with GTN. An important NO-signaling pathway involves the activation of soluble guanylyl cyclase and the consequential generation of cGMP. Culture in the presence of a non-hydrolysable cGMP analogue (8-Br-cGMP) abrogated the hypoxia-induced lung nodule formation, suggesting that the effects of NO on metastasis are mediated via a cGMP-dependent pathway. These findings suggest that a novel mechanism whereby hypoxia regulates metastatic potential involves a downstream inhibition of cGMP-dependent NO signaling.     

Pentoxifylline impedes migration in B16F10 melanoma by modulating Rho GTPase activity and actin organisation

Cancer cell migration is a hallmark of metastatic cascade and compounds that can intervene in this process are clinically important. Pentoxifylline (PTX), a methyl xanthine derivative, inhibits B16F10 melanoma lung homing by inhibiting F10 invasion, MMP secretion and adhesion to matrix components. However, its effect on B16F10 migration remained unexamined, which we investigated in the present study. PTX significantly inhibits F10 migration in scratch wound assay. Elevation in cAMP levels inhibits F10 migration and PTX mediated inhibition of the process was found to be, in part, due to an increase in cellular cAMP levels. PTX induces Protein Kinase A (PKA) activity and PKA inhibitor partly reversed its effects on F10 motility. RhoA and Rac1 GTPases induce B16F10 motility and PTX was found to inhibit migration by affecting these molecules. Stress fibres and lamellipodial protrusions reduced significantly. This was accompanied with inhibition in RhoA and Rac1 membrane localisation. A stark inhibition in RhoA-GTP bound form was also observed. Taken together, the results indicate that PTX, through its phosphodiesterase action, inhibits RhoGTPases and associated actin organisation in B16F10 melanoma, thereby inhibiting cell motility.     

Antiproliferative and Antiproteolytic activity of Pentoxifylline in cultures of B16F10 Melanoma cells

Purpose: Pentoxifylline (PTX), a methyl xanthine derivative is widely used as a haemorheological agent in the treatment of peripheral vascular disease. In the present study, we investigated the in vitro effects of PTX on B16F10 melanoma cell proliferation, adhesion and secretion of Matrix metalloproteinases. Methods: The toxic range of PTX was evaluated using MTT test and colony formation assay. The cell cycle study of PTX treated cells was carried out using flow cytometric analysis. Adhesion assay of pretreated melanoma cells was carried out on extracellular matrix (ECM) substrates. The relative levels and activity of matrix metalloprotienase-9 (MMP-9) and MMP-2 were determined by gelatin zymography and western blotting. Results: Pentoxifylline significantly inhibited the in vitro proliferation of B16F10 cells in a concentration dependent manner and displayed an IC₅₀ of 15.2 mM. Non-cytotoxic concentration of 1–3 mM of PTX for an exposure of 24 h demonstrated significant changes in cell morphology. A significant inhibition in G1-S phase transition was observed on PTX treatment. Pretreated F10 cells showed inhibition in adhesion to ECM components and markedly inhibited the secretion of MMP-9 and MMP-2 gelatinases. Conclusion: The results suggest that PTX even at non-toxic pharmacological concentrations acts as an effective antiproliferative agent with significant antiproteolytic and antiadhesive effects.     

Paclitaxel Combined with Ticagrelor Inhibits B16F10 and Lewis Lung Carcinoma Cell Metastasis

It is widely accepted that tumor metastasis is the dominant factor leading to cancer-related death. Tumor metastasis is mediated by cell invasion, blood circulation and lymphatic circulation. Paclitaxel, as a common anti-tumor drug and a mitotic inhibitor, promotes microtubule assembly and inhibits microtubule depolymerization. In addition, ticagrelor, an anti-platelet drug, is used to treat acute coronary syndrome. Increasing numbers of studies have reported that platelets can facilitate tumor metastasis. Therefore, inhibiting the effects of platelets can serve as a novel therapeutic strategy for cancer. To explore the effect of anti-tumor and anti-platelet drugs on tumor progression, we chose paclitaxel and ticagrelor. Interestingly, the results demonstrated that paclitaxel and ticagrelor could not only suppress the proliferation, migration and invasion of B16F10 and LLC cells, but they could also prevent tumor metastasis to the lungs. Furthermore, the inhibitory effect of paclitaxel and ticagrelor was more apparent when both drugs were used in combination. Collectively, the current study demonstrated that the combination of paclitaxel and ticagrelor could be considered as a potential anti-tumor therapy approach.     

