Procyanidins mediates antineoplastic effects against non-small cell lung cancer via the JAK2/STAT3 pathway

Targeting the key players of phenotypic plasticity in cancer cells by phytochemicals

Plasticity of phenotypic traits refers to an organism's ability to change in response to environmental stimuli. As a result, the response may alter an organism's physiological state, morphology, behavior, and phenotype. Phenotypic plasticity in cancer cells describes the considerable ability of cancer cells to transform phenotypes through non-genetic molecular signaling activities that promote therapy evasion and tumor metastasis via amplifying cancer heterogeneity. As a result of metastable phenotypic state transitions, cancer cells can tolerate chemotherapy or develop transient adaptive resistance. Therefore, new findings have paved the road in identifying factors and agents that inhibit or suppress phenotypic plasticity. It has also investigated novel multitargeted agents that may promise new effective strategies in cancer treatment. Despite the efficiency of conventional chemotherapeutic agents, drug toxicity, development of resistance, and high-cost limit their use in cancer therapy. Recent research has shown that small molecules derived from natural sources are capable of suppressing cancer by focusing on the plasticity of phenotypic responses. This systematic, comprehensive, and critical review analyzes the current state of knowledge regarding the ability of phytocompounds to target phenotypic plasticity at both preclinical and clinical levels. Current challenges/pitfalls, limitations, and future perspectives are also discussed.

Proanthocyanidins inhibited colorectal cancer stem cell characteristics through Wnt/β-catenin signaling

BACKGROUND

Cancer stem cells (CSCs) play a key role in tumor cell growth, drug resistance, recurrence, and metastasis. Proanthocyanidins (PC) is widely existed in plants and endowed with powerful antioxidant and anti-aging effects. Interestingly, recent studies have found that PC exhibits the inhibitory effect on tumor growth. However, the role of PC in CSCs of colorectal cancer (CRC) and molecular mechanism remain unclear.

METHODS

CCK-8, colony, and tumorsphere formation assay were used to evaluate cancer cell viability and stemness, respectively. Western blotting was used to detect the protein expression. Tumor xenograft experiments were employed to examine the tumorigenicity of CRC cells in nude mice.

RESULTS

PC decreased the proliferation of CRC cells (HT29 and HCT-116), and improved the sensitivity of CRC cells to oxaliplatin (L-OHP), as well as inhibited tumor growth in nude mice. Further studies showed that PC also down-regulated CSCs surface molecular and stemness transcriptional factors, while suppressed the formations of tumorspheres and cell colony in CRC. In addition, PC-impaired proteins expressions of p-GSK3β, β-catenin and DVL1-3. LiCl, an activator of the Wnt/β-catenin signaling, rescued PC-induced downregulation of CSCs markers, and reduction of tumorspheres and cell colony formation abilities in CRC cells. Furthermore, the effects of PC on inhibiting cell proliferation and enhancing L-OHP sensitivity were impaired by LiCl.

CONCLUSIONS

PC exerted an inhibitory effect on CSCs via Wnt/β-catenin in CRC, and may be a potential new class of natural drug for CRC treatment.

Oligomeric Proanthocyanidins: An Updated Review of Their Natural Sources, Synthesis, and Potentials

Oligomeric Proanthocyanidins (OPCs), as a class of compounds widely found in plants, are particularly abundant in grapes and blueberries. It is a polymer comprising many different monomers, such as catechins and epicatechins. The monomers are usually linked to each other by two types of links, A-linkages (C-O-C) and B-linkages (C-C), to form the polymers. Numerous studies have shown that compared to high polymeric procyanidins, OPCs exhibit antioxidant properties due to the presence of multiple hydroxyl groups. This review describes the molecular structure and natural source of OPCs, their general synthesis pathway in plants, their antioxidant capacity, and potential applications, especially the anti-inflammatory, anti-aging, cardiovascular disease prevention, and antineoplastic functions. Currently, OPCs have attracted much attention, being non-toxic and natural antioxidants of plant origin that scavenge free radicals from the human body. This review would provide some references for further research on the biological functions of OPCs and their application in various fields.

LncRNA CARMN inhibits cervical cancer cell growth via the miR-92a-3p/BTG2/Wnt/β-catenin axis

Long noncoding RNA (lncRNA) cardiac mesoderm enhancer-associated noncoding RNA (CARMN) is a newly discovered tumor-suppressor lncRNA in cancers. However, its role in cervical cancer (CC) remains elusive. This study was conducted to analyze the molecular mechanism of CARMN in CC cell growth and provide a novel theoretical basis for CC treatment. RT-qPCR and clinical analysis revealed that CARMN and B-cell translocation gene 2 (BTG2) were downregulated, whereas miR-92a-3p was upregulated in CC tissues and cells and their expressions were correlated with clinicopathological characteristics and prognosis. MTT assay, flow cytometry, and Transwell assays revealed that CARMN overexpression reduced proliferation, migration, and invasion and increased apoptosis rate in CC cells. Mechanically, CARMN repressed miR-92a-3p to promote BTG2 transcription. Functional rescue assays revealed that miR-92a-3p overexpression or BTG2 downregulation reversed the inhibitory role of CARMN overexpression in CC cell growth. Western blot analysis elicited that Wnt3a and β-catenin were elevated in CC cells and CARMN blocked the Wnt/β-catenin signaling pathway via the miR-92a-3p/BTG2 axis. Overall, our findings demonstrated that CARMN repressed miR-92a-3p to upregulate BTG2 transcription and then blocked the Wnt/β-catenin signaling pathway, thereby suppressing CC cell growth.

Recent Progress in Research on Mechanisms of Action of Natural Products against Alzheimer's Disease: Dietary Plant Polyphenols

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system and the most common type of dementia in the elderly. Despite years of extensive research efforts, our understanding of the etiology and pathogenesis of AD is still highly limited. Nevertheless, several hypotheses related to risk factors for AD have been proposed. Moreover, plant-derived dietary polyphenols were also shown to exert protective effects against neurodegenerative diseases such as AD. In this review, we summarize the regulatory effects of the most well-known plant-derived dietary polyphenols on several AD-related molecular mechanisms, such as amelioration of oxidative stress injury, inhibition of aberrant glial cell activation to alleviate neuroinflammation, inhibition of the generation and promotion of the clearance of toxic amyloid-β (Aβ) plaques, inhibition of cholinesterase enzyme activity, and increase in acetylcholine levels in the brain. We also discuss the issue of bioavailability and the potential for improvement in this regard. This review is expected to encourage further research on the role of natural dietary plant polyphenols in the treatment of AD.

Insights into the Mechanisms of Action of Proanthocyanidins and Anthocyanins in the Treatment of Nicotine-Induced Non-Small Cell Lung Cancer

In traditional medicine, different parts of plants, including fruits, have been used for their anti-inflammatory and anti-oxidative properties. Plant-based foods, such as fruits, seeds and vegetables, are used for therapeutic purposes due to the presence of flavonoid compounds. Proanthocyanidins (PCs) and anthocyanins (ACNs) are the major distributed flavonoid pigments in plants, which have therapeutic potential against certain chronic diseases. PCs and ACNs derived from plant-based foods and/or medicinal plants at different nontoxic concentrations have shown anti-non-small cell lung cancer (NSCLC) activity in vitro/in vivo models through inhibiting proliferation, invasion/migration, metastasis and angiogenesis and by activating apoptosis/autophagy-related mechanisms. However, the potential mechanisms by which these compounds exert efficacy against nicotine-induced NSCLC are not fully understood. Thus, this review aims to gain insights into the mechanisms of action and therapeutic potential of PCs and ACNs in nicotine-induced NSCLC.