Paclitaxel sensitivity of breast cancer cells with constitutively active NF-kappaB is enhanced by IkappaBalpha super-repressor and parthenolide

In Vivo and Clinical Studies of Natural Products Targeting the Hallmarks of Cancer

Despite more than 200 approved anticancer agents, cancer remains a leading cause of death worldwide due to disease complexity, tumour heterogeneity, drug toxicity, and the emergence of drug resistance. Accordingly, the development of chemotherapeutic agents with higher efficacy, a better safety profile, and the capability of bypassing drug resistance would be a cornerstone in cancer therapy. Natural products have played a pivotal role in the field of drug discovery, especially for the pharmacotherapy of cancer, infectious, and chronic diseases. Owing to their distinctive structures and multiple mechanistic activities, natural products and their derivatives have been utilized for decades in cancer treatment protocols. In this review, we delve into the potential of natural products as anticancer agents by targeting cancer's hallmarks, including sustained proliferative signalling, evading growth suppression, resisting apoptosis and cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis. We highlight the molecular mechanisms of some natural products, in vivo studies, and promising clinical trials. This review emphasizes the significance of natural products in fighting cancer and the need for further studies to uncover their fully therapeutic potential.

WITHDRAWN: LonP1 Drives Proneural Mesenchymal Transition in IDH1-R132H Diffuse Glioma

The authors have withdrawn their manuscript owing to massive revision and data validation. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

WITHDRAWN: Dual targeting of mitochondrial Lon peptidase 1 and chymotrypsin-like protease by small molecule BT317, as potential therapeutics in malignant astrocytomas

The authors have withdrawn their manuscript owing to massive revision and data validation. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.

A poly-histidine motif of HOXA1 is involved in regulatory interactions with cysteine-rich proteins

Homopolymeric amino acid repeats are found in about 24 % of human proteins and are over-represented in transcriptions factors and kinases. Although relatively rare, homopolymeric histidine repeats (polyH) are more significantly found in proteins involved in the regulation of embryonic development. To gain a better understanding of the role of polyH in these proteins, we used a bioinformatic approach to search for shared features in the interactomes of polyH-containing proteins in human. Our analysis revealed that polyH protein interactomes are enriched in cysteine-rich proteins and in proteins containing (a) cysteine repeat(s). Focusing on HOXA1, a HOX transcription factor displaying one long polyH motif, we identified that the polyH motif is required for the HOXA1 interaction with such cysteine-rich proteins. We observed a correlation between the length of the polyH repeat and the strength of the HOXA1 interaction with one Cys-rich protein, MDFI. We also found that metal ion chelators disrupt the HOXA1-MDFI interaction supporting that such metal ions are required for the interaction. Furthermore, we identified three polyH interactors which down-regulate the transcriptional activity of HOXA1. Taken together, our data point towards the involvement of polyH and cysteines in regulatory interactions between proteins, notably transcription factors like HOXA1.

Parthenolide As a Therapeutic for Disseminated Canine Neoplasms

This study provides a unique translational research opportunity to help both humans and dogs diagnosed with diseases that carry dismal prognoses in both species: histiocytic sarcoma (HS), hemangiosarcoma (HSA), and disseminated mastocytosis/mast cell tumor (MCT). Although exceedingly rare in humans, these so called "orphan diseases" are relatively more common in dogs. For these and other more commonplace cancers like lymphoma (Lym), dogs are an excellent translational model for human disease due to remarkably similar disease biology. In this study, assays were performed to assess the therapeutic potential of parthenolide (PTL), a known canonical nuclear factor kappa B (NF-κB) signaling inhibitor with additional mechanisms of antineoplastic activity, including alteration of cellular reduction-oxidation balance. Canine cell lines and primary cells are sensitive to PTL and undergo dose-dependent apoptosis after exposure to drug. PTL exposure also leads to glutathione depletion, reactive oxygen species generation, and NF-κB inhibition in canine cells. Standard-of-care therapeutics broadly synergize with PTL. In two canine HS cell lines, expression of NF-κB pathway signaling partners is downregulated with PTL therapy. Preliminary data suggest that PTL inhibits NF-κB activity of cells and extends survival time in a mouse model of disseminated canine HS. These data support further investigation of compounds that can antagonize canonical NF-κB pathway signaling in these cancers and pave the way for clinical trials of PTL in affected dogs. As dogs are an excellent natural disease model for these cancers, these data will ultimately improve our understanding of their human disease counterparts and hopefully improve care for both species. SIGNIFICANCE STATEMENT: Disseminated neoplasms in human and canine cancers are challenging to treat, and novel therapeutic approaches are needed to improve outcomes. Parthenolide is a promising treatment for histiocytic sarcoma, hemangiosarcoma, and mast cell neoplasia.

Sunitinib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers

Currently, renal cell carcinoma (RCC) is the most prevalent type of kidney cancer. Targeted therapy has replaced radiation therapy and chemotherapy as the main treatment option for RCC due to the lack of significant efficacy with these conventional therapeutic regimens. Sunitinib, a drug used to treat gastrointestinal tumors and renal cell carcinoma, inhibits the tyrosine kinase activity of a number of receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), c-Kit, rearranged during transfection (RET) and fms-related receptor tyrosine kinase 3 (Flt3). Although sunitinib has been shown to be efficacious in the treatment of patients with advanced RCC, a significant number of patients have primary resistance to sunitinib or acquired drug resistance within the 6-15 months of therapy. Thus, in order to develop more efficacious and long-lasting treatment strategies for patients with advanced RCC, it will be crucial to ascertain how to overcome sunitinib resistance that is produced by various drug resistance mechanisms. In this review, we discuss: 1) molecular mechanisms of sunitinib resistance; 2) strategies to overcome sunitinib resistance and 3) potential predictive biomarkers of sunitinib resistance.

Proteomic and functional characterization of intra-tumor heterogeneity in human endometrial cancer

Endometrial cancer is one of the most frequently diagnosed gynecological cancers worldwide, and its prevalence has increased by more than 50% over the last two decades. Despite the understanding of the major signaling pathways driving the growth and metastasis of endometrial cancer, clinical trials targeting these signals have reported poor outcomes. The heterogeneous nature of endometrial cancer is suspected to be one of the key reasons for the failure of targeted therapies. In this study, we perform a sequential window acquisition of all theoretical fragment ion spectra (SWATH)-based comparative proteomic analysis of 63 tumor biopsies collected from 20 patients and define differences in protein signature in multiple regions of the same tumor. We develop organoids from multiple biopsies collected from the same tumor and show that organoids capture heterogeneity in endometrial cancer growth. Overall, using quantitative proteomics and patient-derived organoids, we define the heterogeneous nature of endometrial cancer within a patient’s tumor.

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Proteomic analysis of endometrial cancer intra-tumor heterogeneity

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Identification of potential biomarkers of tumor volume and invasion

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Protein signatures correlate with pre-and postmenopausal cancers

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Patient-derived organoids capture endometrial cancer heterogeneity

Mechanisms of cancer cell death induction by paclitaxel: an updated review

Chemoresistance of cancer cells is a major problem in treating cancer. Knowledge of how cancer cells may die or resist cancer drugs is critical to providing certain strategies to overcome tumour resistance to treatment. Paclitaxel is known as a chemotherapy drug that can suppress the proliferation of cancer cells by inducing cell cycle arrest and induction of mitotic catastrophe. However, today, it is well known that paclitaxel can induce multiple kinds of cell death in cancers. Besides the induction of mitotic catastrophe that occurs during mitosis, paclitaxel has been shown to induce the expression of several pro-apoptosis mediators. It also can modulate the activity of anti-apoptosis mediators. However, certain cell-killing mechanisms such as senescence and autophagy can increase resistance to paclitaxel. This review focuses on the mechanisms of cell death, including apoptosis, mitotic catastrophe, senescence, autophagic cell death, pyroptosis, etc., following paclitaxel treatment. In addition, mechanisms of resistance to cell death due to exposure to paclitaxel and the use of combinations to overcome drug resistance will be discussed.

