Polydopamine-Based Resveratrol-Hyaluronidase Nanomedicine Inhibited Pancreatic Cancer Cell Invasive Phenotype in Hyaluronic Acid Enrichment Tumor Sphere Model

The dense storm microenvironment formed by an excessively cross-linked extracellular matrix, such as hyaluronic acid and collagens, serves as a major barrier that prevents drugs from reaching the deeper tumor. Current traditional two-dimensional (2D) cultures are not capable of modeling this drug delivery barrier in vitro. Thus, tumor spheroids have become increasingly important in cancer research due to their three-dimensional structure. Currently, various methods have been developed to construct tumor spheroids. However, there are still challenges, such as lengthy construction time, complex composition of added growth factors, and high cultivation costs. To address this technical bottleneck, our study combined the GelMA hydrogel system to develop a rapid and high-yield method for tumor spheroids generation. Additionally, we proposed an evaluation scheme to assess the effects of drugs on tumor spheroids. Building on the hyaluronic acid-rich pathological tumor microenvironment, we constructed a resveratrol-loaded nano-drug delivery system with tumor stroma modulation capability and used a three-dimensional (3D) tumor sphere model to simulate in vivo tumor conditions. This process was utilized to completely evaluate the ability of the nano-drug delivery system to enhance the deep penetration of resveratrol in the tumor microenvironment, providing new insights into future oncology drug screening, efficacy assessment, and drug delivery methods.

Anticancer sensitivity and biological aspect of 5-fluorouracil-resistant human colorectal cancer HCT116 cells in three-dimensional culture under high- and low-glucose conditions

5-Fluorouracil (5-FU) is a commonly used anticancer drug for colorectal cancer (CRC). Therefore, it is crucial to elucidate the mechanisms that contribute to 5-FU resistance. We established an acquired 5-FU resistant cell line, HCT116RF10, derived from CRC cells and investigated its energy metabolism as well as the underlying mechanism of 5-FU resistance. We examined the sensitivity to 5-FU and the formation of tumor spheres in parental HCT116 cells and 5-FU-resistant HCT116RF10 cells under 3D culture conditions at high-glucose (HG 25 mM) and low-glucose (LG 5.5 mM) concentrations. These results suggested that the tumor spheres of parental HCT116 cells displayed higher sensitivity to 5-FU under LG conditions than under HG conditions. HCT116RF10 tumor spheres exhibited comparable sensitivity to 5-FU under HG and LG conditions. Furthermore, under HG conditions, there was a marked decrease in extracellular lactate in the HCT116RF10 tumor sphere compared to that in the LG tumor sphere. Similarly, HCT116 tumor spheres showed decreased extracellular lactate levels under LG conditions compared to those grown under HG conditions. Moreover, the evidence reveals that the tumor spheres of HCT116RF10 and HCT116 cells exhibit disparate dependencies on energy metabolism, glycolysis, and mitochondrial respiration under both HG and LG conditions. These results have important clinical implications for overcoming 5-FU resistance and enhancing antitumor treatment strategies.

Pleurotus highking mushrooms potentiate antiproliferative and antimigratory activity against triple-negative breast cancer cells by suppressing Akt signaling

In this study, we evaluated the antiproliferative and antimetastatic effects of the Pleurotus highking mushroom on the human triple-negative breast cancer cell lines MDA-MB-231 and HCC-1937 and attempted to elucidate the underlying molecular mechanisms. The antiproliferative effects of P. highking purified fraction-III (PEF-III) were investigated using colony formation and MTS assays. The antimigratory effects of PEF-III were determined by wound healing, transwell migration, and matrigel cell invasion assays. The protein expression levels were evaluated using Western blot analysis. The effect of PEF-III on tumor-sphere formation was examined in a 3D sphere-forming medium, and the mRNA expressions of proliferation- and migration-related genes in the cells from the tumor spheres were determined using RT-qPCR. PEF-III treatment caused a potent and concentration-dependent decrease in the numbers of colonies and viable cells. It also remarkably suppressed the migratory ability of the cells. Mechanistically, PEF-III treatment reduced the expression of pAkt, matrix metallopeptidase-9 (MMP-9), and vimentin. Furthermore, PEF-III reduced the number and size of the tumor spheres in the 3D culture system. It also significantly reduced the mRNA expression of Ki-67, MMP-9, and vimentin in the PEF-III-treated tumor-sphere cells. PEF-III exerted promising antiproliferative and antimigratory effects in triple-negative breast cancer cell lines by suppressing Akt signaling. Therefore, P. highking mushrooms may be considered a potential source for the development of potent anticancer drug(s) for the treatment of breast cancer.

Defined Mathematical Relationships Among Cancer Cells Suggest Modular Growth in Tumor Progression and Highlight Developmental Features Consistent With a Para-Embryonic Nature of Cancer

Several similarities between the embryo development and the cancer process suggest the para-embryonic nature of tumors. Starting from an initial cancer stem cell (i-CSC) as a para-embryonic stem cell (p-ESC), a hierarchic sequence of CSCs (CSC1s, CSC2s, CSC3s) and non-CSCs [cancer progenitor cells (CPCs), cancer differentiated cells (CDCs)] would be generated, mimicking an ectopic rudimentary ontogenesis. Such a proposed heterogeneous cell hierarchy within the tumor structure would suggest a tumor growth model consistent with experimental data reported for mammary tumors. By tabulating the theoretical data according to this model, it is possible to identify defined mathematical relationships between cancer cells (CSCs and non-CSCs) that are surprisingly similar to experimental data. Moreover, starting from this model, it is possible to speculate that, during progression, tumor growth would occur in a modular way that recalls the propagation of tumor spheres in vitro. All these considerations favor a comparison among normal blastocysts (as in vitro embryos), initial avascular tumors (as in vivo abnormal blastocysts) and tumor spheres (as in vitro abnormal blastocysts). In conclusion, this work provides further support for the para-embryonic nature of the cancer process, as recently theorized.

