Possibilities For Cancer Therapy Research Articles

Olive Leaves as a Source of Anticancer Compounds: In Vitro Evidence and Mechanisms.

Olive trees not only produce olives but also generate a substantial amount of waste and by-products, including leaves, pomace (the solid remains after pressing olives for oil), and wastewater from the olive oil-making process. The waste products, particularly the leaves, contain bioactive compounds, especially phenolic compounds, known for their health benefits, such as high antioxidant potential and the ability to reduce inflammation. These compounds have shown promise in preventing and treating cancer. This review, based on in vitro evidence, provides a detailed description and discussion of the mechanisms through which these compounds from olive leaves can prevent development, the ways they might act against cancer cells, and their potential to increase the sensitivity of tumor cells to conventional anticancer therapy. The possible synergistic effects of these compounds suggest that olive leaf extracts may offer a promising approach for cancer treatment, compared with isolated compounds, thus providing novel possibilities for cancer therapy.

The biological response of pH-switch-based gold nanoparticle-composite polyamino acid embolic material.

With continuous advances in medical technology, non-invasive embolization has emerged as a minimally invasive treatment, offering new possibilities in cancer therapy. Fluorescent labeling can achieve visualization of therapeutic agents in vivo, providing technical support for precise treatment. This paper introduces a novel in situ non-invasive embolization composite material, Au NPs@(mPEG-PLGTs), created through the electrostatic combination of L-cysteine-modified gold nanoparticles (Au NPs) and methoxy polyethylene glycol amine-poly[(L-glutamic acid)-(L-tyrosine)] (mPEG-PLGTs). Experiments were undertaken to confirm the biocompatibility, degradability, stability and performance of this tumor therapy. The research results demonstrated a reduction in tumor size as early as the fifth day after the initial injection, with a significant 90% shrinkage in tumor volume observed after a 20-day treatment cycle, successfully inhibiting tumor growth and exhibiting excellent anti-tumor effects. Utilizing near-infrared in vivo imaging, Au NPs@(mPEG-PLGTs) displayed effective fluorescence tracking within the bodies of nude BALB-c mice. This study provides a novel direction for the further development and innovation of in situ non-invasive embolization in the field, highlighting its potential for rapid, significant therapeutic effects with minimal invasiveness and enhanced safety.

A pH/ROS dual-responsive system for effective chemoimmunotherapy against melanoma via remodeling tumor immune microenvironment

Chemotherapeutics can induce immunogenic cell death (ICD) in tumor cells, offering new possibilities for cancer therapy. However, the efficiency of the immune response generated is insufficient due to the inhibitory nature of the tumor microenvironment (TME). Here, we developed a pH/reactive oxygen species (ROS) dual-response system to enhance chemoimmunotherapy for melanoma. The system productively accumulated in tumors by specific binding of phenylboronic acid (PBA) to sialic acids (SA). The nanoparticles (NPs) rapidly swelled and released quercetin (QUE) and doxorubicin (DOX) upon the stimulation of tumor microenvironment (TME). The in vitro and in vivo results consistently demonstrated that the NPs improved anti-tumor efficacy and prolonged survival of mice, significantly enhancing the effects of the combination. Our study revealed DOX was an ICD inducer, stimulating immune responses and promoting maturation of dendritic cells (DCs). Additionally, QUE served as a TME regulator by inhibiting the cyclooxygenase-2 (COX2)-prostaglandin E2 (PGE2) axis, which influenced various immune cells, including increasing cytotoxic T cells (CLTs) infiltration, promoting M1 macrophage polarization, and reducing regulatory T cells (Tregs) infiltration. The combination synergistically facilitated chemoimmunotherapy efficacy by remodeling the immunosuppressive microenvironment. This work presents a promising strategy to increase anti-tumor efficiency of chemotherapeutic agents.

