Evasion of apoptosis as a cellular stress response in cancer. Int J Cell Biol. 2010;2010:370835. [PMID: 20182539 PMCID: PMC2825553 DOI: 10.1155/2010/370835]

Harnessing the potential of hydrogels for advanced therapeutic applications: current achievements and future directions

The applications of hydrogels have expanded significantly due to their versatile, highly tunable properties and breakthroughs in biomaterial technologies. In this review, we cover the major achievements and the potential of hydrogels in therapeutic applications, focusing primarily on two areas: emerging cell-based therapies and promising non-cell therapeutic modalities. Within the context of cell therapy, we discuss the capacity of hydrogels to overcome the existing translational challenges faced by mainstream cell therapy paradigms, provide a detailed discussion on the advantages and principal design considerations of hydrogels for boosting the efficacy of cell therapy, as well as list specific examples of their applications in different disease scenarios. We then explore the potential of hydrogels in drug delivery, physical intervention therapies, and other non-cell therapeutic areas (e.g., bioadhesives, artificial tissues, and biosensors), emphasizing their utility beyond mere delivery vehicles. Additionally, we complement our discussion on the latest progress and challenges in the clinical application of hydrogels and outline future research directions, particularly in terms of integration with advanced biomanufacturing technologies. This review aims to present a comprehensive view and critical insights into the design and selection of hydrogels for both cell therapy and non-cell therapies, tailored to meet the therapeutic requirements of diverse diseases and situations.

Necroptosis induced by ruthenium (II) complexes as mitochondrial disruptors

Inducing necroptosis in cancer cells has emerged as an effective strategy to overcome drug resistance. However, while organic small molecules have been extensively studied for this purpose, metal-based compounds have received relatively little attention as triggers of necroptosis. The development of ruthenium (II) hybrid compounds, particularly those containing triazene (Ru-TRZ), highlights a novel avenue for modulating necroptotic cell death. Here we show that incorporating a methyltriazene moiety, a known alkylating warhead, confers superior mitochondrial-targeting properties and enhances cell death compared to amide-containing counterparts. Ru-hybrid TRZ2 exhibits also antitumor efficacy against in vivo drug-resistant cancer cells. Mechanistically, we demonstrate that Ru-TRZ hybrids induce apoptosis. In addition, by activating downstream RIPK3-driven cell death, TRZ2 proficiently restrains normal mitochondrial function and activity, leading to cancer cell necroptosis. Finally, TRZ2 synergizes anti-proliferative activity and cell death effects induced by conventional drugs. In conclusion, Ru-TRZ2 stands as a promising ruthenium-based chemotherapeutic agent inducing necroptosis in drug resistant cancer cells.

Induction of heat shock protein expression in SP2/0 transgenic cells and its effect on the production of monoclonal antibodies

The objective of the current investigation was to evaluate the induction of heat shock proteins (HSPs) in SP2/0 transgenic cells and the effect of these proteins on the production of monoclonal antibodies (mAbs). The SP2/0 cell line expressing the PSG-026 antibody, a biosimilar candidate of golimumab, the culture parameters, and the target protein expression were not justified for industrial production and were used for the experiments. Paracetamol and heat shock were used as chemical and physical inducers of HSPs, respectively. The results showed that paracetamol and heat shock increased the expression of HSP70 and HSP27 at the mRNA and protein levels. The expression of HSPs was greater in paracetamol-treated cells than in heat shock-treated cells. Paracetamol treatment at concentrations above 0.5 mM significantly reduced cell viability and mAb expression. However, treatment with 0.25 mM paracetamol results in delayed cell death and increased mAb production. Heat shock treatment at 45°C for 30 minutes after enhanced mAb expression was applied after pre-treatment with paracetamol. In bioreactor cultures, pretreatment of cells with paracetamol improved cell viability and shortened the lag phase, resulting in increased cell density. The production of mAbs in paracetamol-treated cultures was markedly greater than that in the control. Analysis of protein quality and charge variants revealed no significant differences between paracetamol-treated and control cultures, indicating that the induction of HSPs did not affect protein aggregation or charge variants. These findings suggest that inducing and manipulating HSP expression can be a valuable strategy for improving recombinant protein production in biopharmaceutical processes.

Mono-quinoxaline-induced DNA structural alteration leads to ZBP1/RIP3/MLKL-driven necroptosis in cancer cells

Evading the cellular apoptosis mechanism by modulating multiple pathways poses a sturdy barrier to effective chemotherapy. Cancer cell adeptly resists the apoptosis signaling pathway by regulating anti and pro-apoptotic proteins to escape cell death. Nevertheless, bypassing the apoptotic pathway through necroptosis, an alternative programmed cell death process, maybe a potential therapeutic modality for apoptosis-resistant cells. However, synthetic mono-quinoxaline-based intercalator-induced cellular necroptosis as an anti-cancer perspective remains under-explored. To address this concern, we undertook the design and synthesis of quinoxaline-based small molecules (3a-3l). Our approach involved enhancing the π-surface of the mandatory benzyl moiety to augment its ability to induce DNA structural alteration via intercalation, thereby promoting cytotoxicity across various cancer cell lines (HCT116, HT-29, and HeLa). Notably, the potent compound 3a demonstrated the capacity to induce DNA damage in cancer cells, leading to the induction of ZBP1-mediated necroptosis in the RIP3-expressed cell line (HT-29), where Z-VAD effectively blocked apoptosis-mediated cell death. Interestingly, we observed that 3a induced RIP3-driven necroptosis in combination with DNA hypomethylating agents, even in the RIP3-silenced cell lines (HeLa and HCT116). Overall, our synthesized compound 3a emerged as a promising candidate against various cancers, particularly in apoptosis-compromised cells, through the induction of necroptosis.

Drug-Loaded Polydopamine Nanoparticles for Chemo/Photothermal Therapy against Colorectal Cancer Cells

Colorectal cancer (CRC) is a common and deadly malignancy, ranking second in terms of mortality and third in terms of incidence on a global scale. The survival rates for CRC patients are unsatisfactory primarily because of the absence of highly effective clinical strategies. The efficacy of existing CRC treatments, such as chemotherapy (CT), is constrained by issues such as drug resistance and damage to healthy tissues. Alternative approaches such as photothermal therapy (PTT), while offering advantages over traditional therapies, suffer instead from a low efficiency in killing tumor cells when used alone. In this context, nanostructures can efficiently contribute to a selective and targeted treatment. Here, we combined CT and PTT by developing a nanoplatform based on polydopamine nanoparticles (PDNPs), selected for their biocompatibility, drug-carrying capabilities, and ability to produce heat upon exposure to near-infrared (NIR) irradiation. As a chemotherapy drug, sorafenib has been selected, a multikinase inhibitor already approved for clinical use. By encapsulating sorafenib in polydopamine nanoparticles (Sor-PDNPs), we were able to successfully improve the drug stability in physiological media and the consequent uptake by CRC cells, thereby increasing its therapeutic effects. Upon NIR stimulus, Sor-PDNPs can induce a temperature increment of about 10 °C, encompassing both PTT and triggering a localized and massive drug release. Sor-PDNPs were tested on healthy colon cells, showing minimal adverse outcomes; conversely, they demonstrated excellent efficacy against CRC cells, with a strong capability to hinder cancer cell proliferation and induce apoptosis. Obtained findings pave the way to new synergistic chemo-photothermal approaches, maximizing the therapeutic outcomes against CRC while minimizing side effects on healthy cells.

Netrin-1 inducing antiapoptotic effect of acute myeloid leukemia cells in a concentration-dependent manner through the Unc-5 netrin receptor B-focal adhesion kinase axis

Acute myeloid leukemia (AML) is a hematological malignancy that commonly occurs in children. The prognosis of pediatric AML is relatively poor, thus threatening the patient's survival. The aberrant expression of the axon guidance factor, netrin-1, is observed in various types of malignancies, and it participates in the proliferation and apoptosis of tumor cells. Herein, we aimed to explore the role of netrin-1 in AML cells. Netrin-1 is highly expressed in AML patients. Proliferation and anti-apoptosis were observed in AML cells treated with netrin-1. The interaction between netrin-1 and Unc-5 netrin receptor B (UNC5B) was detected through coimmunoprecipitation, and UNC5B ribonucleic acid interference restrained the influence of netrin-1 on the AML cells. The phosphorylation of focal adhesion kinase-protein kinase B (FAK-Akt) was upregulated in AML cells treated with netrin-1. Both FAK and Akt inhibitors abrogated the effects of netrin-1 on the proliferation and apoptosis of AML cells. In conclusion, netrin-1 could promote the growth and reduce the apoptosis of AML cells in a concentration-dependent manner, and that these effects were mediated by activating the FAK-Akt signaling pathway via the UNC5B.

