Apoptosis-associated speck-like protein containing a CARD regulates the growth of pancreatic ductal adenocarcinoma

Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is a key adaptor protein of inflammasomes and a proapoptotic molecule; however, its roles in signal transduction in pancreatic ductal adenocarcinoma (PDAC) cells remain unknown. Here, we clarified the role and mechanisms of action of ASC in PDAC using clinical evidence and in vitro data. ASC expression in PDAC tissues was analyzed using public tumor datasets and immunohistochemistry results of patients who underwent surgery, and PDAC prognosis was investigated using the Kaplan–Meier Plotter. ASC expression in PDAC cells was downregulated using small-interfering RNA, and gene expression was assessed by RNA sequencing. Review of the Oncomine database and immunostaining of surgically removed tissues revealed elevated ASC expression in PDAC tumors relative to non-tumor tissue, indicating poor prognosis. We observed high ASC expression in multiple PDAC cells, with ASC silencing subsequently inhibiting PDAC cell growth and altering the expression of cell cycle-related genes. Specifically, ASC silencing reduced cyclin D1 levels and stopped the cell cycle at the G1 phase but did not modulate the expression of any apoptosis-related molecules. These results show that ASC inhibited tumor progression via cell cycle modulation in PDAC cells and could be a potential therapeutic target.

Bortezomib Is Effective in Treating T-ALL, Inducting G2/M Cell Cycle Arrest and WEE1 Downregulation

T lymphoblastic leukaemia (T-ALL) is an aggressive haematological malignancy with poor outcome, especially for relapse/refractory disease. Early T- cell precursor acute lymphoblastic leukaemia (ETP-ALL) is a recently identified subtype of T-ALL with worse treatment outcome compared with other subtypes of T-ALL and treatment options are limited. T-ALL frequently harbors genetic aberrations leading to cell cycle dysregulation and it is one of the major molecular pathogenesis of T-ALL. WEE1 is a protein kinase that is responsible for inhibiting mitosis with unrepaired damaged DNA via inactivating CDK1. WEE1 is highly express in adult T-ALL and its overexpression is associated with adverse prognosis in various cancers. Inhibiting WEE1 expression is a novel approach of therapy. Bortezomib is a 26S proteosome inhibitor and it is FDA approved for treating plasma cell myeloma and mantle cell lymphoma. Bortezomib had been demonstrated therapeutic efficacy in clinical setting for relapse/refractory paediatric T-ALL and B-ALL when combined with chemotherapy. Despite its therapeutic efficacy in clinical studies, the mechanism of action of Bortezomib in T-ALL remain uncertain. The role of Bortezomib in cell cycle modulation had not been established in T-ALL. Moreover, it had not been demonstrated that the effect of Bortezomib in WEE1 expression in T-ALL. Here, we present our study that demonstrated the therapeutic efficacy of Bortezomib in treating T-ALL via cell cycle modulation and downregulation of WEE1 by Bortezomib. T-ALL cell lines including MOLT16, MOLT4, LOUCY and CEM were used in the study. Cell viability was measured by trypan blue. Apoptosis and cell cycle analysis were measured by flow cytometry. Western blot of WEE1, p53, cyclin B1, p21 and p27 were performed. Our result showed that Bortezomib reduce the cell viability of T-ALL cell lines in dose and time-dependent manner. Bortezomib was also sensitive towards LOUCY, a T-ALL cell line with ETP-ALL phenotype. It implied that Bortezomib could be a promising therapy for ETP-ALL. Bortezomib also triggered apoptosis in various T-ALL and the effect of apoptosis was more pronounced after 72 hours of treatment when compared with 24-hour. Again, Bortezomib was able to induce apoptosis in LOUCY cell line. G2/M cell cycle arrest was observed in various T-ALL upon treatment of Bortezomib. The effect on cell cycle modulation was also observed in LOUCY cell line. The protein expression of p21 and p27 were increased after the treatment of Bortezomib. The level of cyclin B1 was increased also. There was upregulation of p53 after Bortezomib treatment. Strikingly, the protein expression level of WEE1 was reduced. The findings of WEE1 downregulation by Bortezomib is a novel findings. We also showed that Bortezomib downregulate WEE1 mRNA expression by quantitative PCR. Our study showed that Bortezomib is active against T-ALL cell lines, including ETP-ALL cell line, LOUCY and modulates cell cycle with G2/M arrest. Bortezomib had been shown to increase the level of p21, p27 and cyclin B1 and induced G2/M cell cycle arrest in glioblastoma cells. However, studies on cell cycle modulation by Bortezomib in T-ALL are scarce. Here, we demonstrated Bortezomib stabilized p21, p27 and upregulation of cyclin B1 in T-ALL as well, which could account for the G2/M cell cycle arrest. We first showed that downregulation of WEE1 after treatment with Bortezomib, in protein level as well as in mRNA level. Recent study showed that inhibition of WEE1 is a novel target of therapy in T-ALL. WEE1 is upregulated in T-ALL to prevent entry of mitosis with unrepaired damaged DNA. The downregulation of WEE1 by Bortezomib as showed by our study could reverse its effect and leads to apoptosis of leukaemic cells. In summary, our study provides the insight on mechanism of action of Bortezomib in modulating cell cycle in T-ALL. Moreover, it is the first study to demonstrate WEE1 downregulation by Bortezomib in T-ALL. These findings not only enhance our understanding of mechanism of action of Bortezomib in T-ALL, but also rationalized the use of certain synergistics combination therapy with Bortezomib in treating T-ALL, e.g., chemotherapeutic agents, PARP inhibitors which could damage DNA of leukaemic cells. Further research is needed to explore those combination therapy in T-ALL and molecular mechanism of downregulation of WEE1 by Bortezomib in T-ALL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