Targeting cancer signaling pathways by natural products: Exploring promising anti-cancer agents

Cancer is one of the leading causes of death and significantly burdens the healthcare system. Due to its prevalence, there is undoubtedly an unmet need to discover novel anticancer drugs. The use of natural products as anticancer agents is an acceptable therapeutic approach due to accessibility, applicability, and reduced cytotoxicity. Natural products have been an incomparable source of anticancer drugs in the modern era of drug discovery. Along with their derivatives and analogs, natural products play a major role in cancer treatment by modulating the cancer microenvironment and different signaling pathways. These compounds are effective against several signaling pathways, mainly cell death pathways (apoptosis and autophagy) and embryonic developmental pathways (Notch pathway, Wnt pathway, and Hedgehog pathway). The historical record of natural products is strong, but there is a need to investigate the current role of natural products in the discovery and development of cancer drugs and determine the possibility of natural products being an important source of future therapeutic agents. Many target-specific anticancer drugs failed to provide successful results, which accounts for a need to investigate natural products with multi-target characteristics to achieve better outcomes. The potential of natural products to be promising novel compounds for cancer treatment makes them an important area of research. This review explores the significance of natural products in inhibiting the various signaling pathways that serve as drivers of carcinogenesis and thus pave the way for developing and discovering anticancer drugs.

N6-methyladenosine-modified TRAF1 promotes sunitinib resistance by regulating apoptosis and angiogenesis in a METTL14-dependent manner in renal cell carcinoma

Background

Sunitinib resistance can be classified into primary and secondary resistance. While accumulating research has indicated several underlying factors contributing to sunitinib resistance, the precise mechanisms in renal cell carcinoma are still unclear.

Methods

RNA sequencing and m6A sequencing were used to screen for functional genes involved in sunitinib resistance. In vitro and in vivo experiments were carried out and patient samples and clinical information were obtained for clinical analysis.

Results

We identified a tumor necrosis factor receptor-associated factor, TRAF1, that was significantly increased in sunitinib-resistant cells, resistant cell-derived xenograft (CDX-R) models and clinical patients with sunitinib resistance. Silencing TRAF1 increased sunitinib-induced apoptotic and antiangiogenic effects. Mechanistically, the upregulated level of TRAF1 in sunitinib-resistant cells was derived from increased TRAF1 RNA stability, which was caused by an increased level of N6-methyladenosine (m6A) in a METTL14-dependent manner. Moreover, in vivo adeno-associated virus 9 (AAV9) -mediated transduction of TRAF1 suppressed the sunitinib-induced apoptotic and antiangiogenic effects in the CDX models, whereas knockdown of TRAF1 effectively resensitized the sunitinib-resistant CDXs to sunitinib treatment.

Conclusions

Overexpression of TRAF1 promotes sunitinib resistance by modulating apoptotic and angiogenic pathways in a METTL14-dependent manner. Targeting TRAF1 and its pathways may be a novel pharmaceutical intervention for sunitinib-treated patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01549-1.

Nanoparticle-based drug delivery systems in cancer: A focus on inflammatory pathways

It has become necessary to accept the clinical reality of therapeutic agents targeting the cancer-associated immune system. In recent decades, several investigations have highlighted the role of inflammation in cancer development. It has now been recognized that inflammatory cells secrete mediators, including enzymes, chemokines, and cytokines. These secreted substances produce an inflammatory microenvironment that is critically involved in cancer growth. Inflammation may enhance genomic instability leading to DNA damage, activation of oncogenes, or compromised tumor suppressor activity, all of which may promote various phases of carcinogenesis. Conventional cancer treatment includes surgery, radiation, and chemotherapy. However, treatment failure occurs because current strategies are unable to achieve complete local control due to metastasis. Nanoparticles (NPs) are a broad spectrum of drug carriers typically below the size of 100 nm, targeting tumor sites while reducing off-target consequences. More importantly, NPs can stimulate innate and adaptive immune systems in the tumor microenvironment (TME); hence, they induce a cancer-fighting immune response. Strikingly, targeting cancer cells with NPs helps eliminate drug resistance and tumor recurrence, as well as prevents inflammation. Throughout this review, we provide recent data on the role of inflammation in cancer and explore nano-therapeutic initiatives to target significant mediators, for example, nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α), and interleukins (ILs) associated with cancer-related inflammation, to escort the immunomodulators to cancer cells and associated systemic compartments. We also highlight the necessity of better identifying inflammatory pathways in cancer pathophysiology to develop effective treatment plans.

Psoralen-loaded polymeric lipid nanoparticles combined with paclitaxel for the treatment of triple-negative breast cancer

Background: Chemotherapeutic drugs are associated with toxic effects. Metastasis is the leading cause of death in breast cancer patients. Aim: To evaluate the antitumor effect of paclitaxel (PTX) combined with psoralen-loaded polymeric lipid nanoparticles (PSO-PLNs) in triple-negative breast cancer. Methods: After treatment of samples, cell viability, apoptosis, migration, invasion, expression of proteins in the IRAK1/NF-κB/FAK signal pathway, biodistribution and pathological characteristics were detected. Results: Compared with the control group, the PTX + PSO-PLNs group showed increased apoptosis and reduced migration, invasion and expression of phosphorylated IRAK1 and NF-κB, with significant inhibition of tumor growth and lung metastases and no obvious toxicity. Conclusion: Combined administration of PTX and PSO-PLNs exerted a synergistic effect and significantly inhibited the growth and metastasis of triple-negative breast cancer.

Ganglioside GD2: a novel therapeutic target in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by lack of hormone receptor expression and is known for high rates of recurrence, distant metastases, and poor clinical outcomes. TNBC cells lack targetable receptors; hence, there is an urgent need for targetable markers for the disease. Breast cancer stem-like cells (BCSCs) are a fraction of cells in primary tumors that are associated with tumorigenesis, metastasis, and resistance to chemotherapy. Targeting BCSCs is thus an effective strategy for preventing cancer metastatic spread and sensitizing tumors to chemotherapy. The CD44^hi CD24^lo phenotype is a well-established phenotype for identification of BCSCs, but CD44 and CD24 are not targetable markers owing to their expression in normal tissues. The ganglioside GD2 has been shown to be upregulated in primary TNBC tumors compared with normal breast tissue and has been shown to identify BCSCs. In this review, we discuss GD2 as a BCSC- and tumor-specific marker in TNBC; epithelial-to-mesenchymal transition and the signaling pathways that are upstream and downstream of GD2 and the role of these pathways in tumorigenesis and metastasis in TNBC; direct and indirect approaches for targeting GD2; and ongoing clinical trials and treatments directed against GD2 as well as future directions for these strategies.

Visualization of the cancer cell cycle by tissue-clearing technology using the Fucci reporter system

Tissue-clearing technology is an emerging imaging technique currently utilized not only in neuroscience research but also in cancer research. In our previous reports, tissue-clearing methods were used for the detection of metastatic tumors. Here, we showed that the cell cycles of primary and metastatic tumors were visualized by tissue-clearing methods using a reporter system. First, we established cancer cell lines stably expressing fluorescent ubiquitination-based cell cycle indicator (Fucci) reporter with widely used cancer cell lines A549 and 4T1. Fluorescence patterns of the Fucci reporter were investigated in various tumor inoculation models in mice. Interestingly, fluorescence patterns of the Fucci reporter of tumor colonies were different between various organs, and even among colonies in the same organs. The effects of antitumor drugs were also evaluated using these Fucci reporter cells. Of the three antitumor drugs studied, 5-fluorouracil treatment on 4T1-Fucci cells resulted in characteristic fluorescent patterns by the induction of G2 /M arrest both in vitro and in vivo. Thus, the combination of a tissue-clearing method with the Fucci reporter is useful for analyzing the mechanisms of cancer metastasis and drug resistance.