Salivary Gland Bioengineering

Salivary gland dysfunction affects millions globally, and tissue engineering may provide a promising therapeutic avenue. This review delves into the current state of salivary gland tissue engineering research, starting with a study of normal salivary gland development and function. It discusses the impact of fibrosis and cellular senescence on salivary gland pathologies. A diverse range of cells suitable for tissue engineering including cell lines, primary salivary gland cells, and stem cells are examined. Moreover, the paper explores various supportive biomaterials and scaffold fabrication methodologies that enhance salivary gland cell survival, differentiation, and engraftment. Innovative engineering strategies for the improvement of vascularization, innervation, and engraftment of engineered salivary gland tissue, including bioprinting, microfluidic hydrogels, mesh electronics, and nanoparticles, are also evaluated. This review underscores the promising potential of this research field for the treatment of salivary gland dysfunction and suggests directions for future exploration.

Recent advancements in nanomedicine based lipid metabolism for tumour immunotherapy

Therapy on lipid metabolism is emerging as a groundbreaking cancer treatment, offering the unprecedented opportunity to effectively treat and in several cases. Tumorigenesis is inextricably linked to lipid metabolism. In this regard, the features of lipid metabolism include lipid synthesis, decomposition, metabolism and lipid storage and mobilisation from intracellular lipid droplets. Most importantly, the regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects. Different cancers and immune cells have different dependence on lipid metabolism, playing a pivotal role in differentiation and function of immune cells. However, what lies before the immunotherapy targeting lipid metabolism is side effects of systemic toxicity and defects of individual drugs, which strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies. This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells and their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.HighlightsThe regulation of lipid metabolism is central to the appropriate immune response of tumour cells, and ultimately to exert the immune efforts to realise the perspective of many anti-tumour effects.Preparations of focusing lipid metabolism have side effects of systemic toxicity and defects of individual drugs. It strongly highlights that nanodelivery strategy is a magnet for it to enhance drug efficiency, reduce drug toxicity and improve application deficiencies.This review will first focus on emerging research progress of lipid metabolic reprogramming mechanism, and then explore the complex role of lipid metabolism in the tumour cells including the effect on immune cells as well as their nano-preparations of monotherapy and multiple therapies used in combination, in a shift away from conventional cancer research.

Dual Implications of Nanosilver-Induced Autophagy: Nanotoxicity and Anti-Cancer Effects

In recent years, efforts have been made to identify new anti-cancer therapies. Various types of nanomaterials, including silver nanoparticles (AgNPs), are being considered as an option. In addition to its well-known antibacterial activity, AgNPs exhibit cytotoxic potential in both physiological and cancer cells by inducing stress-mediated autophagy and apoptotic cell death. A rapidly growing collection of data suggests that the proper regulation of autophagic machinery may provide an efficient tool for suppressing the development of cancer. In this light, AgNPs have emerged as a potential anti-cancer agent to support therapy of the disease. This review summarizes current data indicating the dual role of AgNP-induced autophagy and highlights factors that may influence its protective vs. its toxic potential. It also stresses that our understanding of the cellular and molecular mechanisms of autophagy machinery in cancer cells, as well as AgNP-triggered autophagy in both normal and diseased cells, remains insufficient.

Transferrin-Targeted Liposomes in Glioblastoma Therapy: A Review

Glioblastoma (GBM) is a highly aggressive brain tumor, and its treatment is further complicated by the high selectivity of the blood-brain barrier (BBB). The scientific community is urgently seeking innovative and effective therapeutic solutions. Liposomes are a promising new tool that has shown potential in addressing the limitations of chemotherapy, such as poor bioavailability and toxicity to healthy cells. However, passive targeting strategies based solely on the physicochemical properties of liposomes have proven ineffective due to a lack of tissue specificity. Accordingly, the upregulation of transferrin receptors (TfRs) in brain tissue has led to the development of TfR-targeted anticancer therapeutics. Currently, one of the most widely adopted methods for improving drug delivery in the treatment of GBM and other neurological disorders is the utilization of active targeting strategies that specifically target this receptor. In this review, we discuss the role of Tf-conjugated liposomes in GBM therapy and present some recent studies investigating the drug delivery efficiency of Tf-liposomes; in addition, we address some challenges currently facing this approach to treatment and present some potential improvement possibilities.

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.

Novel 2-alkythio-4-chloro-N-[imino(heteroaryl)methyl]benzenesulfonamide Derivatives: Synthesis, Molecular Structure, Anticancer Activity and Metabolic Stability

A series of novel 2-alkythio-4-chloro-N-[imino-(heteroaryl)methyl]benzenesulfonamide derivatives, 8-24, were synthesized in the reaction of the N-(benzenesulfonyl)cyanamide potassium salts 1-7 with the appropriate mercaptoheterocycles. All the synthesized compounds were evaluated for their anticancer activity in HeLa, HCT-116 and MCF-7 cell lines. The most promising compounds, 11-13, molecular hybrids containing benzenesulfonamide and imidazole moieties, selectively showed a high cytotoxic effect in HeLa cancer cells (IC₅₀: 6-7 μM) and exhibited about three times less cytotoxicity against the non-tumor cell line HaCaT cells (IC₅₀: 18-20 μM). It was found that the anti-proliferative effects of 11, 12 and 13 were associated with their ability to induce apoptosis in HeLa cells. The compounds increased the early apoptotic population of cells, elevated the percentage of cells in the sub-G1 phase of the cell cycle and induced apoptosis through caspase activation in HeLa cells. For the most active compounds, susceptibility to undergo first-phase oxidation reactions in human liver microsomes was assessed. The results of the in vitro metabolic stability experiments indicated values of the factor t_½ for 11-13 in the range of 9.1-20.3 min and suggested the hypothetical oxidation of these compounds to sulfenic and subsequently sulfinic acids as metabolites.

Targeting multifunctional magnetic nanowires for drug delivery in cancer cell death: an emerging paradigm

Apoptosis, often known as programmed cell death is a mechanism used by numerous species to maintain tissue homeostasis. The process leading to cell death is complicated because it requires the stimulation of caspases. According to several studies, nanowires have important medical benefits, can kill cells by adhering to cancer cells, destroying them, and killing the entire cell using a triple attack that integrates vibration, heat, and drug delivery to trigger apoptosis. The sewage effluents and industrial, fertilizer and organic wastes decomposition can produce elevated levels of chemicals in the environment which may interrupt the cell cycle and activate apoptosis. The purpose of this review is to give a thorough summary of the evidence that is currently available on apoptosis. Current review discussed topics like the morphological and biochemical alterations that occur during apoptosis, as well as the various mechanisms that cause cell death, including the intrinsic (or mitochondrial), extrinsic (or death receptor), and intrinsic endoplasmic reticulum pathway. The apoptosis reduction in cancer development is mediated by (i) an imbalance between pro- and anti-apoptotic proteins, such as members of the B-cell lymphoma-2 (BCL2) family of proteins, tumour protein 53 and inhibitor of apoptosis proteins, (ii) a reduction in caspase activity, and (iii) impaired death receptor signalling. This review does an excellent task of outlining the function of nanowires in both apoptosis induction and targeted drug delivery for cancer cells. A comprehensive summary of the relevance of nanowires synthesised for the purpose of inducing apoptosis in cancer cells has been compiled collectively.

