Effect of glabridin combined with bakuchiol on UVB-induced skin damage and its underlying mechanism: An experimental study.

BACKGROUND: Research has demonstrated the anti-photoaging properties of glabridin and bakuchiol. METHODS: The impact of glabridin, glabridin + bakuchiol, and bakuchiol on the levels of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) in mice skin fibroblasts was observed. Furthermore, we investigated the potential roles of fibronectin (FN), interferon-γ (IFN-γ), interleukin-22 (IL-22), and transforming growth factor-ß (TGF-ß) in the tissues, and evaluated their impact on the enzymatic levels in the skin. In conjunction with transcriptomic analysis, metabolomic profiling, and network pharmacology, all samples underwent comprehensive metabolomic and principal component analysis. The Venny2.1 method was utilized to identify variances in shared metabolites between the treatment group and the UVB group, as well as between the UVB group and the control group. Subsequently, a cluster heat map was generated to forecast and analyze metabolic pathways and targets. RESULTS: The outcomes from the hematoxylin and eosin and toluidine blue staining revealed that glabridin and bakuchiol markedly decreased dermal thickness and suppressed mast cell infiltration in photoaged mice. Immunohistochemistry and Elisa analysis revealed that glabridin and bakuchiol effectively attenuated the levels of pro-inflammatory factors, including IL-1ß, tumor necrosis factor-α, IL-22, and IFN-γ. Furthermore, an increase in the levels of anti-inflammatory factors such as FN and TGF-ß was also observed. The determination of the contents of superoxide dismutase, hydroxypropyltransferase and malondialdehyde in mice dorsal skin revealed that glabridin and bakuchiol not only elevated the levels of superoxide dismutase and hydroxyproline, but also reduced malondialdehyde content. Due to the limited number of shared differential metabolites exclusively within Kyoto Encyclopedia of Genes and Genomes, comprehensive pathway enrichment analysis was not feasible. CONCLUSION: This study demonstrates that glabridin and bakuchiol effectively impede photoaging and alleviate skin inflammation in mice.

TSCRE: a comprehensive database for tumor-specific cis-regulatory elements.

Cis-regulatory elements (CREs) and super cis-regulatory elements (SCREs) are non-coding DNA regions which influence the transcription of nearby genes and play critical roles in development. Dysregulated CRE and SCRE activities have been reported to alter the expression of oncogenes and tumor suppressors, thereby regulating cancer hallmarks. To address the strong need for a comprehensive catalogue of dysregulated CREs and SCREs in human cancers, we present TSCRE (http://tscre.zsqylab.com/), an open resource providing tumor-specific and cell type-specific CREs and SCREs derived from the re-analysis of publicly available histone modification profiles. Currently, TSCRE contains 1 864 941 dysregulated CREs and 68 253 dysregulated SCREs identified from 1366 human patient samples spanning 17 different cancer types and 9 histone marks. Over 95% of these elements have been validated in public resources. TSCRE offers comprehensive annotations for each element, including associated genes, expression patterns, clinical prognosis, somatic mutations, transcript factor binding sites, cancer-type specificity, and drug response. Additionally, TSCRE integrates pathway and transcript factor enrichment analyses for each study, enabling in-depth functional and mechanistic investigations. Furthermore, TSCRE provides an interactive interface for users to explore any CRE and SCRE of interest. We believe TSCRE will be a highly valuable platform for the community to discover candidate cancer biomarkers.

Targeting proteasomal deubiquitinases USP14 and UCHL5 with b-AP15 reduces 5-fluorouracil resistance in colorectal cancer cells.

5-Fluorouracil (5-FU) is the first-line treatment for colorectal cancer (CRC) patients, but the development of acquired resistance to 5-FU remains a big challenge. Deubiquitinases play a key role in the protein degradation pathway, which is involved in cancer development and chemotherapy resistance. In this study, we investigated the effects of targeted inhibition of the proteasomal deubiquitinases USP14 and UCHL5 on the development of CRC and resistance to 5-FU. By analyzing GEO datasets, we found that the mRNA expression levels of USP14 and UCHL5 in CRC tissues were significantly increased, and negatively correlated with the survival of CRC patients. Knockdown of both USP14 and UCHL5 led to increased 5-FU sensitivity in 5-FU-resistant CRC cell lines (RKO-R and HCT-15R), whereas overexpression of USP14 and UCHL5 in 5-FU-sensitive CRC cells decreased 5-FU sensitivity. B-AP15, a specific inhibitor of USP14 and UCHL5, (1-5 µM) dose-dependently inhibited the viability of RKO, RKO-R, HCT-15, and HCT-15R cells. Furthermore, treatment with b-AP15 reduced the malignant phenotype of CRC cells including cell proliferation and migration, and induced cell death in both 5-FU-sensitive and 5-FU-resistant CRC cells by impairing proteasome function and increasing reactive oxygen species (ROS) production. In addition, b-AP15 inhibited the activation of NF-κB pathway, suppressing cell proliferation. In 5-FU-sensitive and 5-FU-resistant CRC xenografts nude mice, administration of b-AP15 (8 mg·kg-1·d-1, intraperitoneal injection) effectively suppressed the growth of both types of tumors. These results demonstrate that USP14 and UCHL5 play an important role in the development of CRC and resistance to 5-FU. Targeting USP14 and UCHL5 with b-AP15 may represent a promising therapeutic strategy for the treatment of CRC.