The Role of ARID1A in Tumors: Tumor Initiation or Tumor Suppression?

Genes encoding subunits of SWItch/Sucrose Non-Fermenting (SWI/SNF) chromatin remodeling complexes are collectively mutated in 20% of all human cancers, among which the AT-rich interacting domain−containing protein 1A (ARID1A, also known as BAF250a, B120, C1orf4, Osa1) that encodes protein ARID1A is the most frequently mutated, and mutations in ARID1A have been found in various types of cancer. ARID1A is thought to play a significant role both in tumor initiation and in tumor suppression, which is highly dependent upon context. Recent molecular mechanistic research has revealed that ARID1A participates in tumor progression through its effects on control of cell cycle, modulation of cellular functions such as EMT, and regulation of various signaling pathways. In this review, we synthesize a mechanistic understanding of the role of ARID1A in human tumor initiation as well as in tumor suppression and further discuss the implications of these new discoveries for potential cancer intervention. We also highlight the mechanisms by which mutations affecting the subunits in SWI/SNF complexes promote cancer.

Molecular Biology for Cancer Therapy: Review Articles

introduction: Cancer, as clusters of diseases, uncontrolled cell proliferation due to tumor suppressor genes inactivation, oncogenes activation, and external factors.Methods: To review data, electronic databases such as Nature, PubMed/PMC, Science Direct/Elsevier, EMBASE, and Google Scholar were used.Results: Derestricted forms of proto-oncogenes are oncogenes, which had vital roles in various paths of cell cycle modulation. Translocations and chromosomal rearrangement and/or mutations in genes are the major factors for the transformation of proto-oncogene to oncogenes. Herein, to prevent the proliferation of cancerous cells, oncogenes are targeted molecules. From a cancer therapeutic target point of view, oncogene silencing and deletion, mutation of tumor suppressor genes, and retroviral therapy molecular techniques were developed. Conclusion: To establish a cancer-free world, the most commonly used techniques are: Ribose Nucleic Acid interferences, zinc finger nucleases, and CRISPR.Keywords: Cancer, Oncogenes, Proto-oncogenes, molecular technique

Chemoprotective Effects of Xanthohumol against the Carcinogenic Mycotoxin Aflatoxin B1