Photochemical Targeting of Mitochondria to Overcome Chemoresistance in Ovarian Cancer †

Ovarian cancer is the most lethal gynecologic malignancy with a stubborn mortality rate of ~65%. The persistent failure of multiline chemotherapy, and significant tumor heterogeneity, has made it challenging to improve outcomes. A target of increasing interest is the mitochondrion because of its essential role in critical cellular functions, and the significance of metabolic adaptation in chemoresistance. This review describes mitochondrial processes, including metabolic reprogramming, mitochondrial transfer and mitochondrial dynamics in ovarian cancer progression and chemoresistance. The effect of malignant ascites, or excess peritoneal fluid, on mitochondrial function is discussed. The role of photodynamic therapy (PDT) in overcoming mitochondria-mediated resistance is presented. PDT, a photochemistry-based modality, involves the light-based activation of a photosensitizer leading to the production of short-lived reactive molecular species and spatiotemporally confined photodamage to nearby organelles and biological targets. The consequential effects range from subcytotoxic priming of target cells for increased sensitivity to subsequent treatments, such as chemotherapy, to direct cell killing. This review discusses how PDT-based approaches can address key limitations of current treatments. Specifically, an overview of the mechanisms by which PDT alters mitochondrial function, and a summary of preclinical advancements and clinical PDT experience in ovarian cancer are provided.

Review on Metal-Based Theranostic Nanoparticles for Cancer Therapy and Imaging

Theranostic agents are promising due to their ability to diagnose, treat and monitor different types of cancer using a variety of imaging modalities. The advantage specifically of nanoparticles is that they can accumulate easily at the tumor site due to the large gaps in blood vessels near tumors. Such high concentration of theranostic agents at the target site can lead to enhancement in both imaging and therapy. This article provides an overview of nanoparticles that have been used for cancer theranostics, and the different imaging, treatment options and signaling pathways that are important when using nanoparticles for cancer theranostics. In particular, nanoparticles made of metal elements are emphasized due to their wide applications in cancer theranostics. One important aspect discussed is the ability to combine different types of metals in one nanoplatform for use as multimodal imaging and therapeutic agents for cancer.

Balance Cell Apoptosis and Pyroptosis of Caspase-3-Activating Chemotherapy for Better Antitumor Therapy

Chemotherapy is a standard treatment modality in clinic that exerts an antitumor effect via the activation of the caspase-3 pathway, inducing cell death. While a number of chemotherapeutic drugs have been developed to combat various types of tumors, severe side effects have been their common limitation, due to the nonspecific drug biodistribution, bringing significant pain to cancer patients. Recently, scientists found that, besides apoptosis, chemotherapy could also cause cell pyroptosis, both of which have great influence on the therapeutic index. For example, cell apoptosis is, generally, regarded as the main mechanism of killing tumor cells, while cell pyroptosis in tumors promotes treatment efficacy, but in normal tissue results in toxicity. Therefore, significant research efforts have been paid to exploring the rational modulation mode of cell death induced by chemotherapy. This critical review aims to summarize recent progress in the field, focusing on how to balance cell apoptosis and pyroptosis for better tumor chemotherapy. We first reviewed the mechanisms of chemotherapy-induced cell apoptosis and pyroptosis, in which the activated caspase-3 is the key signaling molecule for regulating both types of cell deaths. Then, we systematically discussed the rationale and methods of switching apoptosis to pyroptosis for enhanced antitumor efficacy, as well as the blockage of pyroptosis to decrease side effects. To balance cell pyroptosis in tumor and normal tissues, the level of GSDME expression and tumor-targeting drug delivery are two important factors. Finally, we proposed potential future research directions, which may provide guidance for researchers in the field.

Exploring the recent trends in perturbing the cellular signaling pathways in cancer by natural products

Cancer is commonly thought to be the product of irregular cell division. According to the World Health Organization (WHO), cancer is the major cause of death globally. Nature offers an abundant supply of bioactive compounds with high therapeutic efficacy. Anticancer effects have been studied in a variety of phytochemicals found in nature. When Food and Drug Administration (FDA)-approved anticancer drugs are combined with natural compounds, the effectiveness improves. Several agents have already progressed to clinical trials based on these promising results of natural compounds against various cancer forms. Natural compounds prevent cancer cell proliferation, development, and metastasis by inducing cell cycle arrest, activating intrinsic and extrinsic apoptosis pathways, generating reactive oxygen species (ROS), and down-regulating activated signaling pathways. These natural chemicals are known to affect numerous important cellular signaling pathways, such as NF-B, MAPK, Wnt, Notch, Akt, p53, AR, ER, and many others, to cause cell death signals and induce apoptosis in pre-cancerous or cancer cells without harming normal cells. As a result, non-toxic “natural drugs” taken from nature’s bounty could be effective for the prevention of tumor progression and/or therapy of human malignancies, either alone or in combination with conventional treatments. Natural compounds have also been shown in preclinical studies to improve the sensitivity of resistant cancers to currently available chemotherapy agents. To summarize, preclinical and clinical findings against cancer indicate that natural-sourced compounds have promising anticancer efficacy. The vital purpose of these studies is to target cellular signaling pathways in cancer by natural compounds.

Detection of netrin-1 as a novel biomarker for diagnosis and chemotherapeutic monitoring of lung cancer

Objective

Lung cancer has high morbidity and mortality. We aimed to determine the value of netrin-1 for the diagnosis and chemotherapeutic monitoring of lung cancer.

Methods

Thirty pairs of lung cancer tissues and serum were collected. Netrin-1 expression was detected by immunohistochemistry and enzyme-linked immunosorbent assay. Netrin-1 expression was downregulated in A549 cells using small interfering RNA, and the effect of netrin-1 on cisplatin-induced lung cancer cell apoptosis was determined by flow cytometry.

Results

Netrin-1-positivity was significantly higher in lung cancer tissues than in paracarcinoma tissues and high expression of netrin-1 was closely related to a poor prognosis. Serum netrin-1 levels were also significantly higher in lung cancer patients than in healthy donors, and were higher in patients with lung cancer before the beginning of chemotherapy compared with after the completion of four cycles of chemotherapy. Netrin-1 knockdown increased the rate of cisplatin-induced apoptosis in A549 cells.

Conclusions

Netrin-1 expression was increased in tissues and serum from lung cancer patients and decreased after chemotherapy, suggesting that it may be a potential diagnostic marker and indicator of chemosensitivity. Netrin-1 may participate in cisplatin resistance by reducing apoptosis, thus providing a new strategy for addressing chemoresistance in patients with lung cancer.

Nanocarriers as a Tool for the Treatment of Colorectal Cancer

Nanotechnology is a promising tool for the treatment of cancer. In the past decades, major steps have been made to bring nanotechnology into the clinic in the form of nanoparticle-based drug delivery systems. The great hope of drug delivery systems is to reduce the side effects of chemotherapeutics while simultaneously increasing the efficiency of the therapy. An increased treatment efficiency would greatly benefit the quality of life as well as the life expectancy of cancer patients. However, besides its many advantages, nanomedicines have to face several challenges and hurdles before they can be used for the effective treatment of tumors. Here, we give an overview of the hallmarks of cancer, especially colorectal cancer, and discuss biological barriers as well as how drug delivery systems can be utilized for the effective treatment of tumors and metastases.

Role of 4-Thiazolidinone Scaffold in Targeting Variable Biomarkers and Pathways Involving Cancer

BACKGROUND

Cancer can be considered as a genetic as well as a metabolic disorder. Current cancer treatment scenario looks like aggravating tumor cell metabolism, causing the disease to progress even with greater intensity. The cancer therapy is restricted to limitations of poor patient compliance due to toxicities to normal tissues and multi-drug resistance development. There is an emerging need for cancer therapy to be more focused on the better understanding of genetic, epigenetic and transcriptional changes resulting in cancer progression and their relationship with treatment sensitivity.

OBJECTIVE

The 4-thiazolidinone nucleus possesses marked anticancer potential towards different biotargets, thus targeting different cancer types like breast, prostate, lung, colorectal and colon cancers, renal cell adenocarcinomas and gliomas. Therefore, conjugating the 4-thiazolidinone scaffold with other promising moieties or by directing the therapy towards targeted drug delivery systems like the use of nanocarrier systems, can provide the gateway for optimizing the anticancer efficiency and minimizing the adverse effects and drug resistance development, thus providing stimulus for personalized pharmacotherapy.