GnRH/M2融合蛋白致敏DC疫苗对黑色素瘤B16F10细胞移植瘤的抑制

目的:制备促性腺激素释放激素(gonadotropin releasing hormone,GnRH)与M2的融合蛋白(GnRH/M2),研究由该融合蛋白致敏而成的DC疫苗对黑色素瘤B16F10细胞小鼠移植瘤的抑制作用.方法:构建表达载体pET28a-ansB-C-GnRH3-hinge-MVP-M2质粒,该质粒转化的工程菌在乳糖的诱导下,融合蛋白ansB-C-GnRH3-hinge-MVP-M2以包涵体形式表达,经超声破碎、洗涤和乙醇分级沉淀纯化后,通过酸水解将蛋白多肽GnRH3-hinge-MVP-M2释放出来,并通过DEAE-52阴离子交换层析进行分离.将此融合多肽致敏DC获得DC疫苗.构建黑色素瘤B16F10细胞小鼠移植瘤模型,按接种疫苗不同,分为:环磷酰胺组(CTX)、GnRH/M2融合蛋白致敏DC组(GDC)、肿瘤细胞裂解物致敏DC组(BDC)、GnRH/M2融合蛋白致敏DC+环磷酰胺组(GDCTX)、肿瘤细胞裂解物致敏DC+环磷酰胺组(BDCTX)和生理盐水组(NS),观察GnRH/M2疫苗对模型小鼠的移植瘤生长、CTL杀伤能力和T细胞增殖的作用.结果:成功构建pET28a-ansB-C-GnRH3-hinge-MVP-M2质粒并高效表达融合蛋白.GDC组移植瘤生长明显慢于NS组(P＜0.05),且与BDC组相似(P ＞0.05);GDCTX组抑瘤效果虽进一步提高,但与CTX组相比差异无统计学意义(P＞0.05).各实验组对B16F10细胞的杀伤作用和对T细胞增殖作用均优于阴性对照组(P ＜0.05或P＜0.01),且GDC组与BDC组间差异不显著(P＞0.05).结论:初步证明融合多肽GnRH/M2致敏的DC疫苗能有效抑制黑色素瘤B16F10细胞小鼠移植瘤的生长.     

B16-F10-luc-G5黑色素瘤细胞生物学特性的研究

目的：探讨B16-F10-luc-G5黑色素瘤细胞的生物学特性.方法：倒置荧光显微镜下连续观察B16-F10-luc-G5细胞生长动态.流式细胞术检测冻存复苏后、培养基漂浮细胞、胰酶消化损伤后的细胞死亡率以评价其对实验损伤的耐受性.1×104/孔B16-F10-luc-G5细胞按1∶2梯度稀释至0.78×102/孔,加入底物荧光素后检测其生物发光特性.Babl/C和C57 bl/6雄性小鼠各10只接种该细胞,目测肿瘤生长速度和活体成像监测Babl/C小鼠移植瘤生长动态以评价其成瘤特性.结果：B16-Fl0-luc-G5细胞生长动态符合典型B16-F10细胞特性,无自发及激发荧光.B16-F10-luc-G5细胞冻存、漂浮细胞及对数生长期细胞消化后死亡率分别为23.8％、35.8％和4.8％.B16-F10-luc-G5细胞数与实测平均光子数之间存在线性回归关系,检测光子数可反映细胞数目.两组小鼠移植成瘤率均为100％,平均肿瘤出现时间差异显著（t =9.05,P＜0.05）,移植瘤病理符合B16黑色素瘤典型生长特点;活体成像监测可灵敏监测移植瘤生长动态.结论：B16-F10-luc-G5细胞具有生长快、对各种实验操作耐受性好、标记生物发光基因易追踪等优点,且其一般特性与B16-F10细胞基本相同,是肿瘤学研究良好的实验材料.     

