Curcumin induces apoptosis in p53-null Hep3B cells through a TAp73/DNp73-dependent pathway

Curcumin and its Derivatives Targeting Multiple Signaling Pathways to Elicit Anticancer Activity: A Comprehensive Perspective

The uncontrolled growth and spread of aberrant cells characterize the group of disorders known as cancer. According to GLOBOCAN 2022 analysis of cancer patients in either developed countries or developing countries the main concern cancers are breast cancer, lung cancer, and liver cancer which may rise eventually. Natural substances with dietary origins have gained interest for their low toxicity, anti-inflammatory, and antioxidant effects. The evaluation of dietary natural products as chemopreventive and therapeutic agents, the identification, characterization, and synthesis of their active components, as well as the enhancement of their delivery and bioavailability, have all received significant attention. Thus, the treatment strategy for concerning cancers must be significantly evaluated and may include the use of phytochemicals in daily lifestyle. In the present perspective, we discussed one of the potent phytochemicals, that has been used over the past few decades known as curcumin as a panacea drug of the "Cure-all" therapy concept. In our review firstly we included exhausted data from in vivo and in vitro studies on breast cancer, lung cancer, and liver cancer which act through various cancer-targeting pathways at the molecular level. Now, the second is the active constituent of turmeric known as curcumin and its derivatives are enlisted with their targeted protein in the molecular docking studies, which help the researchers design and synthesize new curcumin derivatives with respective implicated molecular and cellular activity. However, curcumin and its substituted derivatives still need to be investigated with unknown targeting mechanism studies in depth.

miR-96-5p is involved in alcohol-induced apoptosis in PC12 cells via negatively regulating TAp73

OBJECTIVE

The present study opted for the adrenal phaeochromocytoma (PC12) cell line to frame a neuronal injury model induced by alcohol exposure in vitro, aiming to probe whether TAp73 and miR-96-5p are involved in the neuronal injury process induced by alcohol and elucidate the regulatory relationship between miR-96-5p and TAp73.

METHODS

Immunofluorescence staining was used to observe the structural features of PC12 cells after culturing in medium with nerve growth factor (NGF). After different doses and different durations of alcohol treatment, CCK-8 assay was performed to detect the viability of PC12 cells, flow cytometry assay was carried out to detect the apoptosis rate of PC12 cells, dual-luciferase reporter assay was used to definitude the regulatory relationship between miR-96-5p and Tp73, and western blot was used to detect the protein expression of TAp73.

RESULTS

The result of immunofluorescence staining demonstrated that PC12 cells abundantly expressed Map2, CCK-8 assay illustrated alcohol exposure significantly downregulated the cell viability of PC12 cells, Treatment with miR-96-5p inhibitor induced apoptosis and upregulated the expression of TAp73 in PC12 cells. Contrastingly, miR-96-5p mimic reversed the above effects and downregulation of TAp73 inhibited the apoptosis of PC12 cells.

CONCLUSION

The present study demonstrated that miR-96-5p participates in alcohol-induced apoptosis in PC12 cells via negatively regulating TAp73.

Inhibition of apoptosis via CHIP-mediated proteasomal degradation of TAp73α

TAp73, a homologous of tumor suppressor p53, regulates apoptosis in a p53-independent manner and its suppressive as well as stimulatory role in promoting angiogenesis has been reported. It exists in multiple isoforms which varies structurally in their N-terminus and C-terminus region and crucial interplay among them guides the decision of cell survival and death. As molecular chaperones control both stability and degradation of TAp73, selective regulation of p73 isoforms has implication upon developing new therapeutic for hypoxic tumor. We have discovered that under DNA damage carboxy terminus Hsp70 interacting protein (CHIP's) antiapoptotic function is displayed via its E3 ligase activity that inhibits exclusively TAp73α-mediated apoptosis in cancer cell. The decrease in TAp73α level by CHIP as it is supported by increased ubiquitination pattern is reverted back by sh-CHIP. Further, the transactivation of p53-downstream apoptotic genes BAX, PUMA and PIG3 by TAp73α is also shown to be subsequently inhibited by CHIP. The tetratricopeptide TPR-domain of CHIP in its amino-terminus interacts with the carboxy-terminus of TAp73α and ΔNp73α and as a result, U-BOX domain of CHIP in the carboxy-terminus is able to ubiquitinate TAp73α for proteasomal degradation. Due to lack of C-terminus in TAp73β, CHIP fails to interact with and degrade it. In conclusion, we have thus uncovered for the first time a novel mechanism of chaperone-assisted regulation of p73 stability as well as its apoptotic functions by CHIP that might be utilized to develop new anticancer strategies.

