The tumor suppressor p53 can promote collective cellular migration

Energy Metabolism Behavior and Response to Microenvironmental Factors of the Experimental Cancer Cell Models Differ from that of Actual Human Tumors

Analysis of the biochemical differences in the energy metabolism among bi-dimensional (2D) and tri-dimensional (3D) cultured cancer cell models and actual human tumors was undertaken. In 2D cancer cells, the oxidative phosphorylation (OxPhos) fluxes range is 2.5-19 nmol O2/min/mg cellular protein. Hypoxia drastically decreased OxPhos flux by 2-3 times in 2D models, similar to what occurs in mature multicellular tumor spheroids (MCTS), a representative 3D cancer cell model. However, mitochondrial protein contents and enzyme activities were significantly different between both models. Moreover, glycolytic fluxes were also significantly different between 2D and MCTS. The glycolytic flux range in 2D models is 1-34 nmol lactate/min/mg cellular protein, whereas in MCTS the range of glycolysis fluxes is 60-80 nmol lactate/min/mg cellular. In addition, sensitivity to anticancer canonical and metabolic drugs was greater in MCTS than in 2D. Actual solid human tumor samples show lower (1.6-4.5 times) OxPhos fluxes compared to normoxic 2D cancer cell cultures. These observations indicate that tridimensional organization provides a unique microenvironment affecting tumor physiology, which has not been so far faithfully reproduced by the 2D environment. Thus, the analysis of the resemblances and differences among cancer cell models undertaken in the present study raises caution on the interpretation of results derived from 2D cultured cancer cells when they are extended to clinical settings. It also raises awareness about detecting which biological and environmental factors are missing in 2D and 3D cancer cell models to be able to reproduce the actual human tumor behavior.

PhaseFIT: live-organoid phase-fluorescent image transformation via generative AI

Organoid models have provided a powerful platform for mechanistic investigations into fundamental biological processes involved in the development and function of organs. Despite the potential for image-based phenotypic quantification of organoids, their complex 3D structure, and the time-consuming and labor-intensive nature of immunofluorescent staining present significant challenges. In this work, we developed a virtual painting system, PhaseFIT (phase-fluorescent image transformation) utilizing customized and morphologically rich 2.5D intestinal organoids, which generate virtual fluorescent images for phenotypic quantification via accessible and low-cost organoid phase images. This system is driven by a novel segmentation-informed deep generative model that specializes in segmenting overlap and proximity between objects. The model enables an annotation-free digital transformation from phase-contrast to multi-channel fluorescent images. The virtual painting results of nuclei, secretory cell markers, and stem cells demonstrate that PhaseFIT outperforms the existing deep learning-based stain transformation models by generating fine-grained visual content. We further validated the efficiency and accuracy of PhaseFIT to quantify the impacts of three compounds on crypt formation, cell population, and cell stemness. PhaseFIT is the first deep learning-enabled virtual painting system focused on live organoids, enabling large-scale, informative, and efficient organoid phenotypic quantification. PhaseFIT would enable the use of organoids in high-throughput drug screening applications.

Diverse activity of miR-150 in Tumor development: shedding light on the potential mechanisms

There is a growing interest to understand the role and mechanism of action of microRNAs (miRNAs) in cancer. The miRNAs are defined as short non-coding RNAs (18-22nt) that regulate fundamental cellular processes through mRNA targeting in multicellular organisms. The miR-150 is one of the miRNAs that have a crucial role during tumor cell progression and metastasis. Based on accumulated evidence, miR-150 acts as a double-edged sword in malignant cells, leading to either tumor-suppressive or oncogenic function. An overview of miR-150 function and interactions with regulatory and signaling pathways helps to elucidate these inconsistent effects in metastatic cells. Aberrant levels of miR-150 are detectable in metastatic cells that are closely related to cancer cell migration, invasion, and angiogenesis. The ability of miR-150 in regulating of epithelial-mesenchymal transition (EMT) process, a critical stage in tumor cell migration and metastasis, has been highlighted. Depending on the cancer cells type and gene expression profile, levels of miR-150 and potential target genes in the fundamental cellular process can be different. Interaction between miR-150 and other non-coding RNAs, such as long non-coding RNAs and circular RNAs, can have a profound effect on the behavior of metastatic cells. MiR-150 plays a significant role in cancer metastasis and may be a potential therapeutic target for preventing or treating metastatic cancer.