Cyclopalladated compounds as chemotherapeutic agents: antitumor activity against a murine melanoma cell line

Palladacycle compounds obtained from N, N-dimethyl-1-phenethylamine (dmpa), phenyl-2-pyridinyl-acetylene and 1-phenyl-3-N, N-dimethylamine-propine, respectively, were complexed to 1, 2 ethanebis (diphenylphosphine) (dppe) ligand to synthesize antitumor cyclopalladated complexes that were tested in vitro and in vivo against syngeneic B16F10-Nex2 murine melanoma cells of low immunogenicity implanted subcutaneously in mice. Complexes were not toxic to mice injected 3 times i.p. with as much as 60 microM/animal/week. Of 3 cyclopalladated complexes that were inhibitory in vitro at low concentrations (<1.25 microM), complex 7a was the most active in vivo, delaying tumor growth and prolonging animal survival. In vitro, binucleate complex 7a caused a collapse of respiratory activity with an abrupt decrease of extracellular acidification on short incubation (up to 100 min), followed by DNA degradation after 24 hr. The apoptosis-like reaction to this Pd-complex was not accompanied by increased levels of caspases 1 and 3. Complex 7a bound to a bacterial plasmid DNA, causing late conformational changes after 24 hr. Two other complexes with different C, N-cycles were also apoptotic and 2 binucleated ones were inactive. These results introduce the palladacycle-dppe complexes as promising antitumor drugs with exquisite structural specificities and for action in vivo and in vitro.     

Intrathecal ACNU treatment of B16 melanoma leptomeningeal metastasis in a new athymic rat model

Summary To evaluate new cytotoxic drugs for intrathecal treatment we developed an experimental model of leptomeningeal metastasis by intracisternal injection of 10⁴B16-F10 melanoma cells in nude rats. One hour in vitro incubation with 20 g/ml ACNU (area under the drug concentration-time curve = 1200 gxmin/ml) induced a 4-log kill of B16 melanoma cells. A single or repeated non-toxic dose of 1 mg/kg was injected into the cisterna magna of rats inoculated with tumor (area under the drug concentration-time curve assuming an even cerebrospinal fluid distribution > 7000 gxmin/ml). Median survival free of symptoms was 16 days (range 14–27) for controls (n = 9) and 18 days (range 17–23) for rats treated with ACNU on day 4 (n = 9). Animals treated both on day 2 and 8 (n = 8) developed symptoms on day 21 (range 13–35). Neurological symptoms and neuropathological examination in animals with increased survival indicated local suppression of tumor growth in the cisterna magna but increased spinal seeding and mass growth. From these results and the available pharmacokinetic data on ACNU it is concluded that bolus injection of ACNU — although locally effective — is not a sufficient treatment of widespread leptomeningeal metastasis. An increased therapeutic efficacy might be achieved by ventriculolumbar perfusion.     

Pericyte dysfunction due to Shb gene deficiency increases B16F10 melanoma lung metastasis

Intravasation, vascular dissemination and metastasis of malignant tumor cells require their passage through the vascular wall which is commonly composed of pericytes and endothelial cells. We currently decided to investigate the relative contribution of these cell types to B16F10 melanoma metastasis in mice using an experimental model of host Shb gene (Src homology 2 domain-containing protein B) inactivation. Conditional inactivation of Shb in endothelial cells using Cdh5-CreERt2 resulted in decreased tumor growth, reduced vascular leakage, increased hypoxia and no effect on pericyte coverage and lung metastasis. RNAseq of tumor endothelial cells from these mice revealed changes in cellular components such as adherens junctions and focal adhesions by gene ontology analysis that were in line with the observed effects on leakage and junction morphology. Conditional inactivation of Shb in pericytes using Pdgfrb-CreERt2 resulted in decreased pericyte coverage of small tumor vessels with lumen, increased leakage, aberrant platelet-derived growth factor receptor B (PDGFRB) signaling and a higher frequency of lung metastasis without concomitant effects on tumor growth or oxygenation. Flow cytometry failed to reveal immune cell alterations that could explain the metastatic phenotype in this genetic model of Shb deficiency. It is concluded that proper pericyte function plays a significant role in suppressing B16F10 lung metastasis.     