Mechanism of Apoptosis Induced by Curcumin in Colorectal Cancer

Colorectal cancer (CRC) is among the top three cancer with higher incident and mortality rate worldwide. It is estimated that about over than 1.1 million of death and 2.2 million new cases by the year 2030. The current treatment modalities with the usage of chemo drugs such as FOLFOX and FOLFIRI, surgery and radiotherapy, which are usually accompanied with major side effects, are rarely cured along with poor survival rate and at higher recurrence outcome. This trigger the needs of exploring new natural compounds with anti-cancer properties which possess fewer side effects. Curcumin, a common spice used in ancient medicine was found to induce apoptosis by targeting various molecules and signaling pathways involved in CRC. Disruption of the homeostatic balance between cell proliferation and apoptosis could be one of the promoting factors in colorectal cancer progression. In this review, we describe the current knowledge of apoptosis regulation by curcumin in CRC with regard to molecular targets and associated signaling pathways.

Potential Mechanisms of Action of Curcumin for Cancer Prevention: Focus on Cellular Signaling Pathways and miRNAs

Despite significant progressions in treatment modalities over the last decade, either cancer incidence or mortality is continuously on the rise throughout the world. Current anticancer agents display limited efficacy, accompanied by severe side effects. In order to improve therapeutic outcomes in patients with cancer, it is crucial to identify novel, highly efficacious pharmacological agents. Curcumin, a hydrophobic polyphenol extracted from turmeric, has gained increasing attention due to its powerful anticancer properties. Curcumin can inhibit the growth, invasion and metastasis of various cancers. The anticancer mechanisms of curcumin have been extensively studied. The anticancer effects of curcumin are mainly mediated through its regulation of multiple cellular signaling pathways, including Wnt/β-catenin, PI3K/Akt, JAK/STAT, MAPK, p53 and NF-ĸB signaling pathways. Moreover, curcumin also orchestrates the expression and activity of oncogenic and tumor-suppressive miRNAs. In this review, we summarized the regulation of these signaling pathways by curcumin in different cancers. We also discussed the modulatory function of curcumin in the downregulation of oncogenic miRNAs and the upregulation of tumor-suppressive miRNAs. An in-depth understanding of the anticancer mechanisms of curcumin will be helpful for developing this promising compound as a therapeutic agent in clinical management of cancer.

Role of curcumin in regulating p53 in breast cancer: an overview of the mechanism of action

p53 is a tumor suppressor gene involved in various cellular mechanisms including DNA repair, apoptosis, and cell cycle arrest. More than 50% of human cancers have a mutated nonfunctional p53. Breast cancer (BC) is one of the main causes of cancer-related deaths among females. p53 mutations in BC are associated with low survival rates and more resistance to the conventional therapies. Thus, targeting p53 activity was suggested as an important strategy in cancer therapy. During the past decades, cancer research was focused on the development of monotargeted anticancer therapies. However, the development of drug resistance by modulation of genes, proteins, and pathways was the main hindrance to the success of such therapies. Curcumin is a natural product, extracted from the roots of Curcuma longa, and possesses various biological effects including anticancer activity. Previous studies proved the ability of curcumin to modulate several signaling pathways and biomolecules in cancer. Safety and cost-effectiveness are additional inevitable advantages of curcumin. This review summarizes the effects of curcumin as a regulator of p53 in BC and the key molecular mechanisms of this regulation.

