Preparation, characterization, pharmacokinetics and anticancer effects of PEGylated β-elemene liposomes

Objective:This study aimed to develop a new polyethylene glycol(PEG)ylatedβ-elemene liposome(PEG-Lipo-β-E)and evaluate its characterization,pharmacokinetics,antitumor effects and safety in vitro and in vivo.Methods:The liposomes were prepared by ethanol injection and high-pressure micro-jet homogenization.Characterization of the liposomes was conducted,and drug content,entrapment efficiency(EE),in vitro release and stability were studied by ultra-fast liquid chromatography(UFLC)and a liquid surface method.Blood was drawn from rats to establish the pharmacokinetic parameters.The anticancer effect was evaluated in a KU-19-19 bladder cancer xenograft model.Histological analyses were performed to evaluate safety.Results:The PEG-Lipo-β-E showed good stability and was characterized as 83.31±0.181 nm in size,0.279±0.004 in polydispersity index(PDI),-21.4±1.06 mV in zeta potential,6.65±0.02 in pH,5.024±0.107 mg/mL inβ-elemene(β-E)content,and 95.53±1.712%in average EE.The Fourier transform infrared spectroscopy(FTIR)and differential scanning calorimetry(DSC)indicated the formation of PEG-Lipo-β-E.Compared to elemene injection,PEG-Lipo-β-E demonstrated a 1.75-fold decrease in clearance,a 1.62-fold increase in half-life,and a 1.76-fold increase in area under the concentration-time curves(AUCs)from 0 hour to 1.5 hours(P<0.05).PEG-Lipo-β-E also showed an enhanced anticancer effect in vivo.Histological analyses showed that there was no evidence of toxicity to the heart,kidney,liver,lung or spleen.Conclusions:The present study demonstrates PEG-Lipo-β-E as a new formulation with ease of preparation,high EE,good stability,improved bioavailability and antitumor effects.

An ATF24 peptide-functionalized β-elemene-nanostructured lipid carrier combined with cisplatin for bladder cancer treatment

Objective:In this study,we aimed to develop an amino-terminal fragment(ATF)peptide-targeted liposome carryingβ-elemene(ATF24-PEG-Lipo-β-E)for targeted delivery into urokinase plasminogen activator receptor-overexpressing bladder cancer cells combined with cisplatin(DDP)for bladder cancer treatment.Methods:The liposomes were prepared by ethanol injection and high-pressure microjet homogenization.The liposomes were characterized,and the drug content,entrapment efficiency,andin vitro release were studied.The targeting efficiency was investigated using confocal microscopy,ultra-fast liquid chromatography,and an orthotopic bladder cancer model.The effects of ATF24-PEG-Lipo-β-E combined with DDP on cell viability and proliferation were evaluated by a Cell Counting Kit-8(CCK-8)assay,a colony formation assay,and cell apoptosis and cell cycle analyses.The anticancer effects were evaluated in a KU-19-19 bladder cancer xenograft model.Results:ATF24-PEG-Lipo-β-E had small and uniform sizes(~79 nm),high drug loading capacity(~5.24 mg/mL),high entrapment efficiency(98.37±0.95%),and exhibited sustained drug release behavior.ATF24-PEG-Lipo-β-E had better targeting efficiency and higher cytotoxicity than polyethylene glycol(PEG)ylatedβ-elemene liposomes(PEG-Lipo-β-E).DDP,combined with ATF24-PEG-Lipo-β-E,exerted a synergistic effect on cellular apoptosis and cell arrest at the G2/M phase,and these effects were dependent on the caspase-dependent pathway and Cdc25C/Cdc2/cyclin B1 pathways.Furthermore,thein vivo antitumor activity showed that the targeted liposomes effectively inhibited the growth of tumors,using the combined strategy.Conclusions:The present study provided an effective strategy for the targeted delivery ofβ-elemene(β-E)to bladder cancer,and a combined strategy for bladder cancer treatment.