Chlorambucil combined with a fluorophore for targeted cancer therapy and real-time monitoring of cancer cell death

The clinical applications of chlorambucil are limited by poor cellular permeability, lack of targeting, and severe side effects. In this study, a novel fluorophore-drug conjugate using chlorambucil as a model anticancer agent and 1,8-naphthalimide derivatives as the parent fluorophore was constructed. This novel fluorophore-drug conjugate could maintain a high concentration and high toxicity of drug in cancer cells by targeting lipid droplets. Cell imaging showed that the constructed novel fluorophore-drug conjugate exhibited a good cell uptake ability. Furthermore, the fluorophore component of conjugate acted as a fluorescent dye that emitted measurable signal when interacting with cancer cells. Therefore, fluorophore-drug conjugate showed the potential to be used for monitoring drug biodistribution in vivo in real time, which was of great significance in studying the mechanism of action of anticancer agents. Finally, we estimated of cancer cell death by monitoring the decrease in the number of lipid droplets and the increase in cell polarity. In conclusion, a novel fluorophore-drug conjugate with high cancer cell toxicity and capable of real-time monitoring of cancer cell survival status was successfully developed,opening up new possibilities for cancer therapy and diagnosis.

Small-size Ti3C2Tx MXene nanosheets coated with metal-polyphenol nanodots for enhanced cancer photothermal therapy and anti-inflammation.

As a controllable, simple method with few side effects, near-infrared (NIR) light-based photothermal therapy (PTT) has been proven an effective cancer therapeutic approach. However, PTT-induced inflammation is a potential negative factor. And the overexpressed heat shock proteins (HSPs) by cancer cells can protect them from hyperthermia during PTT. In this work, small-size Ti3C2Tx MXene nanosheets with high photothermal conversion efficiency in the region of NIR, high cargo loading capability and good free radical scavenging capability were chosen for cancer PTT and anti-inflammation. And (-)-epigallocatechin gallate (EGCG) was applied to form EGCG/Fe metal-polyphenol nanodots on the nanosheets. EGCG being released in acid cancer cells could reduce the expression of HSPs and could be used for anti-inflammation. As a result, the complex nanosheets named MXene@EGCG could achieve enhanced cancer PTT and be anti-inflammatory. Both in vitro and in vivo studies proved the good photothermal ability of MXene@EGCG and demonstrated that it could inhibit the expression of HSPs in tumor cells and relieve PTT-induced inflammation. Therefore, the nanosheets show good results in tumor ablation with a low level of inflammation, which provides another possibility for cancer therapy. STATEMENT OF SIGNIFICANCE: Photothermal therapy (PTT)-induced inflammation plays an essential role in some important stages of tumor development and is unfavorable for cancer treatment. And hyperthermia leads to the overexpression of heat shock proteins (HSPs) in cancer cells, which limits the therapeutic effect of PTT. Therefore, we coated small-size Ti3C2Tx MXene nanosheets with (-)-epigallocatechin gallate (EGCG)/Fe metal-polyphenol nanodots and named them as MXene@EGCG. This system shows a good photothermal conversion efficiency at 808 nm. And it can release EGCG in cancer cells to inhibit the expression of HSPs, thus achieving an enhanced cancer PTT. Both MXene and EGCG can also diminish the PTT-trigged inflammation. Both in vitro and in vivo studies prove the good anti-cancer PTT effect and anti-inflammation capability of MXene@EGCG.

Anticancer Potential of Natural Bark Products-A Review.