Resistance to Intervention: Paclitaxel in Breast Cancer

Breast cancer stands as the most prevalent cancer in women globally, and contributes to the highest percentage of mortality due to cancer-related deaths in women. Paclitaxel (PTX) is heavily relied on as a frontline chemotherapy drug in breast cancer treatment, especially in advanced metastatic cancer. Generation of resistance to PTX often derails clinical management and adversely affects patient outcomes. Understanding the molecular mechanism of PTX resistance is necessary to device methods to aid in overcoming the resistance. Recent studies exploring the mechanism of development of PTX resistance have led to unveiling of a range novel therapeutic targets. PTX resistance pathways that involve major regulatory proteins/RNAs like RNF8/Twist/ROR1, TLR, ErbB3/ErbB2, BRCA1- IRIS, MENA, LIN9, MiRNA, FoxM1 and IRAK1 have expanded the complexity of resistance mechanisms, and brought newer insights into the development of drug targets. These resistance-related targets can be dealt with synthetic/natural therapeutics in combination with PTX. The present review encompasses the recent understanding of PTX resistance mechanisms in breast cancer and possible therapeutic combinations to overcome resistance.

Design, synthesis and in vivo anticancer activity of novel parthenolide and micheliolide derivatives as NF-κB and STAT3 inhibitors

Parthenolide and micheliolide have attracted great attention in anticancer research due to their unique activities. In this study, thirteen parthenolide derivatives and twenty-three micheliolide derivatives were synthesized. Most synthesized compounds showed higher cytotoxicity than parthenolide or micheliolide. The in vivo anticancer activity of several representative compounds was evaluated in mice. One micheliolide derivative, 9-oxomicheliolide (43), showed promising in vivo antitumor activity compared with clinical drugs cyclophosphamide or temozolomide. Compound 43 was particularly effective against glioblastoma, with its tumor inhibition rate in mice comparable to the drug temozolomide. The discovery of compound 43 also demonstrates the feasibility of developing anticancer micheliolide derivatives by modification at C-9 position. Anticancer mechanism studies revealed that 9-oxomicheliolide exhibited inhibition effect against NF-κB and STAT3 signaling pathways, as well as induction effects of cell apoptosis. It is postulated that 9-oxomicheliolide is likely to be a modulator of the immune system, which regulates the anticancer immune responses.

Multifunctional nanoplatforms co-delivering combinatorial dual-drug for eliminating cancer multidrug resistance

Clinically, the primary cause of chemotherapy failure belongs to the occurrence of cancer multidrug resistance (MDR), which directly leads to the recurrence and metastasis of cancer along with high mortality. More and more attention has been paid to multifunctional nanoplatform-based dual-therapeutic combination to eliminate resistant cancers. In addition to helping both cargoes improve hydrophobicity and pharmacokinetic properties, increase bioavailability, release on demand and enhance therapeutic efficacy with low toxic effects, these smart co-delivery nanocarriers can even overcome drug resistance. Here, this review will not only present different types of co-delivery nanocarriers, but also summarize targeted and stimuli-responsive combination nanomedicines. Furthermore, we will focus on the recent progress in the co-delivery of dual-drug using such intelligent nanocarriers for surmounting cancer MDR. Whereas it remains to be seriously considered that there are some knotty issues in the fight against MDR of cancers via using co-delivery nanoplatforms, including limited intratumoral retention, the possible changes of combinatorial ratio under complex biological environments, drug release sequence from the nanocarriers, and subsequent free-drug resistance after detachment from the nanocarriers. It is hoped that, with the advantage of continuously developing nanomaterials, two personalized therapeutic agents in combination can be better exploited to achieve the goal of cooperatively combating cancer MDR, thus advancing the time to clinical transformation.

Therapeutic strategies to overcome taxane resistance in cancer

One of the primary causes of attenuated or loss of efficacy of cancer chemotherapy is the emergence of multidrug resistance (MDR). Numerous studies have been published regarding potential approaches to reverse resistance to taxanes, including paclitaxel (PTX) and docetaxel, which represent one of the most important classes of anticancer drugs. Since 1984, following the FDA approval of paclitaxel for the treatment of advanced ovarian carcinoma, taxanes have been extensively used as drugs that target tumor microtubules. Taxanes, have been shown to affect an array of oncogenic signaling pathways and have potent cytotoxic efficacy. However, the clinical success of these drugs has been restricted by the emergence of cancer cell resistance, primarily caused by the overexpression of MDR efflux transporters or by microtubule alterations. In vitro and in vivo studies indicate that the mechanisms underlying the resistance to PTX and docetaxel are primarily due to alterations in α-tubulin and β-tubulin. Moreover, resistance to PTX and docetaxel results from: 1) alterations in microtubule-protein interactions, including microtubule-associated protein 4, stathmin, centriole, cilia, spindle-associated protein, and kinesins; 2) alterations in the expression and activity of multidrug efflux transporters of the ABC superfamily including P-glycoprotein (P-gp/ABCB1); 3) overexpression of anti-apoptotic proteins or inhibition of apoptotic proteins and tumor-suppressor proteins, as well as 4) modulation of signal transduction pathways associated with the activity of several cytokines, chemokines and transcription factors. In this review, we discuss the abovementioned molecular mechanisms and their role in mediating cancer chemoresistance to PTX and docetaxel. We provide a detailed analysis of both in vitro and in vivo experimental data and describe the application of these findings to therapeutic practice. The current review also discusses the efficacy of different pharmacological modulations to achieve reversal of PTX resistance. The therapeutic roles of several novel compounds, as well as herbal formulations, are also discussed. Among them, many structural derivatives had efficacy against the MDR phenotype by either suppressing MDR or increasing the cytotoxic efficacy compared to the parental drugs, or both. Natural products functioning as MDR chemosensitizers offer novel treatment strategies in patients with chemoresistant cancers by attenuating MDR and increasing chemotherapy efficacy. We broadly discuss the roles of inhibitors of P-gp and other efflux pumps, in the reversal of PTX and docetaxel resistance in cancer cells and the significance of using a nanomedicine delivery system in this context. Thus, a better understanding of the molecular mechanisms mediating the reversal of drug resistance, combined with drug efficacy and the application of target-based inhibition or specific drug delivery, could signal a new era in modern medicine that would limit the pathological consequences of MDR in cancer patients.

Phase I dose-escalation, safety, and CNS pharmacokinetic study of dexanabinol in patients with brain cancer

Background

Dexanabinol is a synthetic analogue of tetrahydrocannabinol identified as a potential anti-cancer therapeutic by e-Therapeutics PLC. Dexanabinol was selected for further investigation based on its preclinical tumoricidal activity. This phase I dose-escalation trial examined the safety, drug penetration into the central nervous system (CNS), preliminary antitumor activity, and recommended phase II dose.

Methods

Dexanabinol formulated in cremophor/ethanol was administered once weekly via 3-hour intravenous infusion to patients with brain cancer.

Results

A total of 26 patients were dosed once weekly at 2, 4, 8, 16, 24, 28, and 36 mg/kg. Two patients at 36 mg/kg were nonevaluable for dose level confirmation, having withdrawn early for reasons unrelated to study treatment. A recommended phase II dose of dexanabinol was established at 28 mg/kg due to related, reversible adverse events at higher dose levels that required medications for symptomatic relief. The most common drug-related toxicities were the depressed level of consciousness and lightheadedness, diarrhea, itching, fatigue, chest discomfort, and tingling in the mouth. Systemic exposure to dexanabinol (AUC_0-t and C _max) increased from 2 to 36 mg/kg, with dose nonproportionality apparent at the highest dose; dexanabinol was present in appreciable levels in the cerebrospinal fluid (CSF), which implies the possibility of exposure of intracranial tumors to drug. Five of 24 efficacy-evaluable patients (21%) experienced stable disease with a median duration of 2 cycles (28-day cycle) as the best response.

Conclusions

Dexanabinol administered weekly by intravenous infusion was safe and well-tolerated up to 28 mg/kg in brain cancer patients, but has limited antitumor activity in patients with brain cancer.

