Antileukemic effect of caffeic acid 3,4-dihydroxyphenetyl ester. Evidences for its mechanisms of action

A comprehensive review on the chemical constituents, sesquiterpenoid biosynthesis and biological activities of Sarcandra glabra

Sarcandra glabra (Thunb.) Nakai is a perennial evergreen herb categorised within the Sarcandra Gardner genus under the Chloranthaceae family. Indigenous to tropical and subtropical regions of East Asia and India, this species is extensively distributed across China, particularly in the southern regions (Sichuan, Yunnan, and Jiangxi). In addition to its high ornamental value, S. glabra has a rich history of use in traditional Chinese medicine, evident through its empirical prescriptions for various ailments like pneumonia, dysentery, fractures, bruises, numbness, amenorrhea, rheumatism, and other diseases. Besides, modern pharmacological studies have revealed various biological activities, such as antitumour, anti-bacterial, anti-viral anti-inflammatory and immunomodulatory effects. The diverse chemical constituents of S. glabra have fascinated natural product researchers since the 1900s. To date, over 400 compounds including terpenoids, coumarins, lignans, flavonoids, sterols, anthraquinones, organic acids, and organic esters have been isolated and characterised, some featuring unprecedented structures. This review comprehensively examines the current understanding of S. glabra's phytochemistry and pharmacology, with emphasis on the chemistry and biosynthesis of its unique chemotaxonomic marker, the lindenane-type sesquiterpenoids.

Structure and function of the highly homologous deubiquitinases ubiquitin specific peptidase 25 and 28: Insights into their pathophysiological and therapeutic roles

Deubiquitination is the reverse process of ubiquitination, an important protein post-translational modification. Deubiquitination is assisted by deubiquitinating enzymes (DUBs), which catalyze the hydrolysis and removal of ubiquitin chains from targeted proteins and play an important role in regulating protein stability, cell signaling transduction, and programmed cell death. Ubiquitin-specific peptidases 25 and 28 (USP25 and USP28), important members of the USP subfamily of DUBs, are highly homologous, strictly regulated, and closely associated with various diseases, such as cancer and neurodegenerative diseases. Recently, the development of inhibitors targeting USP25 and USP28 for disease treatment has garnered extreme attention. Several non-selective and selective inhibitors have shown potential inhibitory effects. However, the specificity, potency, and action mechanism of these inhibitors remain to be further improved and clarified. Herein, we summarize the structure, regulation, emerging physiological roles, and target inhibition of USP25 and USP28 to provide a basis for the development of highly potent and specific inhibitors for the treatment of diseases, such as colorectal cancer, breast cancer and so on.

Unraveling the therapeutic potential of natural products in the prevention and treatment of leukemia

Leukemia is a heterogeneous group of hematological malignancies distinguished by differentiation blockage and uncontrolled proliferation of myeloid or lymphoid progenitor cells in the bone marrow (BM) and peripheral blood (PB). There are various types of leukemia in which intensive chemotherapy regimens or hematopoietic stem cell transplantation (HSCT) are now the most common treatments associated with severe side effects and multi-drug resistance in leukemia cells. Therefore, it is crucial to develop novel therapeutic approaches with adequate therapeutic efficacy and selectively eliminate leukemic cells to improve the consequences of leukemia. Medicinal plants have been utilized for ages to treat multiple disorders due to their diverse bioactive compounds. Plant-derived products have been used as therapeutic medication to prevent and treat many types of cancer. Over the last two decades, 50 % of all anticancer drugs approved worldwide are from natural products and their derivatives. Therefore this study aims to review natural products such as polyphenols, alkaloids, terpenoids, nitrogen-containing, and organosulfur compounds as antileukemic agents. Current investigations have identified natural products efficiently destroy leukemia cells through diverse mechanisms of action by inhibiting proliferation, reactive oxygen species production, inducing cell cycle arrest, and apoptosis in both in vitro, in vivo, and clinical studies. Current investigations have identified natural products as suitable promising chemotherapeutic and chemopreventive agents. It played an essential role in drug development and emerged as a possible source of biologically active metabolites for therapeutic interventions, especially in leukemia. DATA AVAILABILITY: Data will be made available on request.