Cell biology, plant-based extracts, structural chemistry, and laboratory in vitro or in vivo experiments are the principal aspects or interfaces that can contribute to discovering new possibilities in cancer therapy and to developing improved chemotherapeutics. Forestry residues can be used for their wealthy resource in polyphenols and other phytoconstituents known for anticancer properties. This review is designed to bring together information on the in vitro or in vivo anticancer potential of woody vascular plants especially the bark extracts (BE) and biosynthesized metallic nanoparticles (BMN) using bark extracts. Type of extracts, main phytoconstituents found in extracts responsible for the anticancer activity, and targeted cancerous cell lines were followed. The literature data were collected via Clarivate Analytics, Science Direct, PubMed, and Google Academic (2011–2021). The search terms were: bark extracts, metallic nanoparticles, silver nanoparticles, gold nanoparticles, anticancer, cytotoxic activity, antiproliferative effect, and antimetastatic potential in vitro and in vivo. All of the search terms listed above were used in different combinations. The literature data highlight the efficaciousness of the BE and BMN as anticancer agents in in vitro experiments and showed the mechanism of action and their advantage of nontoxicity on normal cells. In vitro testing has shown promising results of the BE and BMN effect on different cancer cell lines. In vivo testing is lacking and more data is necessary for drug development on animal models.

The Mechanism of Warburg Effect-Induced Chemoresistance in Cancer.

Although chemotherapy can improve the overall survival and prognosis of cancer patients, chemoresistance remains an obstacle due to the diversity, heterogeneity, and adaptability to environmental alters in clinic. To determine more possibilities for cancer therapy, recent studies have begun to explore changes in the metabolism, especially glycolysis. The Warburg effect is a hallmark of cancer that refers to the preference of cancer cells to metabolize glucose anaerobically rather than aerobically, even under normoxia, which contributes to chemoresistance. However, the association between glycolysis and chemoresistance and molecular mechanisms of glycolysis-induced chemoresistance remains unclear. This review describes the mechanism of glycolysis-induced chemoresistance from the aspects of glycolysis process, signaling pathways, tumor microenvironment, and their interactions. The understanding of how glycolysis induces chemoresistance may provide new molecular targets and concepts for cancer therapy.

DNA-PKcs: A Multi-Faceted Player in DNA Damage Response.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a member of the phosphatidylinositol 3-kinase related kinase family, which can phosphorylate more than 700 substrates. As the core enzyme, DNA-PKcs forms the active DNA-PK holoenzyme with the Ku80/Ku70 heterodimer to play crucial roles in cellular DNA damage response (DDR). Once DNA double strand breaks (DSBs) occur in the cells, DNA-PKcs is promptly recruited into damage sites and activated. DNA-PKcs is auto-phosphorylated and phosphorylated by Ataxia-Telangiectasia Mutated at multiple sites, and phosphorylates other targets, participating in a series of DDR and repair processes, which determine the cells’ fates: DSBs NHEJ repair and pathway choice, replication stress response, cell cycle checkpoints, telomeres length maintenance, senescence, autophagy, etc. Due to the special and multi-faceted roles of DNA-PKcs in the cellular responses to DNA damage, it is important to precisely regulate the formation and dynamic of its functional complex and activities for guarding genomic stability. On the other hand, targeting DNA-PKcs has been considered as a promising strategy of exploring novel radiosensitizers and killing agents of cancer cells. Combining DNA-PKcs inhibitors with radiotherapy can effectively enhance the efficacy of radiotherapy, offering more possibilities for cancer therapy.

SOLTI-1503 PROMETEO TRIAL: combination of talimogene laherparepvec with atezolizumab in early breast cancer.

New treatment strategies such as immune checkpoint inhibitors and oncolytic viruses are opening new possibilities in cancer therapy. Preliminary results in melanoma and other tumors showed that the combination of talimogene laherparepvec with an anti-PD-1/PD-L1 or anti-CTLA4 has greater efficacy than either therapy alone, without additional safety concerns beyond those expected for each agent. The presence of residual cancer after neoadjuvant chemotherapy in early breast cancer patients is an unmet medical need. SOLTI-1503 PROMETEO is a window of opportunity trial, which evaluates the combination of talimogene laherparepvec in combination with atezolizumab in women with operable HER2-negative breast cancer who present residual disease after neoadjuvant chemotherapy. The primary end point is the rate of residual cancer burden 0/1. Clinical Trial Registration: NCT03802604.