SWATH-MS Based Proteomic Profiling of Prostate Cancer Cells Reveals Adaptive Molecular Mechanisms in Response to Anti-Androgen Therapy

Prostate cancer (PCa) is the second most common cancer affecting men worldwide. PCa shows a broad-spectrum heterogeneity in its biological and clinical behavior. Although androgen targeted therapy (ATT) has been the mainstay therapy for advanced PCa, it inevitably leads to treatment resistance and progression to castration resistant PCa (CRPC). Thus, greater understanding of the molecular basis of treatment resistance and CRPC progression is needed to improve treatments for this lethal phenotype. The current study interrogated both proteomics and transcriptomic alterations stimulated in AR antagonist/anti-androgen (Bicalutamide and Enzalutamide) treated androgen-dependent cell model (LNCaP) in comparison with androgen-independent/castration-resistant cell model (C4-2B). The analysis highlighted the activation of MYC and PSF/SFPQ oncogenic upstream regulators in response to the anti-androgen treatment. Moreover, the study revealed anti-androgen induced genes/proteins related to transcription/translation regulation, energy metabolism, cell communication and signaling cascades promoting tumor growth and proliferation. In addition, these molecules were found dysregulated in PCa clinical proteomic and transcriptomic datasets, suggesting their potential involvement in PCa progression. In conclusion, our study provides key molecular signatures and associated pathways that might contribute to CRPC progression despite treatment with anti-androgens. Such molecular signatures could be potential therapeutic targets to improve the efficacy of existing therapies and/or predictive/prognostic value in CRPC for treatment response.

Functional Genomics Approaches to Elucidate Vulnerabilities of Intrinsic and Acquired Chemotherapy Resistance

Drug resistance is a commonly unavoidable consequence of cancer treatment that results in therapy failure and disease relapse. Intrinsic (pre-existing) or acquired resistance mechanisms can be drug-specific or be applicable to multiple drugs, resulting in multidrug resistance. The presence of drug resistance is, however, tightly coupled to changes in cellular homeostasis, which can lead to resistance-coupled vulnerabilities. Unbiased gene perturbations through RNAi and CRISPR technologies are invaluable tools to establish genotype-to-phenotype relationships at the genome scale. Moreover, their application to cancer cell lines can uncover new vulnerabilities that are associated with resistance mechanisms. Here, we discuss targeted and unbiased RNAi and CRISPR efforts in the discovery of drug resistance mechanisms by focusing on first-in-line chemotherapy and their enforced vulnerabilities, and we present a view forward on which measures should be taken to accelerate their clinical translation.

HOX genes and the NF-κB pathway: A convergence of developmental biology, inflammation and cancer biology

The roles of HOX transcription factors as oncogenes and tumor suppressor genes, and the NF-KB pathway in chronic inflammation, both leading to cancer are well-established. HOX transcription factors are members of an evolutionarily conserved family of proteins required for anteroposterior body axis patterning during embryonic development, and are often dysregulated in cancer. The NF-KB pathway aids inflammation and immunity but it is also important during embryonic development. It is frequently activated in both solid and hematological malignancies. NF-KB and HOX proteins can influence each other through mutual transcriptional regulation, protein-protein interactions, and regulation of upstream and downstream interactors. These interactions have important implications both in homeostasis and in disease. In this review, we summarize the role of HOX proteins in regulating inflammation in homeostasis and disease- with a particular emphasis on cancer. We also describe the relationship between HOX genes and the NF-KB pathway, and discuss potential therapeutic strategies.

Paclitaxel Promotes Tumor-Infiltrating Macrophages in Breast Cancer

OBJECTIVE

Breast cancer remains the most threatening triggers of cancer death in women. Drug resistance inevitably leads to the weakness of treatment for breast cancer. Macrophages, as one of the most abundant immune cells in tumor immune-infiltrating microenvironment, involves in cell survival, migration, and invasion of breast cancer.

METHODS

In this study, we compared the proportions of macrophages in patients with breast cancer with and without paclitaxel treatment, and investigated the targeted genes associated with macrophages for paclitaxel response. To explore the relationship between drug-related genes and breast cancer prognosis, survival analysis based on the drug-related genes were performed by website of Kaplan-Meier plotter with the threshold of significant P value < .05.

RESULTS

Compared to the normal samples, we revealed that paclitaxel significantly enhanced the ratio of macrophages in the tumor microenvironment. Furthermore, the expression of 3 drug-related genes (IFT46, PEX11A, and TMEM223) were significantly negatively associated with the proportions of macrophages. And it is worth to notice that PEX11A and TMEM223 were associated with better progression-free survival outcomes of patients with breast cancer. Moreover, PEX11A was associated with longer overall survival time of breast cancer.

CONCLUSION

Taken all together, all the findings support to gain a better understanding to the development of more effective therapies targeted with paclitaxel.

Parthenolide as Cooperating Agent for Anti-Cancer Treatment of Various Malignancies

Primary and acquired resistance of cancer to therapy is often associated with activation of nuclear factor kappa B (NF-κB). Parthenolide (PN) has been shown to inhibit NF-κB signaling and other pro-survival signaling pathways, induce apoptosis and reduce a subpopulation of cancer stem-like cells in several cancers. Multimodal therapies that include PN or its derivatives seem to be promising approaches enhancing sensitivity of cancer cells to therapy and diminishing development of resistance. A number of studies have demonstrated that several drugs with various targets and mechanisms of action can cooperate with PN to eliminate cancer cells or inhibit their proliferation. This review summarizes the current state of knowledge on PN activity and its potential utility as complementary therapy against different cancers.

A High-Throughput Image Cytometry Method for the Formation, Morphometric, and Viability Analysis of Drug-Treated Mammospheres

The nonadherent mammosphere assay has been commonly used to investigate cancer stem cell activities in breast cancers that have the ability to form tumorspheres and maintain tumor growth. The sphere formation step is critical, in that it enables the construction of the mammosphere models for downstream assays. The mammosphere assay has also been used to assess the effects of drug treatment on the tumorspheres formed from primary cancer cells or cell lines. Traditionally, the mammosphere formation has been evaluated by standard microscopy systems that required external software for additional analyses. However, this method can be time-consuming and low-throughput, thus impractical for high-throughput characterization of mammosphere models and screening for potential therapeutic cancer drugs. To overcome these challenges, we developed a plate-based high-throughput method to rapidly analyze mammospheres in whole wells using the Celigo Image Cytometer. The method is employed to characterize mammosphere formation and morphology for adherent and nonadherent propagation of four breast cancer cell lines (MCF7, MDA-MB-436, MDA-MB-231, and SKBR3). Next, the dose-dependent effects of four small molecule drugs (doxorubicin, paclitaxel, 8-quinolinol, and salinomycin) are characterized based on sphere formation and viability stained with calcein AM and propidium iodide. We observed growth and morphometric differences between adherent and nonadherent propagation of the four cell lines. Furthermore, drug treatments induced various effects on mammosphere formation, morphology, and viability. The proposed image cytometry method provides a useful tool suitable for high-throughput characterization and analysis of mammospheres, which can improve assay efficiency when investigating the formation capabilities and drug-induced cytotoxicity effects.

Preparation and characterization of parthenolide nanocrystals for enhancing therapeutic effects of sorafenib against advanced hepatocellular carcinoma

A novel nanocrystals delivery system of parthenolide (PTL) was designed to combined application with sorafenib (Sora) for advanced hepatocellular carcinoma (HCC) therapy, attempting to not only improve the poor aqueous solubility of PTL, but also enhance the synergistic therapeutic effects with Sora. The PTL nanocrystals (PTL-NCs) were prepared by precipitation-high-pressure homogenization method. The formed PTL-NCs with rod morphology possessed size of 126.9 ± 2.31 nm, zeta potential of -11.18 ± 0.59 mV and drug loading of 31.11 ± 1.99%. Meanwhile, PTL in PTL-NCs exhibited excellent storage stability and sustained release behavior. The combination therapy of Sora and PTL-NCs (Sora/PTL-NCs) in vitro for HepG2 cells presented superior therapeutic effects over that of individual PTL and Sora on intracellular uptake, cell proliferation inhibition and migration inhibition. Meanwhile the strongest anti-tumor effect with 81.86% inhibition rate and minimized systemic toxicity of Sora/PTL-NCs in vivo were obtained on tumor-bearing mice compared with that of PTL (48.84%) and Sora (58.83%). Thus, these findings suggested that PTL-NCs as an effective delivery system for the synergistically used with Sora to gain an optimal response against HCC, for referenced in the industrialization of nanocrystals products for intravenous administration.