Chenodeoxycholic acid inhibits lung adenocarcinoma progression via the integrin α5β1/FAK/p53 signaling pathway

BACKGROUND

Lung cancer is the leading cause of cancer-associated death worldwide and is classified into non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). NSCLC accounts for approximately 80%-85% of all lung cancer cases. Chenodeoxycholic acid (CDCA), a primary bile acid, has been reported to inhibit carcinoma cell proliferation. Here, we aimed to determine the effects and mechanism of action of CDCA against lung adenocarcinoma (LUAD).

METHODS

Western blotting and quantitative real-time polymerase chain reaction were used to evaluate the protein and mRNA expression levels in LUAD cell lines, respectively. Cell Counting Kit-8 and clone formation assays were performed to evaluate the proliferation ability of different cell types in vitro. Tumor cell motility was evaluated using Transwell assays. The transcriptional profile of A549 cells treated with CDCA was determined through RNA sequencing analysis. A xenograft model was established to evaluate the effects of CDCA on LUAD progression in vivo.

RESULTS

CDCA inhibited LUAD cell proliferation, migration, and invasion. Furthermore, it promoted apoptosis in LUAD cells. Mechanistically, CDCA inhibited the integrin α5β1 signaling pathway in LUAD cells by inhibiting the expression of the α5 and β1 subunits of integrin and phosphorylated FAK. Moreover, CDCA induced an increase in the levels of p53, a downstream gene of the integrin α5β1/FAK pathway. In addition, CDCA significantly decreased tumor volume in mice without inducing significant toxicity.

CONCLUSIONS

Our findings indicate that CDCA attenuates LUAD pathogenesis in vitro and in vivo via the integrin α5β1/FAK/p53 axis.

Bridging Tumorigenesis and Therapy Resistance With a Non-Darwinian and Non-Lamarckian Mechanism of Adaptive Evolution

Although neo-Darwinian (and less often Lamarckian) dynamics are regularly invoked to interpret cancer's multifarious molecular profiles, they shine little light on how tumorigenesis unfolds and often fail to fully capture the frequency and breadth of resistance mechanisms. This uncertainty frames one of the most problematic gaps between science and practice in modern times. Here, we offer a theory of adaptive cancer evolution, which builds on a molecular mechanism that lies outside neo-Darwinian and Lamarckian schemes. This mechanism coherently integrates non-genetic and genetic changes, ecological and evolutionary time scales, and shifts the spotlight away from positive selection towards purifying selection, genetic drift, and the creative-disruptive power of environmental change. The surprisingly simple use-it or lose-it rationale of the proposed theory can help predict molecular dynamics during tumorigenesis. It also provides simple rules of thumb that should help improve therapeutic approaches in cancer.