Abstract OT1-01-01: SOLTI-1503 PROMETEO: Combination of talimogene laherparepvec (T-VEC) with atezolizumab in patients with residual breast cancer after standard neoadjuvant multi-agent chemotherapy

Abstract Background: New strategies as immune blockade inhibitors and oncolytic viruses are opening new possibilities in cancer therapy. Preliminary results in melanoma showed that the combination of Talimogene Laherparevec (T-VEC) with an anti PD-L1 or anti CTLA4 has greater efficacy than either therapy alone, without additional safety concerns beyond those expected for each individual agent. The presence of residual cancer after neoadjuvant chemotherapy (NAC) in early breast cancer (BC) patients is an unmet medical need. We hypothesize that combining T-VEC with Atezolizumab may offer clinical benefit in the preoperative setting for early BC patients with intermediate to high risk of recurrence who present residual disease (RD) after standard NAC. Methods: PROMETEO is an open-label, multicenter trial of T-VEC in combination with Atezolizumab in patients with residual disease after completing standard NAC. 30 patients with triple negative breast cancer (TNBC) or Luminal B-like/Her2- (ER/PR>10% and Ki-67 ≥30% or ER/PR 1-10% and Ki-67 ≥20%) will be included. RD must be confirmed by core-biopsy and have a diameter ≥ 15mm measured by magnetic resonance imaging. Adequate organ function and ECOG PS 0-1 are required. T-VEC is administered intratumorally in week 1 (106 plaque-forming units/mL [pfu/mL]), then in week 4 and every 2 weeks thereafter (108 pfu/mL) for four injections. Atezolizumab (840 mg) is administered intravenously every 2 weeks for four infusions, beginning in week 4. BC surgery will be carried out 1 to 3 weeks after completion of study treatment. Primary objective is to evaluate the effect of T-VEC + Atezolizumab by comparing the expression of a gene signature tracking activated CD8 T-cells between RD at surgery and RD after NAC. We expect a relative increase of ≥20% in the expression of this CD8 T-cell gene signature in 20% of patients or more, defined as the mean expression of PRF1, CD8A, GZMM, CD8B and FLT3LG, between post and pre-treatment samples. Secondary endpoints include pathologic complete response rate and residual cancer burden, objective response rate, and safety. Two safety data reviews - after 4 and 10 patients complete treatment - are planned. A total of 4 sites in Spain are participating in the trial. To date, 4 patients have been included and it is expected to complete the first safety data review in September 2019. The study recruitment is planned to be completed by October 2020. Clinical trial identification: NCT03802604 Citation Format: Tomás Pascual, Patricia Villagrasa, María J Vidal, Sergi Ganau, Begoña Bermejo, Ana Julve, Esther Zamora, Ignacio Miranda, Estela Vega, Cristina Marquez, Mafalda Oliveira, Juan Miguel Cejalvo, Luis de la Cruz, Manel Juan, Jordi Canes, Xavier Gonzalez, Aleix Prat. SOLTI-1503 PROMETEO: Combination of talimogene laherparepvec (T-VEC) with atezolizumab in patients with residual breast cancer after standard neoadjuvant multi-agent chemotherapy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-01-01.

Synthesis and biological evaluation of novel millepachine derivative containing aminophosphonate ester species as novel anti-tubulin agents.

A new series of millepachine derivative containing aminophosphonate ester moieties were designed and synthesized, and evaluated for their anticancer activities using MTT assay. Among all the compounds, compound 9m exhibited the most potent cytotoxic activity against all tested human cancer cell lines including multidrug resistant phenotype, which inhibited cancer cell growth with IC50 values ranging from 0.85 to 3.09μM, respectively. In addition, its low cytotoxicity toward human normal liver cells HL-7702 and sensitivity toward to doxorubicin or cisplatin-resistant cells indicated the possibility for cancer therapy. Furthermore, 9m significantly induced cell apoptosis and cell cycle arrest in G2/M phase and dramatically disrupted the microtubule organization. Moreover, a decrease in MMP, an increase in reactive oxygen species (ROS) generation and Bax/Bcl-2 ratio, accompanied by activated caspase-3 and -9, were observed in HepG-2 cells after incubation with 9m, indicating that the mitochondrial pathway was involved in the 9m-mediated apoptosis.