A New Hybrid δ-Lactone Induces Apoptosis and Potentiates Anticancer Activity of Taxol in HL-60 Human Leukemia Cells

In the search for new drug candidates, researchers turn to natural substances isolated from plants which may be either used directly or may serve as a source for chemical modifications. An interesting strategy in the design of novel anticancer agents is based on the conjugation of two or more biologically active structural motifs into one hybrid compound. In this study, we investigated the anticancer potential of 4-benzyl-5,7-dimethoxy-4-methyl-3-methylidene-3,4-dihydro-2H-chroman-2-one (DL-247), a new hybrid molecule combining a chroman-2-one skeleton with an exo-methylidene bond conjugated with a carbonyl group, in human myeloid leukemia HL-60 cell line. The cytotoxicity of the new compound was tested using MTT assay. The effect of DL-247 on cell proliferation and apoptosis induction were studied by flow cytometry, fluorometric assay and ELISA analysis. DL-247 displayed high cytotoxic activity (IC₅₀ = 1.15 µM, after 24 h incubation), significantly inhibited cell proliferation and induced apoptosis by both, the intrinsic and extrinsic pathways. A combination of DL-247 with taxol exhibited a strong synergistic effect on DNA damage generation, apoptosis induction and inhibition of cell growth.

Derivatisation of parthenolide to address chemoresistant chronic lymphocytic leukaemia

Parthenolide is a natural product that exhibits anti-leukaemic activity, however, its clinical use is limited by its poor bioavailability. It may be extracted from feverfew and protocols for growing, extracting and derivatising it are reported. A novel parthenolide derivative with good bioavailability and pharmacological properties was identified through a screening cascade based on in vitro anti-leukaemic activity and calculated "drug-likeness" properties, in vitro and in vivo pharmacokinetics studies and hERG liability testing. In vitro studies showed the most promising derivative to have comparable anti-leukaemic activity to DMAPT, a previously described parthenolide derivative. The newly identified compound was shown to have pro-oxidant activity and in silico molecular docking studies indicate a prodrug mode of action. A synthesis scheme is presented for the production of amine 7 used in the generation of 5f.

Parthenolide Inhibits the Proliferation of MDA-T32 Papillary Thyroid Carcinoma Cells in Vitro and in Mouse Tumor Xenografts and Activates Autophagy and Apoptosis by Downregulation of the Mammalian Target of Rapamycin (mTOR)/PI3K/AKT Signaling Pathway

Background

This study aimed to examine the effects of the sesquiterpene lactone, parthenolide, on migration, autophagy, and apoptosis of MDA-T32 human papillary thyroid carcinoma cells in vitro and in mouse tumor xenografts.

Material/Methods

Cell proliferation and viability of MDA-T32 human papillary thyroid carcinoma cells were determined by MTT assay, and cell migration was studied using a transwell assay. Fluorescence microscopy using acridine orange (AO) and ethidium bromide (EB) staining evaluated apoptosis. Transmission electron microscopy was used to study the effects of parthenolide on autophagy, and Western blot examined the levels of autophagy-associated proteins, including Bax, Bcl-2, and LC3-ll. Mice (n=10) were injected with 5×10⁶ MDA-T32 cells subcutaneously into the left flank, and xenograft tumors were grown for six weeks. Control untreated mice (n=5) were compared with treated mice (n=5) given parthenolide three times per week.

Results

Parthenolide resulted in a dose-dependent reduction in viability and cell migration of MDA-T32 cells, with a half-maximal inhibitory concentration (IC₅₀) of 12 μM. AO and EB staining showed that parthenolide induced cell apoptosis and electron microscopy identified autophagosomes in MDA-T32 cells. Parthenolide induced increased expression of the autophagocytic proteins, LC3-II and beclin-1, had a dose-dependent inhibitory effect on the mTOR/PI3K/AKT cascade in MDA-T32 cells and inhibited the growth of the mouse xenograft tumors in vivo.

Conclusions

Parthenolide inhibited the growth and migration of MDA-T32 human papillary thyroid carcinoma cells in vitro and mouse tumor xenografts and activated autophagy and apoptosis by downregulation of the mTOR/PI3K/AKT signaling pathway.

STAT3 Activation in Combination with NF-KappaB Inhibition Induces Tolerogenic Dendritic Cells with High Therapeutic Potential to Attenuate Collagen-Induced Arthritis

Dendritic cells (DCs) have the ability to induce tolerance or inflammation in response to self-antigens, which makes them fundamental players in autoimmunity. In this regard, immunogenic DCs produce IL-12 and IL-23 favouring the acquisition of Th1 and Th17 inflammatory phenotypes, respectively, by autoreactive CD4⁺ T-cells, thus promoting autoimmunity. Conversely, tolerogenic DCs produce IL-10 and TGF-β, inducing the generation of CD4⁺ T-cells with suppressive activity (Treg), which promote tolerance to self-constituents. Previous studies have shown that STAT3 signalling in DCs attenuates the production of proinflammatory cytokines, whilst NF-κB activation promotes it. In this study, we aimed to generate DCs displaying strong and constitutive tolerogenic profile to be used as immunotherapy in autoimmunity. To this end, we transduced bone marrow-derived DCs with lentiviral particles codifying for a constitutively active version of STAT3 (constitutively active STAT3 (STAT3ca)) or with a constitutive repressor of NF-κB (IκBα superrepressor (IκBαSR)), and their therapeutic potential was evaluated in a mouse model of arthritis induced by collagen (CIA). Our results show that STAT3ca transduction favoured the production of the anti-inflammatory mediator IL-10, whereas IκBαSR transduction attenuated the expression of the proinflammatory cytokine IL-23 in DCs. Moreover, both STAT3ca-transduced and IκBαSR-transduced DCs separately exerted a mild but significant therapeutic effect reducing the severity of CIA development. Furthermore, when DCs were transduced with both STAT3ca and IκBαSR together, they reduced CIA manifestation significantly stronger than when transduced with only STAT3ca or IκBαSR separately. These results show STAT3 and NF-κB as two important and complementary regulators of the tolerogenic behaviour of DCs, which should be considered as molecular targets in the design of DC-based suppressive immunotherapies for the treatment of autoimmune disorders.

Large-Scale Target Identification of Herbal Medicine Using a Reverse Docking Approach

Herbal medicine has been used to countermine various diseases for centuries. However, most of the therapeutic targets underlying herbal therapy remain unclear, which largely slow down the novel drug discovery process from natural products. In this study, we developed a novel computational pipeline for assisting de novo identification of protein targets for herbal ingredients. The pipeline involves pharmacophore comparison and reverse ligand-protein docking simulation in a high throughput manner. We evaluated the pipeline using three traditional Chinese medicine ingredients such as acteoside, quercetin, and epigallocatechin gallate as examples. A majority of current known targets of these ingredients were successfully identified by the pipeline. Structural comparative analyses confirmed that the predicted ligand-target interactions used the same binding pockets and binding modes as those of known ligand-target interactions. Furthermore, we illustrated the mechanism of actions of the ingredients by constructing the pharmacological networks on the basis of the predicted target profiles. In summary, we proposed an efficient and economic option for large-scale target exploration in the herb study. This pipeline will be particularly valuable in aiding precise drug discovery and drug repurposing from natural products.

