A natural product atalantraflavone inhibits non-small cell lung cancer progression via destabilizing Twist1

Twist1 as a target for prevention of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) represents an important clinical problem requiring novel approaches for both prevention and treatment. The transcription factor, Twist-related protein 1 (Twist1), has been identified as having a key mechanistic role in the development and progression of cSCC. Studies in relevant mouse models of cSCC have shown that Twist1 regulates epithelial-mesenchymal transition (EMT) and stemness driving progression and metastasis of cSCC. In addition, further research has shown that Twist1 regulates the balance between keratinocyte proliferation and differentiation and therefore impacts earlier stages of cSCC development. Through use of keratinocyte specific Twist1 knockout models, a role for this gene in keratinocyte stem cell homeostasis has been revealed. As a transcription factor, Twist1 regulates a large number of genes both in a positive, as well as a negative manner across several interdependent pathways. Studies in keratinocyte specific knockout models have shown that Twist1 upregulates the expression of genes involved in proliferation, stemness, and EMT while downregulating the expression of genes associated with differentiation. Furthermore, a number of compounds, including naturally occurring compounds, have been identified that target Twist1 and can block its effects in cancer cells and in keratinocytes in vivo. Collectively, the current understanding of Twist1 function in cSCC development and progression suggests that it represents a potential target for prevention and treatment of cSCC.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Harmine-inspired design and synthesis of benzo[d]imidazo[2,1-b]thiazole derivatives bearing 1,3,4-oxadiazole moiety as potential tumor suppressors

Standard chemotherapy and personalized target therapies are commonly used in patients with advanced non-small cell lung cancer (NSCLC). However, multidrug resistance (MDR) and tumor metastasis lead to the decline of therapeutic efficacy, which are closely related to epithelial-mesenchymal transition (EMT). Twist1, an EMT transcription factor, plays an essential role in promoting EMT, MDR and tumor metastasis. In view of the essential role of Twist1 in the tumorigenesis of NSCLC, developing antitumor small molecules that can suppress the expression of Twist1 is of far-reaching significance for the treatment of NSCLC. A series of novel benzo[d]imidazo[2,1-b]thiazole derivatives possessing 1,3,4-oxadiazole moiety were designed based on the structure of the first-in-class Twist1 inhibitor harmine. Among the synthetic twenty-two compounds, the compound containing 2-(piperidine-1-yl) ethyl exhibited remarkable anti-proliferative activity with IC₅₀ value of 2.03 μM and 9.80 μM against A549 and H2228 cell lines superior to harmine (IC₅₀ = 17.12 μM against A549, IC₅₀ = 31.06 μM against H2228). Meanwhile, western blot assay showed that the optimal compound significantly down-regulated Twist1 protein expression in a dose-dependent manner and reduced Twist1 level better than harmine. Collectively, the promising compound was identified a potential antineoplastic lead with the ability of down-regulating Twist1 level.

Kaempferol-3-O-rutinoside, a flavone derived from Tetrastigma hemsleyanum, suppresses lung adenocarcinoma via the calcium signaling pathway

Lung cancer has been threatening human health worldwide for a long time. However, the clinic therapies remain unsatisfactory. In this study, the anti-adenocarcinoma lung cancer A549 cell line abilities of Tetrastigma hemsleyanum tuber flavonoids (THTF) were evaluated in vivo, and isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis was conducted to detect the protein alterations in THTF-treated solid tumors. The differentially expressed proteins were related to the cytoskeleton and mostly accumulated in the calcium signaling pathway. The in vitro study illustrated that 80 μg mL-1 THTF significantly suppressed cellular viability to approximately 75% of the control. Further results suggested that kaempferol-3-O-rutinoside (K3R), the major component of THTF, effectively triggered cytoskeleton collapse, mitochondrial dysfunction and consequent calcium overload to achieve apoptosis, which remained consistent with proteomic results. This study uncovers a new mechanism for THTF anti-tumor ability, and suggests THTF and K3R as promising anti-cancer agents, providing new ideas and possible strategies for future anti-lung cancer prevention and therapy.