Formulation and in vitro evaluation of magnetoliposomes as a potential nanotool in colorectal cancer therapy.

Magnetoliposomes (MLPs) offer many new possibilities in cancer therapy and diagnosis, including the transport of antitumor drugs, hyperthermia treatment, detection using imaging techniques, and even cell migration. However, high biocompatibility and functionality after cell internalization are essential to their successful application. We synthesized maghemite nanoparticles (γ-Fe2O3) by oxidizing magnetite cores (Fe3O4) and coating them with phosphatidylcholine (PC) liposomes, obtained using the thin film hydration method, to generate MLPs. The MLPs were tested in vitro, using human tumor and non-tumor colon cell lines, for cytotoxicity, cell uptake and cellular distribution, and magnetically-induced cell mobility. In addition, blood cells biocompatibility studies were performed. The mean size of the MLPs, with a core of γ-Fe2O3 completely surrounded by PC liposomes, was 90 ± 20 nm, showing a soft magnetic character and a great biocompatibility in all the cell lines assayed including blood cells. Prussian blue staining showed a high MLP cell uptake with maximum internalization at 24 h. TEM analysis showed the MLPs surrounded by the cell membrane and in the cell periphery, suggesting internalization by endocytosis and/or macropinocytosis. Interestingly, the mitochondria presented MLP accumulations, particularly in tumor cells. Finally, MLPs within colon cancer cells were able to induce cell migration when a magnetic field was applied in vitro, indicating the functionality of our nanoformulation. A promising biomedical application of these MLPs is anticipated based on their physical, chemical and biological properties.

Genomic Signature of the Natural Oncolytic Herpes Simplex Virus HF10 and Its Therapeutic Role in Preclinical and Clinical Trials.

Oncolytic viruses (OVs) are opening new possibilities in cancer therapy with their unique mechanism of selective replication within tumor cells and triggering of antitumor immune responses. HF10 is an oncolytic herpes simplex virus-1 with a unique genomic structure that has non-engineered deletions and insertions accompanied by frame-shift mutations, in contrast to the majority of engineered OVs. At the genetic level, HF10 naturally lacks the expression of UL43, UL49.5, UL55, UL56, and latency-associated transcripts, and overexpresses UL53 and UL54. In preclinical studies, HF10 replicated efficiently within tumor cells with extensive cytolytic effects and induced increased numbers of activated CD4+ and CD8+ T cells and natural killer cells within the tumor, leading to a significant reduction in tumor growth and prolonged survival rates. Investigator-initiated clinical studies of HF10 have been completed in recurrent breast carcinoma, head and neck cancer, and unresectable pancreatic cancer in Japan. Phase I trials were subsequently completed in refractory superficial cancers and melanoma in the United States. HF10 has been demonstrated to have a high safety margin with low frequency of adverse effects in all treated patients. Interestingly, HF10 antigens were detected in pancreatic carcinoma over 300 days after treatment with infiltration of CD4+ and CD8+ T cells, which enhanced the immune response. To date, preliminary results from a Phase II trial have indicated that HF10 in combination with ipilimumab (anti-CTLA-4) is safe and well tolerated, with high antitumor efficacy. Improvement of the effect of ipilimumab was observed in patients with stage IIIb, IIIc, or IV unresectable or metastatic melanoma. This review provides a concise description of the genomic functional organization of HF10 compared with talimogene laherparepvec. Furthermore, this review focuses on HF10 in cancer treatment as monotherapy as well as in combination therapy through a concise description of all preclinical and clinical data. In addition, we will address approaches for future directions in HF10 studies as cancer therapy.

MicroRNAs and Chinese Medicinal Herbs: New Possibilities in Cancer Therapy.