Cyadox regulates the transcription of different genes by activation of the PI3K signaling pathway in porcine primary hepatocytes

Cyadox, a new derivative of quinoxalines, has been ascertained as an antibiotic with significant growth promoting, low poison, quick absorption, swift elimination, brief residual period, and noncumulative effect. Seven differential expressed genes, including Insulin-like Growth Factor-1 ( IGF-1), Epidermal Growth Factor ( EGF), Poly ADP-ribose polymerase ( PARP), the Defender Against Apoptotic Death 1 ( DAD1), Complement Component 3 ( C3), Transketolase ( TK) and a New gene, were induced by cyadox in swine liver tissues by messenger RNA differential display reverse transcription polymerase chain reaction (DDRT-PCR) in our laboratory. However, the signal mechanism that cyadox altered these genes expression is not completely elucidated. The signaling pathways involved in the expressions of seven genes induced by cyadox were determined in porcine primary hepatocytes by RT-qPCR and the application of various signal pathway inhibitors. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay revealed that cyadox could stimulate proliferation of porcine primary hepatocytes in a time-dependent manner. In porcine primary cultured hepatocytes, phosphoinositide 3-kinase (PI3K) and transforming growth factor-β (TGF-β) signal pathways were the main signal pathways involved in the expressions of seven genes induced by cyadox. Taken together, these results demonstrate for the first time that seven cyadox-related genes expressions in porcine primary hepatocytes treated with cyadox are mediated mainly through the PI3K signaling pathway, potentially leading to enhanced cell growth and cell immunity. EGF might be the early response gene of cyadox, and a primary regulator of the other gene expressions such as IGF-1 and DAD1, playing an important role in cell proliferation promoted by cyadox.

Therapeutic Options for Metastatic Breast Cancer

Metastatic breast cancer is the most common cancer in women after skin cancer, with a 5-year survival rate of 26%. Due to its high prevalence, it is important to develop therapies that go beyond those that just provide palliation of symptoms. Currently, there are several types of therapies available to help treat breast cancer including: hormone therapy, immunotherapy, and chemotherapy, with each one depending on both the location of metastases and morphological characteristics. Although technological and scientific advancements continue to pave the way for improved therapies that adopt a targeted and personalized approach, the fact remains that the outcomes of current first-line therapies have not significantly improved over the last decade. In this chapter, we review the current understanding of the pathology of metastatic breast cancer before thoroughly discussing local and systemic therapies that are administered to patients diagnosed with metastatic breast cancer. In addition, our review will also elaborate on the genetic profile that is characteristic of breast cancer as well as the local tumor microenvironment that shapes and promotes tumor growth and cancer progression. Lastly, we will present promising novel therapies being developed for the treatment of this disease.

Raddeanin A inhibits growth and induces apoptosis in human colorectal cancer through downregulating the Wnt/β-catenin and NF-κB signaling pathway

AIMS

Colorectal cancer (CRC) remains one of the most lethal human malignancies with high incidence and lack of effective therapy. Raddeanin A (RA), an active triterpenoid saponins, has been demonstrated the ability to inhibit the growth of tumor. But the therapeutic effects and mechanisms of RA in CRC remain elusive. Here, we investigated the efficacy and mechanism of RA in CRC both in vitro and in vivo.

MAIN METHODS

Cell viability was investigated to evaluate cytotoxic activity by MTT method. Apoptosis induced by RA was studied using Annexin V-FITC/PI binding and JC-1 staining by flow cytometry analysis. The xenograft mouse model of CRC was used to investigate anti-tumor effects in vivo. The key proteins involved in mitochondrial apoptotic, Wnt/β-catenin and NF-κB pathway were detected by Western blotting, Immunofluorescence, and Immunohistochemistry.

KEY FINDINGS

RA induced apoptosis and inhibited cell proliferation of SW480 and LOVO cells in a concentration-dependent manner. Moreover, RA efficiently inhibited tumor growth in xenograft mouse model. RA could down regulate the Wnt/β-catenin signaling to display anti-tumor effects via suppression of p-LRP6, induction of AKT inactivation, removal of GSK-3β inhibition and attenuation of β-catenin. Meanwhile, RA also suppressed the NF-κB pathway by decreasing the phosphorylation of IKBα to induce subsequently mitochondrial apoptotic pathway.

SIGNIFICANCE

In summary, RA suppressed the growth and triggered the apoptosis of CRC through discontinuing Wnt/β-catenin signaling and inhibiting the NF-κB pathway. These findings suggested that RA may hold a promise as a novel therapeutic agent for CRC therapy.

Involvement of α-methylene-γ- and δ-lactones in the suppression of multidrug resistance in MCF-7 cells

BACKGROUND

The development of multidrug resistance to chemotherapy remains a challenge in the treatment of cancer and is a major factor causing failure of many forms of chemotherapy. The ATP binding cassette (ABC) family of proteins are efflux pumps that transport various potentially dangerous substances out of the cells. Several of the ABC transporters are related to chemoresistance, as the rapidly dividing malignant cells use them to protect themselves from medical interventions. Inhibitors of ABC transporters have the potential to enhance the efficacy of anticancer drugs. Two new synthetic compounds, AD-06 and AD-013, were tested as possible multidrug resistance inhibitors in MCF-7 cells.

METHODS

The cytotoxicity of new compounds was tested in MCF-7 and MCF-10A cell lines using the MTT method. Gene expression was measured by real-time PCR and changes in the protein levels were evaluated by flow cytometry and ELISA. A method based on the use of a fluorescent dye, being a marker of the ABC transporter activity, was used for screening the tested compounds as potential multidrug resistance inhibitors.

RESULTS

AD-06 and AD-013 down-regulated NF-κB mRNA levels and decreased the population of cells with activated NF-κB. Both compounds were found to be strong ABCB1 and ABCG2 transporter inhibitors. They showed synergistic effects when incubated with taxol or oxaliplatin.

CONCLUSIONS

α-Methylene-γ- and -δ-lactones AD-06 and AD-013 are promising lead structures for further development as multidrug resistance inhibitors.

Thalidomide potentiates etoposide-induced apoptosis in murine neuroblastoma through suppression of NF-κB activation

PURPOSE

Treatment for high-risk neuroblastoma is still challenging. The purpose of the present study was to determine whether thalidomide suppresses etoposide-induced NF-κB activation and thus potentiates apoptosis in murine neuroblastoma.

METHODS

A murine neuroblastoma cell line, C1300, and A/J mice were used in this study. We evaluated NF-κB activation after using etoposide with or without thalidomide by quantitative analysis of NF-κB by ELISA and by Western blot analysis of IκB phosphorylation in vitro and in vivo. Induction of apoptosis was evaluated by Western blot analysis of the apoptotic signals caspase-3, 8, and 9 in vitro and by TUNEL assays in vivo. We also evaluated the efficacy of the combination of etoposide and thalidomide by assessing tumor growth and mouse survival in vivo.

RESULTS

Etoposide activated NF-κB in C1300 cells. This activation was suppressed by thalidomide and IκB was re-upregulated. The apoptotic signals were enhanced by the combination of thalidomide and etoposide compared with etoposide alone in vitro, which was consistent with TUNEL assays. The combination of etoposide and thalidomide also slowed tumor growth and mouse survival.

CONCLUSION

Thalidomide potentiates etoposide-induced apoptosis in murine neuroblastoma by suppressing NF-κB.

RIP2 enhances cell survival by activation of NF-ĸB in triple negative breast cancer cells

Receptor-interacting protein 2 (RIP2) is an essential mediator of inflammation and innate immunity, but little is known about its role outside the immune system. Recently, RIP2 has been linked to chemoresistance of triple negative breast cancer (TNBC), the most aggressive breast cancer subtype for which there is an urgent need for targeted therapies. In this study we show that high expression of RIP2 in breast tumors correlates with a worse prognosis and a higher risk of recurrence. We also demonstrate that RIP2 confers TNBC cell resistance against paclitaxel and ceramide-induced apoptosis. Overexpression of RIP2 lead to NF-κB activation, which contributed to higher expression of pro-survival proteins and cell survival. Conversely, RIP2 knockdown inhibited NF-κB signaling, reduced levels of anti-apoptotic proteins and sensitized cells to drug treatment. Together, these data show that RIP2 promotes survival of breast cancer cells through NF-κB activation and that targeting RIP2 may be therapeutically beneficial for treatment of TNBC.