Fatty acid synthase inhibition with Orlistat promotes apoptosis and reduces cell growth and lymph node metastasis in a mouse melanoma model

Fatty acid synthase (FASN) is the enzyme responsible for the endogenous synthesis of the saturated fatty acid palmitate. In contrast to most normal cells, malignant cells depend on FASN activity for growth and survival. In fact, FASN is overexpressed in a variety of human cancers including cutaneous melanoma, in which its levels of expression are associated with a poor prognosis and depth of invasion. Here, we show that the specific inhibition of FASN activity by the antiobesity drug Orlistat or siRNA is able to significantly reduce proliferation and promote apoptosis in the mouse metastatic melanoma cell line B16-F10. These results prompted us to verify the effect of FASN inhibition on the metastatic process in a model of spontaneous melanoma metastasis, in which B16-F10 cells injected in the peritoneal cavity of C57BL/6 mice metastasize to the mediastinal lymph nodes. We observed that mice treated with Orlistat 48 hr after the inoculation of B16-F10 cells exhibited a 52% reduction in the number of mediastinal lymph node metastases, in comparison with the control animals. These results suggest that FASN activity is essential for B16-F10 melanoma cell proliferation and survival while its inactivation by Orlistat significantly reduces their metastatic spread. The chemical inhibition of FASN activity could have a potential benefit in association with the current chemotherapy for melanoma.     

Punarnavine Induces Apoptosis in B16F-10 Melanoma Cells by Inhibiting NF-kB Signaling

The objective of this study was to assess the effect of Punarnavine, an alkaloid isolated from Boerhaaviadiffusa, on apoptosis in B16F-10 melanoma cells. Treatment of B16F-10 melanoma cells with nontoxicconcentrations of Punarnvine resulted in the presence of apoptotic bodies and DNA fragmentation in a dosedependent manner. Cell cycle analysis and TUNEL assays also confirmed the observation. The apoptotic genesp53 and caspase-3 were found upregulated in Punarnavine treated cells, whereas the antiapoptotic gene Bcl-2was downregulated. The inhibited nuclear translocation of NF-κBp65, NF-κBp50, NF-κB-c-Rel, c-Fos, ATF-2and CREB-1 in Punarnavine treated B16 F-10 cells pointed to suppression of NF-κB signaling by Punarnavine.All these results demonstrate that Punarnavine induces apoptosis via activation of p53 induced caspase-3 mediatedpro-apoptotic signaling and suppression of NF-κB induced Bcl-2 mediated survival signaling.     

Multiple human chromosomes carrying tumor-suppressor functions for the mouse melanoma cell line B16-F10, identified by microcell-mediated chromosome transfer

Many tumor-suppressor genes are involved in the development and progression of cellular malignancy. To understand the functional role of tumor-suppressor genes in melanoma and to identify the human chromosome that carries these genes, we transferred individually each normal human chromosome, except for the Y chromosome, into the mouse melanoma cell line B16-F10, by microcell fusion. We examined the tumorigenicity of hybrid cells in nude mice and their in vitro growth properties. The introduction of human chromosomes 1 and 2 elicited a remarkable change in cell morphologic features, and cellular senescence was induced at seven to 10 population doublings. The growth rates of tumors derived from microcell hybrid clones containing introduced human chromosome 5, 7, 9, 10, 11, 13, 14, 15, 16, 19, 20, 21, 22, or X were significantly slower than that of the parental B16-F10 cells, whereas the introduction of other human chromosomes had no effect on the tumorigenicity of these cells. The majority of microcell hybrid clones that exhibited suppressed tumorigenicity also showed a moderate reduction in doubling time compared with B16-F10 cells. Microcell hybrid clones with an introduced human chromosome 5 showed complete suppression of in vitro-transformed phenotypes, including cell growth, saturation density, and colony-forming efficiency in soft agar. Thus, these results indicated the presence of many cell senescence-related genes and putative tumor-suppressor genes for the mouse melanoma cell line B16-F10 and showed in vitro that many tumor-suppressor genes control the phenotypes of transformed cells in the multistep process of neoplastic development.     