METHODS

An exhaustive literature survey has been carried out to give an insight into the anticancer potential of the 4-thiazolidinone nucleus either alone or in conjugation with other active moieties, with the mechanisms involved in preventing proliferation and metastasis of cancer covering a vast range of publications of repute.

CONCLUSION

This review aims to summarise the work reported on anticancer activity of 4-thiazolidinone derivatives covering various cancer biomarkers and pathways involved, citing the data from 2005 till now, which may be beneficial to the researchers for future development of more efficient 4-thiazolidinone derivatives.

Pre-Treatment of Pterostilbene Enhances H2O2-induced Cell Apoptosis Through Caspase-dependent Pathway in Human Keratinocyte Cells

BACKGROUND/AIM

Hydrogen peroxide (H₂O₂) is one of the reactive oxygen species (ROS), which can induce apoptotic cell death in numerous cancer cells. Pterostilbene (PTE), a natural polyphenolic compound, induces cell apoptosis in many human cancer cells.

MATERIALS AND METHODS

We investigated whether PTE could enhance H₂O₂-induced cell apoptosis in human keratinocyte HaCaT cells in vitro. The morphological change of HaCaT cells was observed and photographed under a contrast-phase microscope. The percentage of cell viability was measured by propidium iodide exclusion assay. Cell apoptosis was performed by Annexin V/PI double staining and assayed by flow cytometer. DNA condensation was measured by DAPI staining. The protein expression was determined by western blotting. ROS production-associated proteins were also assayed by confocal laser scanning microscopy.

RESULTS

PTE pre-treatment enhanced H₂O₂ (600 μM)-induced cell morphological changes and reduced the total cell number (cell viability). The decreased cell viability in HaCaT cells was through induction of apoptotic cell death, which was confirmed by Annexin V/PI double staining and DAPI staining. Western blotting studies indicated that HaCaT cells which were pre-treated with PTE (100 μM) and then co-treated with H₂O₂ (600 μM) for 12 h showed significantly increased levels of SOD (Cu/Zn), SOD (Mn), Bax, caspase-3, caspase-8, caspase-9, PARP, p53, p-p53, and p-H2A.X but decreased levels Bcl-2 and catalase. Results also showed that HaCaT cells pre-treated with PTE and then co-treated with H₂O₂ had increased expression of SOD (Cu/Zn) and glutathione but decreased catalase.

CONCLUSION

These observations suggest that PTE pre-treatment can enhance the H₂O₂-induced apoptotic cell death in keratinocyte cells and may be an effective candidate for the treatment of proliferative keratinocytes.

In vitro Anti-colorectal Cancer Potential of the Medicinal Mushroom Ganoderma neo-japonicum Imazeki in Hyperglycemic Condition: Impact on Oxidative Stress, Cell Cycle and Apoptosis

Clinical efficacy of chemotherapy is often compromised by diabetogenic glucose on colorectal cancer (CRC). High glucose has been shown to diminish the cytotoxicity of anticancer drugs. The issue can potentially be addressed with natural products. Recently, we revealed that Ganoderma neo-japonicum exhibits inhibitory activities against human colonic carcinoma cells. In this study, the impacts of hexane fraction (Hex, sterol-enriched) and chloroform fraction (Chl, terpenoid-enriched) were further elucidated. The cellular responses, including oxidative stress, cell cycle, and apoptosis were compared between the presence of normal glucose (NG, 5.5 mM) and high glucose (HG, 25 mM). HG promoted cell viability with concomitant elevation of GSH level. Both Hex and Chl fractions stimulated NO production, in addition, induced cell cycle arrest. The apoptotic effect of Hex fraction was glucose-dependent, but Chl fraction triggered apoptosis with an equivalent extent in NG and HG conditions. Overall, the active fractions from G. neo-japonicum show therapeutic potential in managing hyperglycemia-associated CRC.

A novel phosphoramide compound, DCZ0805, shows potent anti-myeloma activity via the NF-κB pathway

BACKGROUND

Multiple myeloma (MM) is a highly aggressive and incurable clonal plasma cell disease with a high rate of recurrence. Thus, the development of new therapies is urgently needed. DCZ0805, a novel compound synthesized from osalmide and pterostilbene, has few observed side effects. In the current study, we intend to investigate the therapeutic effects of DCZ0805 in MM cells and elucidate the molecular mechanism underlying its anti-myeloma activity.

METHODS

We used the Cell Counting Kit-8 assay, immunofluorescence staining, cell cycle assessment, apoptosis assay, western blot analysis, dual-luciferase reporter assay and a tumor xenograft mouse model to investigate the effect of DCZ0805 treatment both in vivo and in vitro.

RESULTS

The results showed that DCZ0805 treatment arrested the cell at the G0/G1 phase and suppressed MM cells survival by inducing apoptosis via extrinsic and intrinsic pathways. DCZ0805 suppressed the NF-κB signaling pathway activation, which may have contributed to the inhibition of cell proliferation. DCZ0805 treatment remarkably reduced the tumor burden in the immunocompromised xenograft mouse model, with no obvious toxicity observed.

CONCLUSION

The findings of this study indicate that DCZ0805 can serve as a novel therapeutic agent for the treatment of MM.

β-Glucan: A dual regulator of apoptosis and cell proliferation

β-Glucans are polysaccharides generally obtained from the cell wall of bacteria, fungi, yeasts, and aleurone layer of cereals. β-Glucans are polymers, with β-1,3 glucose as core linear structure, but they differ in their main branch length, linkages and branching patterns, giving rise to high and low-molecular-weight β-glucans. They are well-known cell response modifiers with immune-modulating, nutraceutical and health beneficial effects, including anticancer and pro-apoptotic properties. β-Glucan extracts have shown positive responses in controlling tumor cell proliferation and activation of the immune system. The immunomodulatory action of β-glucans enhances the host's antitumor defense against cancer. In consonance with the above, many studies have shown that β-glucan treatment leads to the induction of apoptotic death of cancer cells. The ability of β-glucans to stimulate apoptotic pathways or the proteins involved in apoptosis prompting a new domain in cancer therapy. β-glucan can be a potential therapeutic agent for the treatment of cancer. However, there is a need to legitimize the β-glucan type, as most of the studies include β-glucan from different sources having different physicochemical properties. The body of literature presented here focuses on the effects of β-glucan on immunomodulation, proliferation, cell death and the possible mechanisms and pathways involved in these processes.

Physcion and Physcion 8-O-β-D-glucopyranoside: Natural Anthraquinones with Potential Anticancer Activities

Nature has provided prodigious reservoirs of pharmacologically active compounds for drug development since times. Physcion and physcion 8-O-β-D-glucopyranoside (PG) are bioactive natural anthraquinones which exert anti-inflammatory and anticancer properties with minimum or no adverse effects. Moreover, physcion also exhibits anti-microbial and hepatoprotective properties, while PG is known to have anti-sepsis as well as ameliorative activities against dementia. This review aims to highlight the natural sources and anticancer activities of physcion and PG, along with associated mechanisms of actions. On the basis of the literature, physcion and PG regulate multitudinous cell signaling pathways through the modulation of various regulators of cell cycle, protein kinases, microRNAs, transcriptional factors, and apoptosis linked proteins resulting in the effective killing of cancerous cells in vitro as well as in vivo. Both compounds effectively suppress metastasis, furthermore, physcion acts as an inhibitor of 6PGD and also plays an important role in chemosensitization. This review article suggests that physcion and PG are potent anticancer drug candidates, but further investigations on their mechanism of action and pre-clinical trials are mandatory in order to comprehend the full potential of these natural cancer killers in anticancer remedies.