The present study addresses the chemoprotective effects of xanthohumol (XN), a prenylated flavonoid found in the female inflorescences (hops) of the plant Humulus lupulus L., against the carcinogenic food contaminant aflatoxin B1 (AFB1). The chemical reactions of XN and its derivatives (isoxanthohumol (IXN), 8-prenylnaringenin (8-PN), and 6-prenylnaringenin (6-PN)) with the AFB1 metabolite, aflatoxin B1 exo-8,9-epoxide (AFBO), were investigated in silico, by calculating activation free energies (ΔG⧧) at the Hartree–Fock level of theory in combination with the 6-311++G(d,p) basis set and two implicit solvation models. The chemoprotective effects of XN were investigated in vitro in the metabolically competent HepG2 cell line, analyzing its influence on AFB1-induced cytotoxicity using the MTS assay, genotoxicity using the comet and γH2AX assays, and cell cycle modulation using flow cytometry. Our results show that the ΔG⧧ required for the reactions of XN and its derivatives with AFBO are comparable to the ΔG⧧ required for the reaction of AFBO with guanine, indicating that XN, IXN, 8-PN, and 6-PN could act as scavengers of AFBO, preventing DNA adduct formation and DNA damage induction. This was also reflected in the results from the in vitro experiments, where a reduction in AFB1-induced cytotoxicity and DNA single-strand and double-strand breaks was observed in cells exposed to combinations of AFB1 and XN, highlighting the chemoprotective effects of this phytochemical.

Regulation of p27Kip1 and p57Kip2 Functions by Natural Polyphenols

In numerous instances, the fate of a single cell not only represents its peculiar outcome but also contributes to the overall status of an organism. In turn, the cell division cycle and its control strongly influence cell destiny, playing a critical role in targeting it towards a specific phenotype. Several factors participate in the control of growth, and among them, p27Kip1 and p57Kip2, two proteins modulating various transitions of the cell cycle, appear to play key functions. In this review, the major features of p27 and p57 will be described, focusing, in particular, on their recently identified roles not directly correlated with cell cycle modulation. Then, their possible roles as molecular effectors of polyphenols’ activities will be discussed. Polyphenols represent a large family of natural bioactive molecules that have been demonstrated to exhibit promising protective activities against several human diseases. Their use has also been proposed in association with classical therapies for improving their clinical effects and for diminishing their negative side activities. The importance of p27Kip1 and p57Kip2 in polyphenols’ cellular effects will be discussed with the aim of identifying novel therapeutic strategies for the treatment of important human diseases, such as cancers, characterized by an altered control of growth.

Ohmic Heating Extract of Vine Pruning Residue Has Anti-Colorectal Cancer Activity and Increases Sensitivity to the Chemotherapeutic Drug 5-FU

Vine pruning residues are by-products of the wine industry that have not received much attention in the past, in spite of being rich in bioactive compounds. In this study, we aimed to test whether an ohmic extract of vine pruning residue (VPE) has anti-colorectal cancer (CRC) properties, and whether responses differ according with cell’s mutation profile. VPE decreased human CRC cell proliferation, accompanied by DNA effects and cell cycle modulation. VPE also increased cell sensitivity to the chemotherapeutic drug 5-FU. Our results suggest that tumors harboring BRAF mutations may be more responsive to VPE than KRAS mutated tumors. These effects of the extract were not completely reproduced by the most abundant constituents tested individually at the concentrations present in the effective dose of VPE. Globally, our results indicate that VPE, a polyphenol enriched extract produced by ohmic heating of vine pruning residue, has anti-colorectal cancer potential, including sensitizing to a chemotherapeutical drug, and its use in functional foods or nutraceuticals could be exploited in personalized anti colorectal cancer dietary strategies. Valorization of this lignocellulosic residue should encourage bio-waste recycling, adding value to this agricultural by-product and promoting the sustainable use of natural resources.

Regulation of p27Kip1 and p57Kip2 Functions by Natural Polyphenols

In numerous instances, the fate of a single cell not only represents its peculiar outcome but also contributes to the overall status of an organism. In turn, cell division cycle and its control strongly influence cell destiny playing a critical role in targeting it towards a specific phenotype. Several factors participate to the control of growth and among them p27 and p57, two proteins modulating various transitions of cell cycle, appear to play key functions. In this review, the major features of p27 and p57 will be described, focusing in particular on their recently identified roles not directly correlated to cell cycle modulation. Then, their possible role as molecular effectors of polyphenols activities are discussed. Polyphenols represent a large family of natural bioactive molecules that have been demonstrated to play promising protective activities against several human diseases. Their use has also been proposed in association with classical therapies for ameliorating their clinical effects and for diminishing their negative side activities. The importance of p27 and p57 in polyphenol cellular effects will be discussed with the aim of identifying novel therapeutic strategies for the treatment of important human diseases, such as cancers, characterized by an altered control of growth.