Piperlongumine overcomes imatinib resistance by inducing proteasome inhibition in chronic myelogenous leukemia cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper longum L., an herbal medicine used in India and other Asian countries, is prescribed routinely for a range of diseases, including tumor. Piperlongumine, a natural product isolated from Piper longum L., has received widespread attention due to its various pharmacological activities, such as anti-inflammatory, antimicrobial, and antitumor effects. AIM OF THE STUDY: Chronic myelogenous leukemia (CML) is a hematopoietic disease caused by Bcr-Abl fusion gene, with an incidence of 15% in adult leukemias. Targeting Bcr-Abl by imatinib provides a successful treatment approach for CML. However, imatinib resistance is an inevitable issue for CML treatment. In particular, T315I mutant is the most stubborn of the Bcr-Abl point mutants associated with imatinib resistance. Therefore, it is urgent to find an alternative approach to conquer imatinib resistance. This study investigated the role of a natural product piperlongumine in overcoming imatinib resistance in CML. MATERIALS AND METHODS: Cell viability and apoptosis were evaluated by MTS assay and Annexin V/propidium iodide counterstaining assay, respectively. Levels of intracellular signaling proteins were assessed by Western blots. Mitochondrial membrane potential was reflected by the fluorescence intensity of rhodamine-123. The function of proteasome was detected using 20S proteasomal activity assay, proteasomal deubiquitinase activity assay, and deubiquitinase active-site-directed labeling. The antitumor effects of piperlongumine were assessed with mice xenografts. RESULTS: We demonstrate that (i) Piperlongumine inhibits proteasome function by targeting 20S proteasomal peptidases and 19S proteasomal deubiquitinases (USP14 and UCHL5) in Bcr-Abl-WT and Bcr-Abl-T315I CML cells; (ii) Piperlongumine inhibits the cell viability of CML cell lines and primary CML cells; (iii) Proteasome inhibition by piperlongumine leads to cell apoptosis and downregulation of Bcr-Abl; (iv) Piperlongumine suppresses the tumor growth of CML xenografts. CONCLUSIONS: These results support that blockade of proteasome activity by piperlongumine provides a new therapeutic strategy for treating imatinib-resistant CML.

Inhibition of proteasomal deubiquitinases USP14 and UCHL5 overcomes tyrosine kinase inhibitor resistance in chronic myeloid leukaemia.

BACKGROUND: Chronic myeloid leukaemia (CML) is a haematological cancer featured by the presence of BCR-ABL fusion protein with abnormal tyrosine kinase activation. Classical tyrosine kinase inhibitor (TKI)-based therapies are available to patients with CML. However, acquired resistance to TKI has been a challenging obstacle, especially stubborn T315I mutation is the most common cause. Therefore, it is especially urgent to find more effective targets to overcome TKI resistance induced by BCR-ABLT315I . Proteasomal deubiquitinases (USP14 and UCHL5) have fundamental roles in the ubiquitin-proteasome system and possess multiple functions during cancer progression. METHODS: The human peripheral blood mononuclear cells were collected to measure the mRNA expression of USP14 and UCHL5, as well as to detect the toxicity effect of b-AP15. We explored the effect of b-AP15 on the activity of proteasomal deubiquitinases. We detected the effects of b-AP15 on BCR-ABLWT and BCR-ABLT315I CML cells in vitro and in the subcutaneous tumour model. We knocked down USP14 and/or UCHL5 by shRNA to explore whether these proteasomal deubiquitinases are required for cell proliferation of CML. RESULTS: In this study, we found that increased expression of the proteasomal deubiquitinase USP14 and UCHL5 in primary cancer cells from CML patients compared to healthy donors. b-AP15, an inhibitor of USP14 and UCHL5, exhibited potent tumour-killing activity in BCR-ABLWT and BCR-ABLT315I CML cell lines, as well as in CML xenografts and primary CML cells. Mechanically, pharmacological or genetic inhibition of USP14 and UCHL5 induced cell apoptosis and decreased the protein level of BCR-ABL in CML cells expressing BCR-ABLWT and BCR-ABLT315I . Moreover, b-AP15 synergistically enhanced the cytotoxic effect caused by TKI imatinib in BCR-ABLWT and BCR-ABLT315I CML cells. CONCLUSION: Collectively, our results demonstrate targeting USP14 and UCHL5 as a potential strategy for combating TKI resistance in CML.