Nimbolide induces cell death in T lymphoma cells: Implication of altered apoptosis and glucose metabolism

Nimbolide is a tetranortriterpenoid derived from the leaves and flowers of Azadirachta indica (Neem). It exhibits anticancer activity against a variety of cancers by modulating various crucial features, including cell proliferation, apoptosis, and invasion and metastasis. More importantly, the cytotoxic effect of nimbolide has also been observed against T cell lymphoma, but the underlying mechanisms are still unexplored. So far, no study has been conducted to observe the effect of nimbolide on cancer cell metabolism. Therefore, the present investigation was designed to explore the molecular mechanisms of the antitumor potential of nimbolide against T cell lymphoma, a neoplastic disorder of thymic origin. In addition, we also unraveled the anti-glycolytic activity of nimbolide against T lymphoma cells with possible molecular mechanisms. Our results showed the cytotoxic action of nimbolide against three different cell lines of T cell lymphoma, namely Dalton's lymphoma, HuT-78, and J6. Nimbolide-induced apoptosis in T lymphoma cells by altering the level of reactive oxygen species, p53, Bcl2, Bax, and cytochrome c, with subsequent cleavage of caspase 3. Remarkably, nimbolide inhibited the expression of hypoxia-inducible factor-1α, glucose transporter 3, hexokinase II, and pyruvate dehydrogenase kinase 1, which led to the suppression of glycolysis with concomitant activation of oxidative phosphorylation. Hence, the results of the present investigation demonstrate that nimbolide exerts tumoricidal activity against T lymphoma cells via augmentation of apoptosis and reversal of altered cell metabolism. Thus, the present study provides a new insight for the therapeutic utilization of nimbolide against T cell lymphoma.

4-Vinylguaiacol, an Active Metabolite of Ferulic Acid by Enteric Microbiota and Probiotics, Possesses Significant Activities against Drug-Resistant Human Colorectal Cancer Cells

Ferulic acid, a hydroxycinnamic acid, is abundant in vegetables, grains, and medicinal plants. Emerging evidence suggests that ferulic acid may exert beneficial effects against colorectal cancer. However, the anticancer activity of ferulic acid is relatively low, and its metabolism after oral administration is largely unknown. In this study, mimicking the enteric environment, human intestinal microflora and commercial probiotics were used to metabolize ferulic acid to its metabolites, and their anticancer activities were evaluated. Ferulic acid can be biotransformed to 4-vinylguaiacol (2-methoxy-4-vinylphenol), and the contents of ferulic acid and 4-vinylguaiacol in bio-transformed extracts were determined by high-performance liquid chromatography (HPLC). Using the chemotherapy-sensitive cell line HCT-116 and the chemo-resistant cell line HT-29, the cell proliferation was determined by the modified trichrome stain assay. The cell cycle and induction of apoptosis were assayed using flow cytometry. HPLC data showed that there was a marked transformation from ferulic acid to 4-vinylguaiacol, and the conversion rates of intestinal microflora and four probiotics were from 1.3 to 36.8%. Both ferulic acid and 4-vinylguaiacol possessed dose- and time-related anticancer activities on the two cell lines, while 4-vinylguaiacol showed more potent effects than ferulic acid. Interestingly, 4-vinylguaiacol exhibited significantly higher antiproliferative effects on the HT-29 cell line than that on HCT-116. The IC50 of the metabolite 4-vinylguaiacol on HT-29 cells was 350 μM, 3.7-fold higher than its parent compound. The potential of cancer cell growth inhibition of 4-vinylguaiacol was mediated by cell cycle arrest at the G1 phase and induction of apoptosis. Data from this study indicate that the oral administration of ferulic acid offers a promising approach to increase its anticancer activity through gut microbial conversion to 4-vinylguaiacol, and the biotransformation could also be achieved by selected commercial probiotics. 4-Vinylguaiacol is a potential anticancer metabolite from ferulic acid for chemotherapy-resistant colon cancer cells.

Effects of tyrosine kinase inhibitors on thyroid function and thyroid hormone metabolism

The increasing knowledge of the molecular mechanisms in the cell signaling pathways of malignant cells, has recently led to the discovery of several tyrosine kinases (TKs), mainly TK receptors (TKR), which play a major role in the pathogenesis of many types of cancer. These receptors, physiologically involved in cell growth and angiogenesis, may harbor mutations or be overexpressed in malignant cells, and represent a target for anticancer therapy. Indeed, several therapeutic agents targeting specific altered pathways such as RET, BRAF, RAS, EGFR and VEGFR, have been identified. Tyrosine kinase inhibitors (TKIs) affect TK dependent oncogenic pathways by competing with ATP binding sites of the TK domain, thus blocking the activity of the enzyme, and thereby inhibiting the growth and spread of several cancers. Although the therapeutic action may be very effective, these molecules, due to their mechanism of multitargeted inhibition, may produce adverse events involving several biological systems. Both hypothyroidism and thyrotoxicosis have been reported during treatment with TKI, as well as an effect on the activity of enzymes involved in thyroid hormone metabolism. The pathogenic mechanisms leading to thyroid dysfunction and changes in serum thyroid function tests occurring in patients on TKI are reviewed and discussed in this manuscript.

High-Throughput Magnetic Actuation Platform for Evaluating the Effect of Mechanical Force on 3D Tumor Microenvironment

Accurately replicating and analyzing cellular responses to mechanical cues is vital for exploring metastatic disease progression. However, many of the existing in vitro platforms for applying mechanical stimulation seed cells on synthetic substrates. To better recapitulate physiological conditions, a novel actuating platform is developed with the ability to apply tensile strain on cells at various amplitudes and frequencies in a high-throughput multi-well culture plate using a physiologically-relevant substrate. Suspending fibrillar fibronectin across the body of the magnetic actuator provides a matrix representative of early metastasis for 3D cell culture that is not reliant on a synthetic substrate. This platform enables the culturing and analysis of various cell types in an environment that mimics the dynamic stretching of lung tissue during normal respiration. Metabolic activity, YAP activation, and morphology of breast cancer cells are analyzed within one week of cyclic stretching or static culture. Further, matrix degradation is significantly reduced in breast cancer cell lines with metastatic potential after actuation. These new findings demonstrate a clear suppressive cellular response due to cyclic stretching that has implications for a mechanical role in the dormancy and reactivation of disseminated breast cancer cells to macrometastases.

A novel TGF-β receptor II mutation (I227T/N236D) promotes aggressive phenotype of oral squamous cell carcinoma via enhanced EGFR signaling

Background

Transforming growth factor-β (TGF-β) signaling is a double-edged sword in cancer development and progression. TGF-β signaling plays a tumor suppressive role during the early stages of tumor development but promotes tumor progression in later stages. We have previously identified various mutations of TGF-β receptor II (TβRII) in human oral squamous cell carcinoma (OSCC) samples. In the present study we analyzed I227T/N236D mutation of TβRII, which was detected in the metastatic lymph node of an OSCC patient.

Methods

The effect of I227T/N236D TβRII mutation on transcriptional activities was measured using DR26 cells, which lack functional TβRII. HSC2 human OSCC cells stably expressing wild-type and I227T/N236D mutant TβRII were generated and used to examine the effect of I227T/N236D TβRII mutation on xenograft tumor growth, in vitro cell proliferation, apoptosis, migration, and invasion.

Results

The I227T/N236D mutation of TβRII upregulated TGF-β signaling and promoted xenograft tumor growth when compared with the wild-type, without affecting the in vitro proliferative capacities. To delineate the differences in proliferative capacities in vivo and in vitro, the apoptotic and survival signals were analyzed following curcumin treatment. Concomitant with apoptotic induction, epidermal growth factor receptor (EGFR) activation was observed upon curcumin treatment, which was further activated in I227T/N236D mutant transfectant cells when compared with wild-type cells. Enhanced EGFR activation correlated with cell survival and apoptotic resistance. Enhanced migratory and invasive capabilities of I227T/N236D mutant cells also depended on EGFR signaling.

Conclusions

These results suggest that enhanced EGFR signaling via upregulated TGF-β signaling shifted the balance toward survival and promoted cell migration and invasion in I227T/N236D mutant cells, elucidating the role of I227T/N236D mutation of TβRII in OSCC progression.