温和光热疗法在肿瘤治疗中的研究进展

癌症是目前世界上发病率和死亡率最高的疾病之一.光热疗法(photothermal therapy,PTT)是一种无创的癌症治疗新策略,即把具有较高光热转化效率的材料(photothermal agent,PTA)注入人体内部,利用靶向性聚集在肿瘤组织附近,再在近红外(near-infrared,NIR)等外部光源的照射下,将光能转化为热能来杀死癌细胞.然而,光热治疗所需要达到的高温可能对正常组织损伤较大,因此,相对低温的温和光热疗法(mild photothermal therapy,MPTT)备受关注.温和光热疗法本身的抗肿瘤作用有限,通常需与其他疗法联合以构建协同治疗体系,达到治疗肿瘤的目的.近期,本团队合成了一种二维锗量子点光热转换材料,突破了既往无法得到二维材料以及传统材料光热转换效率低的重大难题.本文从温和光热疗法常用光热转换剂的类型及特点、主要障碍及其解决策略、抗肿瘤作用机制、与其他疗法联合的效果等方面对温和光热疗法在肿瘤治疗中的研究现状进行系统性总结,并对未来的发展方向进行展望和讨论,旨在为肿瘤治疗提供一种新思路和新方法.

中西医结合防治肿瘤耐药的研究进展

化疗和靶向治疗是晚期恶性肿瘤的主要治疗方法之一,而其耐药性是导致肿瘤治疗失败的重要原因.引起肿瘤耐药的原因有肿瘤细胞的异质性、药物外排及代谢失活、肿瘤微环境变化、DNA损伤修复失调、表观遗传改变等多种因素.当前,临床上主要采取更换联合化疗用药或更换新的抗肿瘤药物的策略来克服肿瘤耐药,但由于该方法作用靶点单一,且治疗耐药过程中容易产生新的耐药甚至多药耐药,导致肿瘤治疗的难度增大.因此,寻找高效、低毒、广谱的逆转肿瘤耐药方法或药物已成为当今肿瘤领域的研究热点及难点.中医药由于成分复杂,可以通过多组分、多靶点呈现多方面抗肿瘤作用,因而在增强抗肿瘤药物敏感性或克服肿瘤耐药方面具有巨大潜能.本文系统阐述了肿瘤耐药的发生机制,分析了现代医学和传统中医学在克服肿瘤耐药方面的最新研究进展,旨在为增强抗肿瘤药物的敏感性或克服肿瘤耐药提供一种新的思路和策略.

Baicalin induces ferroptosis in bladder cancer cells by downregulating FTH1

Ferroptosis is a non-apoptotic regulated cell death caused by iron accumulation and subsequent lipid peroxidation.Currently,the therapeutic role of ferroptosis on cancer is gaining increasing interest.Baicalin an active component in Scutellaria baicalensis Georgi with anticancer potential various cancer types;however,the effects of baicalein on bladder cancer and the underlying molecular mechanisms remain largely unknown.In the study,we investigated the effect of baicalin on bladder cancer cells5637 and KU-19-19.As a result,we show baicalin exerted its anticancer activity by inducing apoptosis and cell death in bladder cancer cells.Subsequently,we for the first time demonstrate baicalin-induced ferroptotic cell death in vitro and in vivo,accompanied by reactive oxygen species(ROS) accumulation and intracellular chelate iron enrichment.The ferroptosis inhibitor deferoxamine but not necrostatin-1,chloroquine(CQ),N-acetyl-L-cysteine,L-glutathione reduced,or carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone(Z-VAD-FMK) rescued baicalin-induced cell death,indicating ferroptosis contributed to baicalin-induced cell death.Mechanistically,we show that ferritin heavy chain1(FTH1) was a key determinant for baicalin-induced ferroptosis.Overexpression of FTH1 abrogated the anticancer effects of baicalin in both 5637 and KU19-19 cells.Taken together,our data for the first time suggest that the natural product baicalin exerts its anticancer activity by inducing FTH1-dependent ferroptosis,which will hopefully provide a prospective compound for bladder cancer treatment.