Potential use of chymotrypsin-like proteasomal activity as a biomarker for prostate cancer

Although it is the most widely used biomarker for prostate cancer, the use of prostate specific antigen (PSA) is controversial due to its limitations in specificity and sensitivity. The proteasome is a complex associated with cell proliferation and apoptosis, and the abnormity of these processes may lead to tumor occurrence. Previous studies have reported that proteasomal activity is associated with cancer progression and can be used in risk stratification. The purpose of the present study was thus to investigate the feasibility of proteasome activity as a biomarker for prostate cancer. Proteasome activity in vitro and in vivo was detected, along with the expression of the substrate proteins NF-κB inhibitor-α (IκB-α), Bcl-2-associated X (Bax) and p27. Chymotrypsin-like proteasomal activity was elevated by 70% in vitro and 23% in vivo, and the expression levels of the proteasome substrate proteins IκB-α, Bax and p27 were decreased in prostate cancer cells and prostate tumor xenografts compared with normal mouse prostate tissue. In conclusion, proteasomal chymotrypsin-like activity maybe a potential biomarker for prostate cancer, and may be suitable to supplement PSA in clinical application for prostate cancer diagnosis.

Proteasome Inhibitor Carbobenzoxy-L-Leucyl-L-Leucyl-L-Leucinal (MG132) Enhances Therapeutic Effect of Paclitaxel on Breast Cancer by Inhibiting Nuclear Factor (NF)-κB Signaling

Background

Carbobenzoxy-L-leucyl-L-leucyl-L-leucinal (MG132), a peptide aldehyde proteasome inhibitor, can inhibit tumor progression by inactivating nuclear factor (NF)-κB signaling. Paclitaxel (PTX) is part of a routine regimen for the treatment of breast cancer. However, activation of the NF-κB pathway after treatment with PTX confers insensitivity to this drug. This study investigated the potential effect of MG132 as a co-treatment with PTX against breast cancer, and clarifies the underlying molecular mechanisms.

Material/Methods

Breast cancer cells were treated with PTX, MG132, or PTX plus MG132, and the therapeutic effects were evaluated phenotypically. A mouse model of breast cancer was used to determine the combined effect of PTX plus MG132 in vivo.

Results

Treatment with PTX plus MG132 suppressed aggressive phenotypes of breast cancer cells more effectively than PTX alone. Consistently, MG132 also enhanced the suppressive effect of PTX on tumor growth in C57BL/6 mice. Significantly, activation of the NF-κB pathway by PTX was attenuated by MG132.

Conclusions

Based on our findings, we suggest the application of MG132 in clinical practice in combination with PTX for the treatment of breast cancer.

The oncogenic Golgi phosphoprotein 3 like overexpression is associated with cisplatin resistance in ovarian carcinoma and activating the NF-κB signaling pathway

Background

Chemo-resistance is a leading cause of tumor relapse and treatment failure in patients with ovarian cancer. The identification of effective strategies to overcome drug resistance will have a significant clinical impact on the disease.

Methods

The protein and mRNA expression of GOLPH3L in ovarian cancer cell lines and patient tissues were determined using Real-time PCR and Western blot, respectively. 177 human ovarian cancer tissue samples were analyzed by IHC to investigate the association between GOLPH3L expression and the clinicopathological characteristics of ovarian cancer patients. Functional assays, such as MTT, FACS, and Tunel assay used to determine the oncogenic role of GOLPH3L in human ovarian cancer progression. Furthermore, western blotting and luciferase assay were used to determine the mechanism of GOLPH3L promotes chemoresistance in ovarian cancer cells.

Results

The expression of GOLPH3L was markedly upregulated in ovarian cancer cell lines and tissues, and high GOLPH3L expression was associated with an aggressive phenotype and poor prognosis with ovarian cancer patients. GOLPH3L overexpression confers CDDP resistance on ovarian cancer cells; however, inhibition of GOLPH3L sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. Additionally, GOLPH3L upregulated the levels of nuclear p65 and phosphorylated inhibitor of nuclear factor Kappa-B kinase-β and IκBα, thereby activating canonical nuclear factor-κB (NF-κB) signaling.

Conclusions

Our findings suggest that GOLPH3L is a potential therapeutic target for the treatment of ovarian cancer: targeting GOLPH3L signaling may represent a promising strategy to enhance platinum response in patients with chemoresistant ovarian cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0607-0) contains supplementary material, which is available to authorized users.

An autocrine inflammatory forward-feedback loop after chemotherapy withdrawal facilitates the repopulation of drug-resistant breast cancer cells

Stromal cells, infiltrating immune cells, paracrine factors and extracellular matrix have been extensively studied in cancers. However, autocrine factors produced by tumor cells and communications between autocrine factors and intracellular signaling pathways in the development of drug resistance, cancer stem-like cells (CSCs) and tumorigenesis have not been well investigated, and the precise mechanism and tangible approaches remain elusive. Here we reveal a new mechanism by which cytokines produced by breast cancer cells after chemotherapy withdrawal activate both Wnt/β-catenin and NF-κB pathways, which in turn further promote breast cancer cells to produce and secrete cytokines, forming an autocrine inflammatory forward-feedback loop to facilitate the enrichment of drug-resistant breast cancer cells and/or CSCs. Such an unexpected autocrine forward-feedback loop and CSC enrichment can be effectively blocked by inhibition of Wnt/β-catenin and NF-κB signaling. It can also be diminished by IL8-neutralizing antibody or blockade of IL8 receptors CXCR1/2 with reparixin. Administration of reparixin after chemotherapy withdrawal effectively attenuates tumor masses in a human xenograft model and abolishes paclitaxel-enriched CSCs in the secondary transplantation. These results are partially supported by the latest clinical data set. Breast cancer patients treated with chemotherapeutic drugs exhibited poor survival rate (66.7 vs 282.8 months, P=0.00071) and shorter disease-free survival time if their tumor samples expressed high level of IL8, CXCR1, CXCR2 genes and Wnt target genes. Taken together, this study provides new insights into the communication between autocrine niches and signaling pathways in the development of chemotherapy resistance and CSCs; it also offers a tangible approach in breast cancer treatment.

Garcinol sensitizes breast cancer cells to Taxol through the suppression of caspase-3/iPLA2 and NF-κB/Twist1 signaling pathways in a mouse 4T1 breast tumor model

Breast cancer is a significant threat to women's health and has high incidence and mortality. Metastasis in breast cancer patients is a major cause of cancer deaths among women worldwide. Clinical experience suggests that patients with metastatic triple-negative breast cancer (TNBC) relapse quickly and often have chemotherapy resistance. Taxol (paclitaxel) is an effective chemotherapeutic agent for treating metastatic breast cancer, but Taxol at high doses can cause adverse effects and recurrent resistance. Thus, the selection of a synergistic combination therapy is recommended, which is safer and has a more significant response rate than monotherapy. In this study, our strategy is to combine a low dose of Taxol (5 mg kg^-1, i.p.) and garcinol (1 mg kg^-1, i.g.) to investigate the synergistic antitumor and anti-metastasis effects and to determine the underlying mechanisms of these effects in vivo. For the in vivo study, metastasis-specific mouse mammary carcinoma 4T1 cells were inoculated in Balb/c mice to establish an orthotopic primary tumor and spontaneous metastasis model. Tumor growth and metastases were monitored. The mechanisms of synergistic efficacies were evaluated at different signaling pathways, including proliferation, survival, and epithelial-mesenchymal transition (EMT)-regulated metastatic propensity. We demonstrated that garcinol combined with Taxol significantly increased the therapeutic efficacy when compared with either treatment alone. The synergistic antitumor and anti-metastasis effects were enhanced primarily through the induction of Taxol-stimulated G2/M phase arrest and the inhibition of caspase-3/cytosolic Ca²⁺-independent phospholipase A2 (iPLA₂) and nuclear factor-κB (NF-κB)/Twist-related protein 1 (Twist1) drive downstream events including tumor cell repopulation, survival, inflammation, angiogenesis, invasion, and EMT. Our current findings provide the first experimental evidence that a combination of a low dose of Taxol and garcinol is a promising therapeutic strategy for controlling advanced or metastatic breast cancer. Finally, our results also point to the possible role of NF-κB/Twist1 and caspase-3/iPLA₂ signaling pathways as biomarkers to predict the tumor response to treatment.