A narrative review of the migration and invasion features of non-small cell lung cancer cells upon xenobiotic exposure: insights from in vitro studies

Lung cancer (LC) is the leading cause of cancer deaths worldwide, being non-small lung cancer (NSCLC) sub-types the most prevalent. Since most LC cases are only detected during the last stage of the disease the high mortality rate is strongly associated with metastases. For this reason, the migratory and invasive capacity of these cancer cells as well as the mechanisms involved have long been studied to uncover novel strategies to prevent metastases and improve the patients’ prognosis. This narrative review provides an overview of the main in vitro migration and invasion assays employed in NSCLC research. While several methods have been developed, experiments using conventional cell culture models prevailed, specifically the wound-healing and the transwell migration and invasion assays. Moreover, it is provided herewith a summary of the available information concerning chemical contaminants that may promote the migratory/invasive properties of NSCLC cells in vitro, shedding some light on possible LC risk factors. Most of the reported agents with pro-migration/invasion effects derive from cigarette smoking [e.g., Benzo(a)pyrene and cadmium] and air pollution. This review further presents several studies in which different dietary/plant-derived compounds demonstrated to impair migration/invasion processes in NSCLC cells in vitro. These chemicals that have been proposed as anti-migratory consisted mainly of natural bioactive substances, including polyphenols non-flavonoids, flavonoids, bibenzyls, terpenes, alkaloids, and steroids. Some of these compounds may eventually represent novel therapeutic strategies to be considered in the future to prevent metastasis formation in LC, which highlights the need for additional in vitro methodologies that more closely resemble the in vivo tumor microenvironment and cancer cell interactions. These studies along with adequate in vivo models should be further explored as proof of concept for the most promising compounds.

TRIP suppresses cell proliferation and invasion in choroidal melanoma via promoting the proteasomal degradation of Twist1

Choroidal melanoma (CM) remains the most prevalent form of intraocular malignancy, and the prognosis of affected patients is poor. While the E3 ubiquitin ligase TRAF-interacting protein (TRIP) is known to play key regulatory roles in multiple diseases, its relevance in CM remains uncertain. In the present study, we found that TRIP overexpression is sufficient to inhibit the proliferation, invasion, and epithelial-mesenchymal transition (EMT) of CM cells in vitro, whereas the opposite phenotypes are observed following TRIP knockdown. We further determined that TRIP is able to promote the K48-polyubiquitination of EMT-associated transcription factor Twist-related protein 1, thereby suppressing EMT progression. Together, our results suggest that TRIP plays an important role in regulating the progression of CM and that it may therefore be an important therapeutic target for the treatment of this disease.

Multifloroside Suppressing Proliferation and Colony Formation, Inducing S Cell Cycle Arrest, ROS Production, and Increasing MMP in Human Epidermoid Carcinoma Cell Lines A431

Multifloroside (4), together with 10-hydroxyoleoside 11-methyl ester (1), 10-hydroxyoleoside dimethyl ester (2), and 10-hydroxyligustroside (3), are all secoiridoids, which are naturally occurring compounds that possess a wide range of biological and pharmacological activities. However, the anti-cancer activity of 1–4 has not been evaluated yet. The objective of this work was to study the anti-cancer activities of 1–4 in the human epidermoid carcinoma cell lines A431 and the human non-small cell lung cancer (NSCLC) cell lines A549. The results indicate that 1–4 differ in potency in their ability to inhibit the proliferation of human A431 and A549 cells, and multifloroside (4) display the highest inhibitory activity against A431 cells. The structure-activity relationships suggest that the o-hydroxy-p-hydroxy-phenylethyl group may contribute to the anti-cancer activity against A431 cells. Multifloroside treatment can also inhibit cell colony formation, arrest the cell cycle in the S-phase, increase the levels of reactive-oxygen-species (ROS), and mitochondrial membrane potential (MMP), but it did not significantly induce cell apoptosis at low concentrations. The findings indicated that multifloroside (4) has the tendency to show selective anti-cancer effects in A431 cells, along with suppressing the colony formation, inducing S cell cycle arrest, ROS production, and increasing MMP.