Erianin,a novel dibenzyl compound in Dendrobium extract,inhibits lung cancer cell growth and migration via calcium/calmodulin-dependent ferroptosis

Ferroptosis,a novel form of programmed cell death,is characterized by iron-dependent lipid peroxidation and has been shown to be involved in multiple diseases,including cancer.Stimulating ferroptosis in cancer cells may be a potential strategy for cancer therapy.Therefore,ferroptosis-inducing drugs are attracting more attention for cancer treatment.Here,we showed that erianin,a natural product isolated from Dendrobium chrysotoxum Lindl,exerted its anticancer activity by inducing cell death and inhibiting cell migration in lung cancer cells.Subsequently,we demonstrated for the first time that erianin induced ferroptotic cell death in lung cancer cells,which was accompanied by ROS accumulation,lipid peroxidation,and GSH depletion.The ferroptosis inhibitors Fer-1 and Lip-1 but not Z-VAD-FMK,CQ,or necrostatin-1 rescued erianin-induced cell death,indicating that ferroptosis contributed to erianin-induced cell death.Furthermore,we demonstrated that Ca^(2+)/CaM signaling was a critical mediator of erianin-induced ferroptosis and that blockade of this signaling significantly rescued cell death induced by erianin treatment by suppressing ferroptosis.Taken together,our data suggest that the natural product erianin exerts its anticancer effects by inducing Ca^(2+)/CaMdependent ferroptosis and inhibiting cell migration,and erianin will hopefully serve as a prospective compound for lung cancer treatment.

PCDH17 increases the sensitivity of colorectal cancer to 5-fluorouracil treatment by inducing apoptosis and autophagic cell death

5-Fluorouracil(5-FU)is known as a first-line chemotherapeutic agent against colorectal cancer(CRC),but drug resistance occurs frequently and significantly limits its clinical success.Our previous study showed that the protocadherin 17(PCDH17)gene was frequently methylated and functioned as a tumor suppressor in CRC.However,the relationship between PCDH17 and 5-FU resistance in CRC remains unclear.Here,we revealed that PCDH17 was more highly expressed in 5-FU-sensitive CRC tissues than in 5-FU-resistant CRC tissues,and high expression of PCDH17 was correlated with high BECN1 expression.Moreover,this expression profile contributed to superior prognosis and increased survival in CRC patients.Restoring PCDH17 expression augmented the 5-FU sensitivity of CRC in vitro and in vivo by promoting apoptosis and autophagic cell death.Furthermore,autophagy played a dominant role in PCDH17-induced cell death,as an autophagy inhibitor blocked cell death to a greater extent than the pancaspase inhibitor Z-VAD-FMK.PCDH17 inhibition by siRNA decreased the autophagy response and 5-FU sensitivity.Mechanistically,we showed that c-Jun NH2-terminal kinase(JNK)activation was a key determinant in PCDH17-induced autophagy.The compound SP600125,an inhibitor of JNK,suppressed autophagy and 5-FU-induced cell death in PCDH17-reexpressing CRC cells.Taken together,our findings suggest for the first time that PCDH17 increases the sensitivity of CRC to 5-FU treatment by inducing apoptosis and JNK-dependent autophagic cell death.PCDH17 may be a potential prognostic marker for predicting 5-FU sensitivity in CRC patients.

The inflammatory microenvironment and the urinary microbiome in the initiation and progression of bladder cancer

Accumulating evidence suggests that chronic inflammation may play a critical role in various malignancies,including bladder cancer.This hypothesis stems in part from inflammatory cells observed in the urethral microenvironment.Chronic inflammation may drive neoplastic transformation and the progression of bladder cancer by activating a series of in-flammatory molecules and signals.Recently,it has been shown that the microbiome also plays an important role in the development and progression of bladder cancer,which can be mediated through the stimulation of chronic inflammation.In effect,the urinary microbiome can play a role in establishing the inflammatory urethral microenvironment that may facilitate the development and progression of bladder cancer.In other words,chronic inflammation caused by the urinary microbiome may promote the initiation and progression of bladder cancer.Here,we provide a detailed and comprehensive account of the link between chronic inflammation,the microbiome and bladder cancer.Finally,we highlight that targeting the urinary microbiome might enable the development of strategies for bladder cancer prevention and personalized treatment.