A theoretical model of collective cell polarization and alignment

Collective cell polarization and alignment play important roles in tissue morphogenesis, wound healing and cancer metastasis. How cells sense the direction and position in these processes, however, has not been fully understood. Here we construct a theoretical model based on describing cell layer as a nemato-elastic medium, by which the cell polarization, cell alignment and cell active contraction are explicitly expressed as functions of components of the nematic order parameter. To determine the order parameter we derive two sets of governing equations, one for the force equilibrium of the system, and the other for the minimization of the system's free energy including the energy of cell polarization and alignment. By solving these coupled governing equations, we can predict the effects of substrate stiffness, geometries of cell layers, external forces and myosin activity on the direction- and position-dependent cell aspect ratio and cell orientation. Moreover, the axisymmetric problem with cells on a ring-like pattern is solved analytically, and the analytical solution for cell aspect ratio are governed by parameter groups which include the stiffness of the cell and the substrate, the strength of myosin activity and the external forces. Our predictions of the cell aspect ratio and orientation are generally comparable to experimental observations. These results show that the pattern of cell polarization is determined by the anisotropic degree of active contractile stress, and suggest a stress-driven polarization mechanism that enables cells to sense their spatial positions to develop direction- and position-dependent behavior. This, in turn, sheds light on the ways to control pattern formation in tissue engineering for potential biomedical applications.

Unjamming and collective migration in MCF10A breast cancer cell lines

Each cell comprising an intact, healthy, confluent epithelial layer ordinarily remains sedentary, firmly adherent to and caged by its neighbors, and thus defines an elemental constituent of a solid-like cellular collective [1,2]. After malignant transformation, however, the cellular collective can become fluid-like and migratory, as evidenced by collective motions that arise in characteristic swirls, strands, ducts, sheets, or clusters [3,4]. To transition from a solid-like to a fluid-like phase and thereafter to migrate collectively, it has been recently argued that cells comprising the disordered but confluent epithelial collective can undergo changes of cell shape so as to overcome geometric constraints attributable to the newly discovered phenomenon of cell jamming and the associated unjamming transition (UJT) [1,2,5-9]. Relevance of the jamming concept to carcinoma cells lines of graded degrees of invasive potential has never been investigated, however. Using classical in vitro cultures of six breast cancer model systems, here we investigate structural and dynamical signatures of cell jamming, and the relationship between them [1,2,10,11]. In order of roughly increasing invasive potential as previously reported, model systems examined included MCF10A, MCF10A.Vector; MCF10A.14-3-3ζ; MCF10.ErbB2, MCF10AT; and MCF10CA1a [12-15]. Migratory speed depended on the particular cell line. Unsurprisingly, for example, the MCF10CA1a cell line exhibited much faster migratory speed relative to the others. But unexpectedly, across different cell lines higher speeds were associated with enhanced size of cooperative cell packs in a manner reminiscent of a peloton [9]. Nevertheless, within each of the cell lines evaluated, cell shape and shape variability from cell-to-cell conformed with predicted structural signatures of cell layer unjamming [1]. Moreover, both structure and migratory dynamics were compatible with previous theoretical descriptions of the cell jamming mechanism [2,10,11,16,17]. As such, these findings demonstrate the richness of the cell jamming mechanism, which is now seen to apply across these cancer cell lines but remains poorly understood.

Dehydrogenase/reductase SDR family member 2 silencing sensitizes an oxaliplatin‑resistant cell line to oxaliplatin by inhibiting excision repair cross‑complementing group 1 protein expression

Oxaliplatin (Oxa)-based chemotherapy is widely used as the first-line treatment for colorectal cancer (CRC). However, Oxa-resistance is common for many postoperative CRC patients. To explore drug resistance in CRC, an Oxa-resistant cell line, HCT116/Oxa, was established from parental HCT116 cells. These Oxa-resistant cells exhibited characteristics of epithelial-mesenchymal transition (EMT) and a higher migratory capacity than parental cells. Protein profiles of HCT116/Oxa and HCT116 cells were compared using a tandem mass tag-based quantitative proteomics technique. The protein dehydrogenase/reductase SDR family member 2 (DHRS2) was revealed to be highly expressed in HCT116/Oxa cells. Silencing of DHRS2 in HCT116/Oxa cells effectively restored Oxa-sensitivity by suppressing the expression of excision repair cross-complementing group 1 protein via a p53-dependent pathway, and reversed the EMT phenotype. Overall, the suppression of DHRS2 expression may be a promising strategy for the prevention of Oxa-resistance in CRC.