In recent decades Chinese medicine has been used worldwide as a complementary and alternative medicine to treat cancer. Plenty of studies have shown that microRNAs (miRNAs) play fundamental roles in many pathological processes, including cancer, while the anti-cancer mechanisms of Chinese medicinal herbs targeting miRNAs also have been extensively explored. Our previous studies and those of others on Chinese medicinal herbs and miRNAs in various cancer models have provided a possibility of new cancer therapies, for example, up-regulating the expression of miR-23a may activate the positive regulatory network of p53 and miR-23a involved in the mechanism underlying the anti-tumor effect of berberine in hepatocellular carcinoma (HCC). In this review, we survey the role of Chinese medicinal herbal products in regulating miRNAs in cancer and the use of mediating miRNAs for cancer treatment. In addition, the controversial roles of herb-derived exogenous miRNAs in cancer treatment are also discussed. It is expected that targeting miRNAs would provide a novel therapeutic approach in cancer therapy by improving overall response and survival outcomes in cancer treatment, especially when combined with conventional therapeutics and Chinese medicinal herbal products.

Modulating the structure of EGFR with UV light: new possibilities in cancer therapy.

The epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases. EGFR is activated upon binding to e.g. epidermal growth factor (EGF), leading to cell survival, proliferation and migration. EGFR overactivation is associated with tumor progression. We have previously shown that low dose UVB illumination of cancer cells overexpressing EGFR prior to adding EGF halted the EGFR signaling pathway. We here show that UVB illumination of the extracellular domain of EGFR (sEGFR) induces protein conformational changes, disulphide bridge breakage and formation of tryptophan and tyrosine photoproducts such as dityrosine, N-formylkynurenine and kynurenine. Fluorescence spectroscopy, circular dichroism and thermal studies confirm the occurrence of conformational changes. An immunoassay has confirmed that UVB light induces structural changes in the EGF binding site. A monoclonal antibody which competes with EGF for binding sEGFR was used. We report clear evidence that UVB light induces structural changes in EGFR that impairs the correct binding of an EGFR specific antibody that competes with EGF for binding EGFR, confirming that the 3D structure of the EGFR binding domain suffered conformational changes upon UV illumination. The irradiance used is in the same order of magnitude as the integrated intensity in the solar UVB range. The new photonic technology disables a key receptor and is most likely applicable to the treatment of various types of cancer, alone or in combination with other therapies.

Knock-down of ubiquitin-specific protease 22 by micro-RNA interference inhibits colorectal cancer growth

Increasing experimental evidences suggest that ubiquitin-specific protease 22 (USP22), a cancer stem cell marker, plays a crucial role in pathological processes of epithelial malignancies and other solid tumors, which makes it a potential target for cancer therapy. The aim of this study was to study the roles of USP22 in human colorectal cancer cell line HCT116 by suppressing USP22 expression with micro-interfering RNA (miRNA). With the knock-down of USP22, the changes of cellular proliferation, cell cycle, cell apoptosis, and major vault protein (MVP) expression were investigated. Furthermore, a tumor xenograft model in nude mice was injected with USP22 miRNA silencing vector and the immunohistochemical staining was performed to evaluate the USP22 expression in the tumor. The knock-down of USP22 protein expression by miRNA resulted in the inhibition of cellular proliferation, the accumulation of cells in the G1 phase, the reduction of apoptosis, and the down-regulation of MVP expression. Furthermore, with orthotopic mice as a model, tumor growth was suppressed when USP22 miRNA silencing vector was injected. Immunohistochemical analyses of tumor sections revealed that USP22 expression in animals decreased when USP22 expression was inhibited by miRNA. These results support the hypothesis that USP22 plays a crucial role in tumor formation and growth by regulating cell proliferation with USP22-dependent signaling pathway. Furthermore, USP22 acts as a major transcriptional factor to regulate MVP drug resistant gene. Taken together, targeting USP22 may offer additional possibilities in cancer therapy.