Induction of Apoptosis by Coptisine in Hep3B Hepatocellular Carcinoma Cells through Activation of the ROS-Mediated JNK Signaling Pathway

Hepatocellular carcinoma (HCC) has a high mortality rate worldwide, and treatment is very limited due to its high recurrence and low diagnosis rate, and therefore there is an increasing need to develop more effective drugs to treat HCC. Coptisine is one of the isoquinoline alkaloids, and it has various pharmacological effects. However, the evidence for the molecular mechanism of the anticancer efficacy is still insufficient. Therefore, this study investigated the antiproliferative effect of coptisine on human HCC Hep3B cells and identified the action mechanism. Our results showed that coptisine markedly increased DNA damage and apoptotic cell death, which was associated with induction of death receptor proteins. Coptisine also significantly upregulated expression of proapoptotic Bax protein, downregulated expression of anti-apoptotic Bcl-2 protein, and activated caspase-3, -8, and -9. In addition, coptisine remarkably increased the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential (MMP), and release of cytochrome c into the cytoplasm. However, N-acetylcysteine (NAC), a ROS scavenger, significantly attenuated the apoptosis-inducing effect of coptisine. It is worth noting that coptisine significantly upregulated phosphorylation of ROS-dependent c-Jun N-terminal kinase (JNK), whereas treatment with JNK inhibitor could suppress an apoptosis-related series event. Taken together, our results suggest that coptisine has an anticancer effect in Hep3B cells through ROS-mediated activation of the JNK signaling pathway.

Expression of HTRA Genes and Its Association with Microsatellite Instability and Survival of Patients with Colorectal Cancer

HtrA proteases regulate cellular homeostasis and cell death. Their dysfunctions have been correlated with oncogenesis and response to therapeutic treatment. We investigated the relation between HtrA1-3 expression and clinicopathological, and survival data, as well as the microsatellite status of tumors. Sixty-five colorectal cancer patients were included in the study. The expression of HTRA1-3 was estimated at the mRNA and protein levels by quantitative PCR and immunoblotting. Microsatellite status was determined by high-resolution-melting PCR. We found that the HTRA1 mRNA level was higher in colorectal cancer tissue as compared to the unchanged mucosa, specifically in primary lesions of metastasizing cancer. The levels of HtrA1 and HtrA2 proteins were reduced in tumor tissue when compared to unchanged mucosa, specifically in primary lesions of metastasizing disease. Moreover, a decrease in HTRA1 and HTRA2 transcripts' levels in cancers with a high level of microsatellite instability compared to microsatellite stable ones has been observed. A low level of HtrA1 or/and HtrA2 in cancer tissue correlated with poorer patient survival. The expression of HTRA1 and HTRA2 changes during colorectal carcinogenesis and microsatellite instability may be, at least partially, associated with these changes. The alterations in the HTRA1/2 genes' expression are connected with metastatic potential of colorectal cancer and may affect patient survival.

Effect of Lactobacillus acidophilus CICC 6074 S-Layer Protein on Colon Cancer HT-29 Cell Proliferation and Apoptosis

The objective of this research was to investigate the effects of Lactobacillus acidophilus CICC 6074 S-layer protein on the viability, adhesion, cell cycle, and apoptosis of human colon cancer HT-29 cells and to explore their molecular mechanism of tumor suppression. The S-layer protein at doses of 0, 25, 50, and 100 mg/L significantly suppressed the proliferation of HT-29 cells. The S-layer protein exerts its cytotoxic activities against colon cancer HT-29 cells by arresting the cell cycle in the G1 phase through upregulating the expression of p53, p21, and p16 and downregulating the expression of CDK1 (cyclin-dependent kinases) and cyclin B. Morphological changes were further observed by transmission electron microscopy, and the cells treated with the S-layer protein showed obvious characteristic changes of apoptosis including chromatin condensation, nuclear fragmentation, vacuoles, and so on. Furthermore, our mechanism studies indicated that the S-layer protein may induce HT-29 cell apoptosis through the death receptor apoptotic pathway and mitochondrial pathway and impede cell invasion by inhibiting the synthesis of the PI3K/AKT pathway and FasL. These results demonstrated that the L. acidophilus CICC 6074 S-layer protein may be a potential anticarcinogenic agent.

Downregulating integrin subunit alpha 7 (ITGA7) promotes proliferation, invasion, and migration of papillary thyroid carcinoma cells through regulating epithelial-to-mesenchymal transition

Thyroid cancer is one of the common malignancies of the endocrine system and the number of thyroid cancer cases is increasing constantly. Significant work has focused on the molecular mechanisms of thyroid cancer, but many mechanisms remain undiscovered. In this study, we employed a comprehensive analysis of whole-transcriptome resequencing derived from paired papillary thyroid cancer (PTC) and normal thyroid tissues. We performed a massive parallel whole-transcriptome resequencing of matched PTC and normal thyroid tissues in 19 patients and found that integrin subunit alpha 7 (ITGA7) was downregulated in thyroid tumor tissues, but the function of ITGA7 in this cancer is still unclear. We also discovered that ITGA7 gene in thyroid cancer tissues was downregulated compared to paired adjacent non-tumor tissues by real-time quantitative polymerase chain reaction. After transfection with small interfering RNA to knock down ITGA7, the abilities of colony formation, proliferation, migration, and invasion were enhanced in PTC cell lines (TPC1 and KTC-1). Meanwhile, ITGA7 knockdown decreased apoptotic cell death in thyroid cells but promoted the expressions of N-cadherin and vimentin and decreased E-cadherin expression by epithelial-to-mesenchymal transition, which may induce invasion and migration. In conclusion, these results indicated that ITGA7 is involved in the progress of PTC and might act as a tumor suppressor gene.

Rosiglitazone enhances the apoptotic effect of 5-fluorouracil in colorectal cancer cells with high-glucose-induced glutathione

Colorectal cancer is one of the most prevalent noncommunicable diseases worldwide. 5-Fluorouracil is the mainstay of chemotherapy for colorectal cancer. Previously, we have demonstrated that high glucose diminishes the cytotoxicity of 5-fluorouracil by promoting cell cycle progression. The synergistic impact of rosiglitazone on 5-fluorouracil-induced apoptosis was further investigated in this study. Besides control cell lines (CCD-18Co), two human colonic carcinoma cell lines (HCT 116 and HT 29) were exposed to different treatments containing 5-fluorouracil, rosiglitazone or 5-fluorouracil/rosiglitazone combination under normal glucose (5.5 mM) and high-glucose (25 mM) conditions. The cellular oxidative stress level was evaluated with biomarkers of nitric oxide, advanced oxidation protein products, and reduced glutathione. The cell apoptosis was assessed using flow cytometry technique. High glucose caused the production of reduced glutathione in HCT 116 and HT 29 cells. Correspondingly, high glucose suppressed the apoptotic effect of 5-fluorouracil and rosiglitazone. As compared to 5-fluorouracil alone (2 µg/mL), addition of rosiglitazone significantly enhanced the apoptosis (increment rate of 5-20%) in a dose-dependent manner at normal glucose and high glucose levels. This study indicates that high-glucose-induced reduced glutathione confers resistance to apoptosis, but it can be overcome upon treatment of 5-fluorouracil and 5-fluorouracil/rosiglitazone combination. Rosiglitazone may be a promising antidiabetic drug to reduce the chemotherapeutic dose of 5-fluorouracil for colorectal cancer complicated with hyperglycemia.

Nano-immunotherapy: Overcoming tumour immune evasion

Immunotherapy is emerging as a groundbreaking cancer treatment, offering the unprecedented opportunity to effectively treat and in several cases, even cure previously untreatable malignancies. Anti-tumour immunotherapies designed to amplify T cell responses against defined tumour antigens have long been considered effective approaches for cancer treatment. Despite a clear rationale behind such immunotherapies, extensive past efforts were unsuccessful in mediating clinically relevant anti-tumour activity in humans. This is mainly because tumours adopt specific mechanisms to circumvent the host´s immunity. Emerging data suggest that the full potential of cancer immunotherapy will be only achieved by combining immunotherapies designed to generate or amplify anti-tumour T cell responses with strategies able to impair key tumour immune-evasion mechanisms. However, many approaches aimed to re-shape the tumour immune microenvironment (TIME) are commonly associated with severe systemic toxicity, require frequent administration, and only show modest efficacy in clinical settings. The use of nanodelivery systems is revealing as a valid means to overcome these limitations by improving the targeting efficiency, minimising systemic exposure of immunomodulatory agents, and enabling the development of novel combinatorial immunotherapies. In this review, we examine the emerging field of therapeutic modulation of TIME by the use of nanoparticle-based immunomodulators and potential future directions for TIME-targeting nanotherapies.