TAP expression reduces IL-10 expressing tumor infiltrating lymphocytes and restores immunosurveillance against melanoma

Many immune therapeutic strategies are under development for melanoma to treat metastatic disease and prevent disease reoccurrence. However, human melanoma cells are often deficient in antigen processing and this appears to play a role in their expansion and escape from immunosurveillance. For example, expression of the transporters associated with antigen processing (TAP1 and TAP2) is down-regulated in the mouse melanoma cell line B16F10. This results in a lack of tumor-associated antigen processing, low surface expression of MHC Class I molecules and low immunogenicity. We observe that restoration of TAP1 expression by transfection resurrects the processing and presentation of viral antigens, and the melanoma-associated antigen, TRP-2. Immunization with irradiated B16F10/rTAP1 transfected cells generates CTLs that are capable of killing B16F10/rTAP1 transfected targets and B16F10 targets deficient in TAP1. Furthermore, B16F10/rTAP1 transfectants grow at a significantly slower rate in mice than B16F10 cells. In an experimental model that closely recapitulates the clinical situation, treatment of B16F10 tumors in mice with a vaccinia virus vector expressing TAP1 also significantly decreases tumor growth in vivo. Furthermore, tumors treated with vaccinia TAP1 had significantly reduced numbers of immunosuppressive, CD3(+)/IL-10 positive, tumor infiltrating lymphocytes. Therefore, TAP1 expression restores both antigen presentation and immunogenicity in B16F10 melanoma cells and concomitantly reduces immunosuppressive IL-10 production at the local tumor site, thereby increasing immunosurveillance mechanisms against tumors.     

Noggin blocks invasive growth of murine B16-F1 melanoma cells in the optic cup of the chick embryo

Melanoma cells originate from the neural crest and are characterized by high migratory potential and invasive growth. After transplantation into the neural tube of the chick embryo, melanoma cells spontaneously emigrate along the neural crest pathways without tumor formation or malignant growth. This emigration depends on the constitutive over-expression of bone morphogenetic protein-2 (BMP-2) and can be ablated by the BMP-antagonist noggin. When transplanted into the embryonic optic cup, melanoma cells invade the host tissue and form malignant tumors. Here, we asked if the invasive growth of melanoma cells in the optic cup could be influenced by BMP-2 or noggin. Mouse B16-F1 cells were grown as aggregates, treated with BMP-2 or noggin during aggregation and transplanted into the optic cup of 3-day chick embryos. After 3 days of subsequent incubation, embryos were evaluated for melanoma cell invasiveness. Immunohistochemical examination revealed that untreated and BMP-2-treated melanoma cells had grown malignantly into the host tissue. However, noggin pretreatment of the aggregates had blocked melanoma cell invasiveness and tumor formation. We conclude that invasive growth of melanoma cells in vivo is BMP-dependent and can be ablated by noggin, thus rendering noggin a promising agent for the treatment of BMP-over-expressing melanoma.     