KCTD11 inhibits growth and metastasis of hepatocellular carcinoma through activating Hippo signaling

A lack of effective prognostic biomarkers and molecular targets is a serious problem in hepatocellular carcinoma. KCTD11, reported as a tumor suppressor, are still not well understood. In this study, KCTD11 was found low-expressed in HCC tissues and cell lines. The HCC patients with low expression of KCTD11 suggested shorter overall survival. We found KCTD11 inhibiting cell proliferation in vitro and tumor growth in vivo, by activating p21 and repressing cycle related proteins. KCTD11 also inhibited cell adhesion by decreasing CTGF and CLDN1. We found CTGF binding COL3A1 in HCCLM3, which might lead to reduction of COL3A1 expression. KCTD11 also inhibited cell migration and invasion in HCC, by repressing MMPs and EMT. We found the tumor suppression function of KCTD11 was at least partly through activating Hippo pathway in HCC. Base on the enhanced Hippo pathway, KCTD11 could activate p21 by stabilizing p53 or promoting the MST1/ GSK3β/p21 signaling in HCC. Overall, these results suggest that KCTD11 works as a tumor suppressor and owns prognostic and therapeutic potentials in HCC.

Micellar Delivery of miR-34a Modulator Rubone and Paclitaxel in Resistant Prostate Cancer

Treatment of prostate cancer with paclitaxel often fails due to the development of chemoresistance caused by downregulation of the tumor suppressor gene miR-34a. In this study, we demonstrate that codelivery of paclitaxel and 2'-hydroxy-2,4,4',5,6'-pentamethoxychalcone (termed rubone) drives upregulation of miR-34a and chemosensitizes paclitaxel-resistant prostate cancer cells, killing both cancer stem-like cells (CSC) and bulk tumor cells. Rubone upregulated miR-34a and reversed its downstream target genes in DU145-TXR and PC3-TXR cells. Paclitaxel and rubone combination therapy inhibited tumor cell growth, migration, and CSC population growth. We synthesized poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate-graft-dodecanol; PEG-PCD) to prepare micelles. The drug-loading capacities were 9.70% ± 0.10% and 5.34% ± 0.02% for paclitaxel and rubone, respectively, controlling a drug release of 60.20% ± 2.67% and 60.62% ± 4.35% release of paclitaxel and rubone at 24 hours. Delivery of miR-34a and rubone decreased PC3-TXR cell viability with increasing paclitaxel concentration. Coincubation with a miR-34a inhibitor diminished the effect of rubone. Paclitaxel IC₅₀ in PC3 and PC3-TXR cells was 55.6 and 2,580 nmol/L, respectively, but decreased to 49.8 and 93.2 nmol/L when treated in combination with rubone, demonstrating a reversal of paclitaxel resistance by rubone. Systemic administration of micelles carrying paclitaxel and rubone inhibited orthotopic prostate tumor growth in nude mice, compared with monotherapy, by reversing the expression of miR-34a, SIRT1, cyclin D1, and E-cadherin. In summary, our results showed how rubone acts as an efficient small-molecule modulator of miR-34a to reverse chemoresistance and further enhance the therapeutic efficacy of paclitaxel in paclitaxel-resistant prostate cancer. Cancer Res; 77(12); 3244-54. ©2017 AACR.

Unraveling the Anticancer Effect of Curcumin and Resveratrol

Resveratrol and curcumin are natural products with important therapeutic properties useful to treat several human diseases, including cancer. In the last years, the number of studies describing the effect of both polyphenols against cancer has increased; however, the mechanism of action in all of those cases is not completely comprehended. The unspecific effect and the ability to interfere in assays by both polyphenols make this challenge even more difficult. Herein, we analyzed the anticancer activity of resveratrol and curcumin reported in the literature in the last 11 years, in order to unravel the molecular mechanism of action of both compounds. Molecular targets and cellular pathways will be described. Furthermore, we also discussed the ability of these natural products act as chemopreventive and its use in association with other anticancer drugs.