Implicación del colesterol de membrana en la proliferación, ciclo y diferenciación de las células leucémicas humanas HL-60

Introduction Cholesterol metabolism is increased in leukaemia cells and, accordingly, the use of chemotherapeutic agents in combination with statins for cancer treatment is being evaluated. In our laboratory, we demonstrated that cholesterol deficiency, as produced by distal inhibitors of the cholesterol biosynthesis pathway, induces the differentiation of HL-60 human leukaemia cells through the granulocytic pathway. The aim of the present work was to determine whether the selective extraction of cholesterol from the cell membrane induces cell differentiation, which may open new possibilities in cancer therapy and other proliferative processes. Material and methods Promyelocytic HL-60 cells were maintained in a cholesterol-free medium. Cholesterol was extracted by incubating the cells in the presence of methyl-β-cyclodextrin. Cholesterol cell content was measured by HPLC; cell proliferation was assessed by cell counting; cell cycle distribution was analysed by flow cytometry. Cell differentiation was assessed by measuring CD11c expression by flow cytometry and NADPH oxidase components by Western blot. Results Treatment with methyl-β-cyclodextrin reduced the cholesterol content in cells, and resulted in cell proliferation inhibition, the induction of CD11c expression and the synthesis of p47 phox and p67 phox. Conclusions Selective extraction of membrane cholesterol in HL-60 cells triggers cell differentiation, as indicated by the expression of both CD11c and NADPH oxidase components. Results Treatment with methyl-β-cyclodextrin reduced the cell cholesterol content and inhibited cell proliferation in a dose-dependent manner. As this treatment is prolonged, part of the cells die but a substantial proportion of cells survives and acquire differentiation markers, such as CD11c, p47 phox and p67 phox. Conclusions Selective extraction of membrane cholesterol in HL-60 cells induces cell cycle arrest, which is followed by cell death and, alternatively, cell differentiation, as indicated by the expression of both CD11c and NADPH oxidase components.

Lysosomal cell death pathways: new possibilities for cancer therapy

Lysosomal cell death pathways: new possibilities for cancer therapy

SAFROLE OXIDE INDUCES APOPTOSIS IN A549 HUMAN LUNG CANCER CELLS

3,4-(Methylenedioxy)-1-(2′,3′-epoxypropyl)-benzene (safrole oxide) was synthesized in the authors' laboratory. To investigate the effects of safrole oxide on the growth and apoptosis of A549 human lung cancer cells, the authors treated the cells with safrole oxide, 112.36 to 449.44 μmol/L, for 24 to 48 hours. The results showed that the drug led A549 cells to apoptosis and blocked cell cycle completely at G1 phase and partly at G2-M phase. To further study the correlated mechanism, the authors examined P53 and H-Ras protein expressions by using immunofluorescence assay. They found that the expression of P53 was dramatically up-regulated but the expression of H-Ras was hardly affected by safrole oxide, 224.72 μmol/L, within 24 hours. Taken together, these results revealed that safrole oxide could induce apoptosis of A549 cells and suggested that safrole oxide might perform its function by blocking cells completely at G1 phase and partly at G2-M phase, and also by up-regulating the expression of P53 protein. These findings would raise exciting possibilities for cancer therapy in future.

Impaired surface antigen presentation in tumors: implications for T cell-based immunotherapy

The identification of tumor-associated antigens has suggested new possibilities for cancer therapy. However, multiple mechanisms may contribute to the ability of tumor to escape antitumor immune responses. Tumor antigen heterogeneity, modulation of HLA expression and immune suppressive mechanisms may occur at any time during tumor cell progression, and can affect the outcome of therapeutic immune intervention. In particular, the appearence of altered HLA class I phenotypes during tumor development may have important biological and medical implications due to the role of these molecules in T and NK cell functions. Exhaustive tumor tissue studies are necessary before deciding whether a particular patient is suitable for inclusion in T cell-based immunotherapy protocols.