Overcoming malignant cell-based mechanisms of resistance to immune checkpoint blockade antibodies

Traditional cancer treatment approaches have focused on surgery, radiation therapy, and cytotoxic chemotherapy. However, with rare exceptions, metastatic cancers were considered to be incurable by traditional therapy. Over the past 20 years a fourth modality - immunotherapy - has emerged as a potentially curative approach for patients with advanced metastatic cancer. However, in many patients cancer "finds a way" to evade the anti-tumor effects of immunotherapy. Immunotherapy resistance mechanisms can be employed by both cancer cells and the non-cancer elements of tumor microenvironment. This review focuses on the resistance mechanisms that are specifically mediated by cancer cells. In order to extend the impact of immunotherapy to more patients and across all cancer types, and to inhibit the development of acquired resistance, the underlying biology driving immune escape needs to be better understood. Elucidating mechanisms of immune escape may shed light on new therapeutic targets, and lead to successful combination therapeutic strategies.

MicroRNA dysregulation and multi-targeted therapy for cancer treatment

We established that loss of miR-15a/16-1 genes on chromosome 13q14 is the most common alteration in Chronic Lymphocytic Leukemia (CLL) and that miR-15/16 are crucial negative regulator of BCL-2, an antiapoptotic gene overexpressed in most CLLs and in many other malignancies. We have also shown that miR-15/16 target ROR1, a cell surface receptor for Wnt5a which can enhance growth/survival of CLL cells. Interestingly, ROR1 is expressed by many cancers, but not by normal adult tissues. Moreover, Venetoclax, the anti-Bcl-2 drug, and Cirmtuzumab, the monoclonal antibody against ROR1, are synergistic in killing CLL cells. Since an additional miR-15/16 locus exists on chromosome 3q25 (miR-15b/16-2), we generated a knocked out mouse model to study its the role in cancer. We observed that the KO mice developed predominantly CLL. Thus, we generated a double knock out mouse model where both miR-15/16 loci were deleted. Surprisingly we observed that 77% of double KO mice developed Acute Myeloid Leukemia (AML). Based on these evidences, we anticipate that also AMLs with low miR-15/16 expression, overexpression of BCL2 and expression of ROR1, would show an excellent response to a combination therapy with Venetoclax and Cirmtuzumab, since both drugs target the same malignant cells that have lost miR-15/16.

Potential Anticancer Properties and Mechanisms of Action of Formononetin

Nature, a vast reservoir of pharmacologically active molecules, has been most promising source of drug leads for the cure of various pathological conditions. Formononetin is one of the bioactive isoflavones isolated from different plants mainly from Trifolium pratense, Glycine max, Sophora flavescens, Pycnanthus angolensis, and Astragalus membranaceus. Formononetin has been well-documented for its anti-inflammatory, anticancer, and antioxidant properties. Recently anticancer activity of formononetin is widely studied. This review aims to highlight the pharmacological potential of formononetin, thus providing an insight of its status in cancer therapeutics. Formononetin fights progression of cancer via inducing apoptosis, arresting cell cycle, and halting metastasis via targeting various pathways which are generally modulated in several cancers. Although reported data acclaims various biological properties of formononetin, further experimentation on mechanism of its action, medicinal chemistry studies, and preclinical investigations are surely needed to figure out full array of its pharmacological and biological potential.

Pseudolaric acid B inhibits PAX2 expression through Wnt signaling and induces BAX expression, therefore promoting apoptosis in HeLa cervical cancer cells

Objectives

Pseudolaric acid B (PAB) has been shown to inhibit the growth of various tumor cells, but the molecular details of its function are still unknown. This study investigated the molecular mechanisms by which PAB induces apoptosis in HeLa cells.

Methods

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were performed to investigate the effect of PAB treatment in various cervical cancer cell lines. Annexin V/propidium iodide staining combined with flow cytometry and Hoechst 33258 staining were used to assess PAB-induced apoptosis. Additionally, we performed bioinformatics analyses and identified a paired box 2 (PAX2) binding site on the BAX promoter. We then validated the binding using luciferase and chromatin immunoprecipitation assays. Finally, western blotting assays were used to investigate PAB effect on the Wnt signaling and the involved signaling molecules.

Results

PAB promotes apoptosis and downregulates PAX2 expression in HeLa cells in a time- and concentration-dependent manner. PAX2 binds to the promoter of BAX and inhibits its expression; therefore, PAX2 inhibition is associated with increased levels of BAX, which induces apoptosis of HeLa cells via the mitochondrial pathway. Additionally, PAB inhibits classical Wnt signaling.

Conclusion

PAB effectively inhibits Wnt signaling and PAX2 expression, and increases BAX levels, which induce apoptosis in HeLa cells. Therefore, PAB is a promising natural molecule for the treatment of cervical cancer.

Apoptosis regulation in adrenocortical carcinoma

Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.

Curcuma raktakanda Induces Apoptosis and Suppresses Migration in Cancer Cells: Role of Reactive Oxygen Species

Although over 100 species of Curcuma are reported, only Curcuma longa is extensively studied. Curcuma raktakanda, a poorly studied species, is most commonly distributed in the Kerala state of India. For the first time, we examined the efficacy of different fractions (acetone, hexane, and ethyl acetate) of C. raktakanda against glioma, cervical, and breast cancer cell lines. As determined by mitochondrial reductase activity assay, the viability of cancer cells was decreased in a concentration-dependent manner by the three fractions. The half maximal inhibitory concentration (IC-50) values after the treatment of C-6 glioma cells for 48 h was found to be 32.97 µg/mL (acetone extract), 40.63 µg/mL (hexane extract), and 51.65 µg/mL (ethyl acetate extract). Of the three fractions, the acetone fraction was more effective. The long-term colony formation of cancer cells was significantly suppressed by the acetone fraction. Analyses using DAPI (4',6-diamidino-2-phenylindole) staining, AO/PI (acridine orange/propidium iodide) staining, DNA laddering, and sub-G1 population revealed that the acetone extract induced apoptosis in glioma cells. The extract induced reactive oxygen species generation and suppressed the expression of cell survival proteins. The migration of cancer cells was also suppressed by the acetone extract. The gas chromatography-mass spectrometry (GC-MS) analysis indicated that tetracontane, dotriacontane, hexatriacontane, pentacosane, hexacosane, and eicosane are the major components in the acetone extract. Collectively, the extract from C. raktakanda exhibited anti-carcinogenic activities in cancer cells. We are exploring whether the phytoconstituents, individually, or collectively contribute to the anti-cancer activities of C. raktakanda.

Emodin inhibits colon cancer by altering BCL-2 family proteins and cell survival pathways

Background

Currently offered therapeutics to treat colon cancer (CoCa) are toxic when given at maximum tolerated dose to achieve optimal clinical response. Hence, less toxic therapeutic intervention is needed to treat CoCa. In this study, we investigated the effect of a natural agent, Emodin, on CoCa.

Methods

Cell viability (MTT) assay was used to determine the effect of Emodin on human CoCa and colon epithelial cells. Flow cytometric analysis was used to determine Emodin induced cell death. Antibody microarray and western blot analyses were used to determine Emodin induced molecular changes involved in cell death. Change in mitochondrial membrane potential in response to Emodin was determined by flow cytometric analysis. Expression and localization of Bcl-2 family proteins were assessed by western blot analysis.

Results

Emodin decreased viability of CoCa cells and induced apoptosis in a time and dose-dependent manner compared to vehicle-treated control without significantly impacting normal colon epithelial cells. Emodin activated caspases, modulated Bcl-2 family of proteins and reduced mitochondrial membrane potential to induce CoCa cell death. Further, changes in Bcl-2 family protein expression and localization correlated with loss in mitochondrial membrane potential. Signaling (MAPK/JNK, PI3K/AKT, NF-κβ and STAT) pathways associated with cell growth, differentiation, and Bcl-2 family expression or function were negatively regulated by Emodin.