Ubiquitin-specific protease 28: the decipherment of its dual roles in cancer development

As significant posttranslational modifications, ubiquitination and deubiquitination, whose balance is modulated by ubiquitin-conjugating enzymes and deubiquitinating enzymes (DUBs), can regulate many biological processes, such as controlling cell cycle progression, signal transduction and transcriptional regulation. Belonging to DUBs, ubiquitin-specific protease 28 (USP28) plays an essential role in turning over ubiquitination and then contributing to the stabilization of quantities of substrates, including several cancer-related proteins. In previous studies, USP28 has been demonstrated to participate in the progression of various cancers. Nevertheless, several reports have recently shown that in addition to promoting cancers, USP28 can also play an oncostatic role in some cancers. In this review, we summarize the correlation between USP28 and tumor behaviors. We initially give a brief introduction of the structure and related biological functions of USP28, and we then introduce some concrete substrates of USP28 and the underlying molecular mechanisms. In addition, the regulation of the actions and expression of USP28 is also discussed. Moreover, we concentrate on the impacts of USP28 on diverse hallmarks of cancer and discuss whether USP28 can accelerate or inhibit tumor progression. Furthermore, clinical relevance, including impacting clinical prognosis, influencing therapy resistance and being the therapy target in some cancers, is depicted systematically. Thus, assistance may be given to future experimental designs by the information provided here, and the potential of targeting USP28 for cancer therapy is emphasized.

Long non‑coding RNA CTBP1‑AS2 upregulates USP22 to promote pancreatic carcinoma progression by sponging miR‑141‑3p

Long non-coding RNAs (lncRNAs) feature prominently in pancreatic carcinoma progression. The present study aimed to clarify the biological functions, clinical significance and underlying mechanism of lncRNA CTBP1 antisense RNA 2 (CTBP1-AS2) in pancreatic carcinoma. Reverse transcription-quantitative PCR was performed to assess the expression levels of CTBP1-AS2, microRNA (miR)-141-3p and ubiquitin-specific protease 22 (USP22) mRNA in pancreatic carcinoma tissues and cell lines. Western blotting was used to examine USP22 protein expression in pancreatic carcinoma cell lines. Loss-of-function experiments were used to analyze the regulatory effects of CTBP1-AS2 on proliferation, apoptosis, migration and invasion of pancreatic carcinoma cells. Dual-luciferase reporter assay was used to examine the binding relationship between CTBP1-AS2 and miR-141-3p, as well as between miR-141-3p and USP22. It was demonstrated that CTBP1-AS2 expression was markedly increased in pancreatic carcinoma tissues and cell lines. High CTBP1-AS2 expression was associated with advanced clinical stage and lymph node metastasis of patients. Functional experiments confirmed that knocking down CTBP1-AS2 significantly inhibited pancreatic carcinoma cell proliferation, migration and invasion, and promoted cell apoptosis. In terms of mechanism, it was found that CTBP1-AS2 adsorbed miR-141-3p as a molecular sponge to upregulate the expression level of USP22. In conclusion, lncRNA CTBP1-AS2 may be involved in pancreatic carcinoma progression by regulating miR-141-3p and USP22 expressions; in addition, CTBP1-AS2 may be a diagnostic biomarker and treatment target for pancreatic carcinoma.

Uvangoletin, extracted from Sarcandra glabra, exerts anticancer activity by inducing autophagy and apoptosis and inhibiting invasion and migration on hepatocellular carcinoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Uvangoletin is a dihydrochalcone extracted from the traditional Chinese medicinal plant Sarcandra glabra. Previous research has showed that uvangoletin could induce leukemia cell death. However, the anticancer effect of uvangoletin on hepatocellular carcinoma (HCC) has not been clarified.

AIM OF THE STUDY

This study aimed to investigate the anti-cancer effects of uvangoletin on HCC and to explore its underlying mechanisms.

MATERIALS AND METHODS

We measured the anticancer activities of uvangoletin both in vitro and in vivo by MTT assay and HepG2 xenograft model. The effects of uvangoletin on apoptosis, autophagy, migration and invasion were also determined. Apoptosis was evaluated by flow cytometry method. Autophagy was assessed by immunofluorescence assay. Cell migration and invasion ability were validated by wound healing assay and cultrex® 96 well cell migration/invasion assay. The expression level of relevant proteins and pathways were examined by western blot.

RESULTS

The results of MTT assay and HepG2 xenograft model showed that uvangoletin could inhibit HCC cells proliferation in vitro and in vivo. Uvangoletin could induce HepG2 cell apoptosis as evidence by the increased expression of cleaved caspase 3, caspase 8 and Bax while decreased Bcl-2 expression. Wound healing assay and transwell assay showed that uvangoletin inhibited HepG2 cells migration and invasion and reduced vimentin, MMP9, MMP2 expression. Uvangoletin also promoted autophagy in HepG2 cells as confirmed by the accumulation of GFP-LC3 puncta. Autophagy inhibitors like 3-MA or CQ could suppress uvangoletin-induced apoptosis. Importantly, uvangoletin-induced anti-EMT effect was also attenuated after autophagy inhibitors added in. Mechanistically, the expressions of p-JNK, p-ERK, p-p38, p-AKT, p-p70S6k and p-mTOR were significantly decreased after uvangoletin treatment.

CONCLUSION

Our results showed that uvangoletin could induce apoptotic and autophagic cell death, inhibit cell proliferation and metastasis on HepG2 cells through Akt/mTOR, MAPK and TGFβ/Smad2 signal pathways.