Altered characteristics of B16 melanoma cells induced by chemically crosslinking fibronectin to cell surfaces

The loss of fibronectin from tumor cell surfaces has been correlated with an increased incidence of metastases. To determine directly whether cell surface fibronectin influences the metastatic potential of solid tumors, we chemically crosslinked fibronectin to B16 murine melanoma cells using a photosensitive heterobifunctional crosslinking reagent, N-succinimidyl-4-azidophenyl-1,3 dithiopropionate (SADP). Cell attachment to plastic surfaces was increased in cells to which fibronectin was attached; cell growth over a 24-hr period was not significantly affected by the addition of fibronectin. When C57BL/6 mice were injected with fibronectin-crosslinked B16 cells, there was a 63% reduction in the number of pulmonary nodules compared to untreated controls. These results are consistent with the hypothesis that fibronectin enhances the recognition and removal of tumor cells from the circulation, possibly by cells of the reticuloendothelial system.     

Anti-angiogenic effects of the thienopyridine SR 25989 in vitro and in vivo in a murine pulmonary metastasis model

Neovascularisation is a key step in tumour growth and establishment of distant metastases. We have recently demonstrated that the thienopyridine SR 25989 an enantiomer of the anti-aggregant clopidogrel (Plavix) lacking anti-aggregant activity, inhibits endothelial cell proliferation in vitro by increasing the expression of endogenous thrombospondin-1, a natural potent inhibitor of angiogenesis. The anti-angiogenic effect of SR 25989 was further assessed in vitro in a quantitative assay of angiogenesis comprising a fragment of rat aorta embedded in a fibrin gel and in vivo in a pulmonary metastatic model using C57BL/6 mice inoculated in the foot pad with the highly metastatic melanoma cell line B16 F10. SR 25989 induced a dose dependent inhibition of spontaneous microvessel development in vitro reaching half maximal inhibition at around less than 50 microM and caused platelet derived growth factor induced angiogenesis to regress as a function of thienopyridine concentration. In vivo, SR 25989 did not alter significantly the growth rate of the primary tumour in the foot pad and did not inhibit development of inguinal nodes which appeared after amputation. However, the number and size of lung metastases were reduced in treated animals when examined at the time of sacrifice. In addition, the few metastases over 1 mm3 did not show any neovascularisation, as confirmed by negative von Willebrand immunostaining and in contrast to intense vascularisation seen in metastases developed by control mice. These results confirm that SR 25989 possesses potent anti-angiogenic properties and is able to inhibit metastatic dissemination and growth. The lack of effect on the primary tumour and inguinal nodes illustrates the complexity of the mechanisms involved in tumoural neo-angiogenesis and points out the possibility for distinct processes leading to neovascularisation in primary tumour as opposed to metastases.     

负载MnO2纳米颗粒的可得然复合水凝胶的构建及其联合光热疗法对黑色素瘤B16-F10细胞的杀伤效果

目的：构建负载二氧化锰（MnO2）纳米颗粒的可得然（Cur）复合水凝胶MnO2@Cur（简称MGel）,研究其对黑色素瘤B16-F10 细胞的杀伤效果。方法：采用热诱导法制备Cur 水凝胶（Gel）,物理负载MnO2构建MGel,表征其宏观和微观形貌,检测其机械性能、降解性能以及光热转换性能等理化性能,并研究其联合PTT 对小鼠皮肤黑色素瘤B16-F10 细胞的光热杀伤效果。结果：MGel 具有优异的机械和可降解性能,抗拉伸强度达（127.97±3.60）kPa、抗压缩强度达（151.44±5.23）kPa,28 d 降解率约58.17%。MGel 负载MnO2纳米片（粒径约 180 nm）获得优异的光热转换性能,负载1.0 mg/mL MnO2的MGel 在1.0 W/cm2的808 nm NIR光照4 min 后到达最高温度50 ℃。细胞毒性实验和Calcein-AM/PI 荧光双染色实验表明,MGel 联合PTT有效杀伤B16-F10 黑色素瘤细胞,NIR 光照使得MGel 组细胞存活率降低至（4.68±0.66）%（P<0.000 1）。结论：MGel 复合水凝胶具备优异的机械性能、可降解性能以及光热转换性能,其联合PTT能有效杀伤肿瘤细胞,可能成为一种有效治疗黑色素瘤的新手段。