Synthesis of dual-action parthenolide prodrugs as potent anticancer agents

Cancer stem cells are responsible for the failure of a large number of cancer treatments and the re-emergence of cancer in patients. Parthenolide is a potent anticancer sesquiterpene lactone that is also able to kill cancer stem cells. The main problem with this compound is its poor solubility in water. To solve this problem, medicinal chemists have tried to prepare amino-derivatives of parthenolide, however, most amino-derivatives have less potency than that of parthenolide. In this paper, we proposed a new approach to synthesize parthenolide derivatives with better solubility and higher potency. We prepared novel parthenolide derivatives through the aza-Michael addition of nitrogen-containing anticancer drug molecules (cytarabine and melphalan) to the α-methylene-γ-lactone group of parthenolide. Different types of catalysts were used to catalyze the aza-Michael addition. Among all the used catalysts, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) was found to have the highest catalytic activity. In addition, we examined the effects of parthenolide-anticancer drug hybrids on the growth and proliferation of three cancer cell lines (MCF-7, LNcaP, Hep G2) and CHO. The parthenolide prodrugs showed potent cytotoxic property with IC₅₀ values ranging from 0.2 to 5.2μM, higher than those of parthenolide and anticancer drugs (cytarabine and melphalan).

A transcriptome-based model of central memory CD4 T cell death in HIV infection

BACKGROUND

Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state.

METHODS

Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log₂ Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses.

RESULTS

Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1β, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection.

CONCLUSIONS

Our findings support a model where progressive loss of central memory CD4 T cells in chronic HIV-1 infection is driven by increased cell cycle entry followed by mitotic arrest, leading to a non-apoptotic death pathway without actual proliferation, possibly contributing to increased turnover.

UBXD Proteins: A Family of Proteins with Diverse Functions in Cancer

The UBXD family is a diverse group of UBX (ubiquitin-regulatory X) domain-containing proteins in mammalian cells. Members of this family contain a UBX domain typically located at the carboxyl-terminal of the protein. In contrast to the UBX domain shared by all members of UBXD family, the amino-terminal domains are diverse and appear to carry out different roles in a subcellular localization-dependent manner. UBXD proteins are principally associated with the endoplasmic reticulum (ER), where they positively or negatively regulate the ER-associated degradation machinery (ERAD). The distinct protein interaction networks of UBXD proteins allow them to have specific functions independent of the ERAD pathway in a cell type- and tissue context-dependent manner. Recent reports have illustrated that a number of mammalian members of the UBXD family play critical roles in several proliferation and apoptosis pathways dysregulated in selected types of cancer. This review covers recent advances that elucidate the therapeutic potential of selected members of the UBXD family that can contribute to tumor growth.

Molecular Pathways: The Balance between Cancer and the Immune System Challenges the Therapeutic Specificity of Targeting Nuclear Factor-κB Signaling for Cancer Treatment

The NF-κB signaling pathway is a complex network linking extracellular stimuli to cell survival and proliferation. Cytoplasmic signaling to activate NF-κB can occur as part of the DNA damage response or in response to a large variety of activators, including viruses, inflammation, and cell death. NF-κB transcription factors play a fundamental role in tumorigenesis and are implicated in the origination and propagation of both hematologic and solid tumor types, including melanoma, breast, prostate, ovarian, pancreatic, colon, lung, and thyroid cancers. On the other hand, NF-κB signaling is key to immune function and is likely necessary for antitumor immunity. This presents a dilemma when designing therapeutic approaches to target NF-κB. There is growing interest in identifying novel modulators to inhibit NF-κB activity as impeding different steps of the NF-κB pathway has potential to slow tumor growth, progression, and resistance to chemotherapy. Despite significant advances in our understanding of this pathway, our ability to effectively clinically block key targets for cancer therapy remains limited due to on-target effects in normal tissues. Tumor specificity is critical to developing therapeutic strategies targeting this antiapoptotic signaling pathway to maintain antitumor immune surveillance when applying such therapy to patients. Clin Cancer Res; 22(17); 4302-8. ©2016 AACR.

New treatment strategy with nuclear factor-κB inhibitor for pancreatic cancer

BACKGROUND

Because of difficulties with early diagnosis, most patients with pancreatic cancer receive chemotherapy. The National Comprehensive Cancer Network guidelines (version 2.2015) suggest therapy with gemcitabine (GEM) plus nab-paclitaxel (nPTX) as a category 1 recommendation for metastatic pancreatic ductal adenocarcinoma. According to the results of many studies, the activation of chemotherapeutic agents-induced nuclear factor-κB (NF-κB) causes chemoresistance. Hence, we hypothesized that the addition of nafamostat mesilate (NM), a potent NF-κB inhibitor, to GEM/nPTX therapy could enhance the antitumor effect in the treatment of pancreatic ductal adenocarcinoma.

MATERIALS AND METHODS

In vitro, we assessed NF-κB activity and apoptosis under treatment with NM alone (80 μg/mL), with GEM/nPTX, or with a combination of NM and GEM/nPTX in human pancreatic cancer cell lines (PANC-1, MIA PaCa-2, and AsPC-1). In vivo, orthotopic pancreatic cancer mice (BALBc nu/nu) were divided into four groups: control (n = 13), NM (n = 13), GEM/nPTX (n = 13), and triple combination (n = 13). NM (30 mg/kg) was delivered intraperitoneally three times a week, and GEM/nPTX was injected intravenously once a week to orthotopic pancreatic cancer model mice. In the triple combination group, mice received NM followed by GEM/nPTX on the first day to avoid GEM/nPTX-induced NF-κB activation.

RESULTS

In vitro and in vivo, NM inhibited GEM/nPTX-induced NF-κB activation, and a synergistic effect of apoptosis was observed in the triple combination group. Furthermore, tumor growth was significantly suppressed in the triple combination group compared with the other groups.

CONCLUSIONS

NM enhances the antitumor effect of GEM/nPTX chemotherapy for orthotopic pancreatic cancer by inhibition of NF-κB activation.

Lineage-Specific Early Differentiation of Human Embryonic Stem Cells Requires a G2 Cell Cycle Pause

Human embryonic stem cells (hESCs) have an abbreviated G1 phase of the cell cycle that allows rapid proliferation and maintenance of pluripotency. Lengthening of G1 corresponds to loss of pluripotency during differentiation. However, precise mechanisms that link alterations in the cell cycle and early differentiation remain to be defined. We investigated initial stages of mesendodermal lineage commitment in hESCs, and observed a cell cycle pause. Transcriptome profiling identified several genes with known roles in regulation of the G2/M transition that were differentially expressed early during lineage commitment. WEE1 kinase, which blocks entry into mitosis by phosphorylating CDK1 at Y15, was the most highly expressed of these genes. Inhibition of CDK1 phosphorylation by a specific inhibitor of WEE1 restored cell cycle progression by preventing the G2 pause. Directed differentiation of hESCs revealed that cells paused during commitment to the endo- and mesodermal, but not ectodermal, lineages. Functionally, WEE1 inhibition during meso- and endodermal differentiation selectively decreased expression of definitive endodermal markers SOX17 and FOXA2. Our findings identify a novel G2 cell cycle pause that is required for endodermal differentiation and provide important new mechanistic insights into early events of lineage commitment. Stem Cells 2016;34:1765-1775.