Conclusions

Ability of Emodin to impact molecular pathways involved in cell survival and apoptosis highlight the potential of this agent as a new and less toxic alternative for CoCa treatment.

Establishment and Characterization of 5-Fluorouracil-Resistant Human Colorectal Cancer Stem-Like Cells: Tumor Dynamics under Selection Pressure

5-Fluorouracil (5-FU) remains the gold standard of first-line treatment for colorectal cancer (CRC). Although it may initially debulk the tumor mass, relapses frequently occur, indicating the existence of cancer cells that are therapy-resistant and are capable of refueling tumor growth. To identify mechanisms of drug resistance, CRC stem-like cells were subjected to long-term 5-FU selection using either intermittent treatment regimen with the IC50 drug dose or continuous treatment regimen with escalating drug doses. Parental cancer cells were cultivated in parallel. Real-time PCR arrays and bioinformatic tools were used to investigate gene expression changes. We found the first method selected for cancer cells with more aggressive features. We therefore transplanted these cancer cells or parental cells in mice, and again, found that not only did the 5-FU-selected cancer cells generate more aggressive tumors with respect to their parental counterpart, but they also showed a different gene expression pattern as compared to what we had observed in vitro, with ID1 the top upregulated gene. We propose ID1 as a stemness marker pervasively expressed in secondary lesions emerging after completion of chemotherapy.

Functional role of RBM10 in lung adenocarcinoma proliferation

Lung cancer is one of the most common causes of morbidity and mortality among malignant tumors worldwide. The poor prognosis of patients with lung adenocarcinomas is primarily due to its strong ability to invade and metastasize. Recent research has indicated that RNA‑binding protein 10 (RBM10) is mutated in lung adenocarcinoma, and is closely associated with tumor proliferation and apoptosis; however, the precise role of RBM10 in lung adenocarcinoma remains unclear. Our preliminary experiments (unpublished data) revealed that RBM10 expression was upregulated in lung adenocarcinoma cell lines and tissues. In this study, we first detected the protein expression level of RBM10 in lung adenocarcinoma cells and tissues, and we then examined the effects of RBM10 overexpression and downregulation (via small interfering RNA) on the proliferation and apoptosis of stable lung adenocarcinoma cells, along with its possible mechanisms of action. We also used clinical samples of lung adenocarcinomas to verify our results. We found that RBM10 protein was overexpressed in lung adenocarcinoma cells and tissues, and it reduced p53 expression (as detected by immunofluorescence assay and western blot analysis) in A549 cells and inhibited apoptosis (as shown by flow cytometric assay). RBM10 also promoted cell growth and proliferation in vitro and increased cell migration in a cell wound scratch assay. Furthermore, we found that RBM10 activated key proliferative signaling pathways [such as the epidermal growth factor receptor (EGFR), mitogen‑activated protein kinase (MAPK) and phosphoinositide 3‑kinase (PI3K)‑AKT pathways] and inhibited apoptotic pathways. In addition, we demonstrated that a high expression of RBM10 protein in patient tissue samples was associated with a shorter overall survival time and a poor prognosis. On the whole, the findings of this study indicate that RBM10 may function as an oncogene in lung cancer, and may thus prove to be a novel therapeutic target for the prophylaxis and treatment of lung adenocarcinomas.

Staurosporine induces apoptosis in pancreatic carcinoma cells PaTu 8988t and Panc-1 via the intrinsic signaling pathway

BACKGROUND

Cancer, one of the leading causes of death worldwide, develops when the normal balance between mitosis and apoptosis is disrupted. The subsequently increased proliferation rate or decreased apoptosis rate of cells leads to uncontrolled cellular growth. Thus, the current aim of cancer research is to increase the apoptosis rate in tumor cells-while limiting the concurrent death of healthy cells-and to induce controlled apoptosis in abnormal cells. Staurosporine is a very potent inducer of apoptosis because it inhibits many different kinases. So far, many different kinase pathways of staurosporine-induced apoptosis have been discussed for various tumor entities.

AIMS

To identify the effect of staurosporine in pancreatic and colorectal carcinoma cells and its apoptosis-inducing signaling pathway.

METHODS

The apoptosis rate in pancreatic and colorectal carcinoma cells was analyzed by annexin V staining after staurosporine administration. Staurosporine stimulation and its effects on the expression of Bcl2, BAX, Bad, caspase-8, and caspase-9 were investigated with immunoblot.

RESULTS

Staurosporine significantly increased apoptosis in pancreatic carcinoma cells. Western blot analysis showed activation of caspase-9 in PaTu 8988t and Panc-1 cells with 1 µM staurosporine. In addition, expression of Bcl2 and Bad was decreased in PaTu 8988t cells. In colorectal carcinoma cells SW 480, staurosporine stimulation did not induce apoptosis.

CONCLUSION

Modern therapeutic strategies for tumor diseases target the efficient modulation of specific signaling and transcription pathways. In this respect, the therapeutic potential of protein kinase inhibitors has been repeatedly discussed. Our study showed that staurosporine induces apoptosis in pancreatic carcinoma cells via the intrinsic signaling pathway. Thus, staurosporine is a suitable positive control for in vitro apoptosis tests for the pancreatic cancer cell lines PaTu 8988t and Panc-1. Further clinical studies should analyze the impact of this finding on cancer treatment.

Clausenidin Induces Caspase 8-Dependent Apoptosis and Suppresses Production of VEGF in Liver Cancer Cells

Clausena excavata Burm f. is used by traditional healers to treat cancer patients in South East Asia. The use of the plant and its compounds is based on Asian folklore with little or no scientific evidence supporting the therapeutic efficacy The current study aimed to determine the effect of pure clausenidin isolated from C. excavata on caspase-8-induced cell death as well as angiogenesis in the HepG2 hepatocellular carcinoma cell line. Caspase-8 and extrinsic death receptor protein expression was determined using spectrophotometry and protein profile arrays, respectively. Ultrastructural analysis of clausenidin-treated cells was conducted using transmission electron microscopy. In addition, anti-angiogenic effects of clausenidin were investigated by Western blot analysis. Clausenidin significantly (p<0.05) increased the activity of caspase-8 and expression of protein components of the death inducing signaling complex (DISC) in HepG2 cells. Ultrastructural analysis of the clausenidin-treated HepG2 cells revealed morphological abnormalities typical of apoptosis. Furthermore, clausenidin significantly (p<0.05) decreased the expression of vascular endothelial growth factor (VEGF). Therefore, clausenidin is a potential anti-angiogenic agent which may induce apoptosis of hepatocellular carcinoma cells.

Mitochondrial VDAC1-based peptides: Attacking oncogenic properties in glioblastoma

Glioblastoma multiforme (GBM), a primary brain malignancy characterized by high morbidity, invasiveness, proliferation, relapse and mortality, is resistant to chemo- and radiotherapies and lacks effective treatment. GBM tumors undergo metabolic reprograming and develop anti-apoptotic defenses. We targeted GBM with a peptide derived from the mitochondrial protein voltage-dependent anion channel 1 (VDAC1), a key component of cell energy, metabolism and apoptosis regulation. VDAC1-based cell-penetrating peptides perturbed cell energy and metabolic homeostasis and induced apoptosis in several GBM and GBM-derived stem cell lines. We found that the peptides simultaneously attacked several oncogenic properties of human U-87MG cells introduced into sub-cutaneous xenograft mouse model, inhibiting tumor growth, invasion, and cellular metabolism, stemness and inducing apoptosis. Peptide-treated tumors showed decreased expression of all tested metabolism-related enzymes and transporters, and elevated levels of apoptotic proteins, such as p53, cytochrome c and caspases. Retro-Tf-D-LP4, containing the human transferrin receptor (TfR)-recognition sequence, crossed the blood-brain barrier (BBB) via the TfR that is highly expressed in the BBB to strongly inhibit tumor growth in an intracranial xenograft mouse model. In summary, the VDAC1-based peptides tested here offer a potentially affordable and innovative new conceptual therapeutic paradigm that might overcome GBM stemness and invasiveness and reduce relapse rates.