Pleurotus highking Mushroom Induces Apoptosis by Altering the Balance of Proapoptotic and Antiapoptotic Genes in Breast Cancer Cells and Inhibits Tumor Sphere Formation

Background and objectives: Mushrooms that have medicinal properties are part of many traditional diets. The aim of the present study was to use the human breast cancer cell line MCF-7 to investigate the anticancer activity of Pleurotus highking mushroom purified extract fraction-III (PEF-III) and to elucidate the possible mechanism of that activity. Materials and Methods: The effects of PEF-III on cell proliferation and viability were evaluated by a colony formation assay and an MTT assay, respectively. Cell morphological changes, annexin-V phycoerythrin and propidium iodide (PI) staining, DNA fragmentation, and caspase 3/7 activity assays were performed to determine the induction of apoptosis by PEF-III. The genes responsible for regulation of apoptosis were analyzed by means of Western blot analysis. In vitro tumor sphere formation assay was performed using a 3D sphere culture system. Results: PEF-III significantly reduced the proliferation and viability of MCF-7 cells. Cell shrinkage and rounding, and annexin-V phycoerythrin and PI staining followed by flow cytometry indicated that the cell death was due to apoptosis. Additionally, a laddering DNA pattern and increased levels of caspase-3/7 enzyme also corroborated the notion of apoptosis-mediated cell death. This incidence was further confirmed by upregulation of proapoptotic genes (p53 and its target gene, Bax) and downregulation of the expression of an antiapoptotic gene (Bcl-2). PEF-III also reduced the size and number of the tumor spheres in 3D culture conditions. Conclusions: The anticancer activity of PEF-III is due to induction of apoptosis by a shift in the balance of proapoptotic and antiapoptotic genes. Therefore, the findings of the present study may open a path to exploring potential drug candidates from the P.highking mushroom for combating breast cancer.

IL-8 regulates the stemness properties of cancer stem cells in the small-cell lung cancer cell line H446

PURPOSE

Cancer stem cells (CSCs) are a small population of cancer cells located within a tumor that are highly tumorigenic, capable of tumor initiation, and resistant to cancer therapies. We identified the potential genes involved in regulating stemness properties and investigated the mechanisms in small-cell lung cancer (SCLC).

MATERIALS AND METHODS

Whole transcriptome sequencing technology was used to screen the potential genes involved in regulating stemness properties from SCLC-SCs (uPAR+) and differentiated cells (uPAR-) in the H446 cell line. The selected genes were validated by quantitative reverse transcription PCR and ELISAs. The effect of IL-8 on stemness of sphere-forming cells was determined through tumor sphere formation, wound healing migration, and in vivo tumorigenesis assays.

RESULTS

In our study, uPAR+ and uPAR- cells showed different gene expression profiles. IL-8 was upregulated in SCLC sphere-forming cells. Blocking IL-8 expression with siRNA led to loss of stemness, including the self-renewal capability, migration, expression of stemness-related genes, and in vivo tumorigenicity, in sphere-forming cells. Consistently, exogenously added IL-8 enhanced stemness properties in parental cells.

CONCLUSION

IL-8 was upregulated in SCLC sphere-forming cells, and critical for the acquisition and/or maintenance of the stemness features in the SCLC cell line H446. Our results suggest that blocking IL-8 signaling may provide a novel therapeutic approach for targeting SCLC-SCs and improve treatment and outcomes in SCLC.

Neurocan, an extracellular chondroitin sulfate proteoglycan, stimulates neuroblastoma cells to promote malignant phenotypes

Neurocan (NCAN), a secreted chondroitin sulfate proteoglycan, is one of the major inhibitory molecules for axon regeneration in nervous injury. However, its role in cancer is not clear. Here we observed that high NCAN expression was closely associated with the unfavorable outcome of neuroblastoma (NB). NCAN was also highly and ubiquitously expressed in the early lesions and terminal tumor of TH-MYCN mice, a NB model. Interestingly, exogenous NCAN (i.e., overexpression, recombinant protein and conditioned medium) transformed adherent NB cells into spheres whose malignancies in vitro (anchorage-independent growth and chemoresistance) and in vivo (xenograft tumor growth) were potentiated. Both chondroitin sulfate sugar chains and NCAN's core protein were essential for the sphere formation. The CSG3 domain was essential in the moiety of NCAN. Our comprehensive microarray analysis and RT-qPCR of mRNA expression suggested that NCAN treatment promoted cell division, and urged cells to undifferentiated state. The knockdown of NCAN in tumor sphere cells cultured from TH-MYCN mice resulted in growth suppression in vitro and in vivo. Our findings suggest that NCAN, which stimulates NB cells to promote malignant phenotypes, is an extracellular molecule providing a growth advantage to cancer cells.

Single cell dual adherent-suspension co-culture micro-environment for studying tumor-stromal interactions with functionally selected cancer stem-like cells

Considerable evidence suggests that cancer stem-like cells (CSCs) are critical in tumor pathogenesis, but their rarity and transience has led to much controversy about their exact nature. Although CSCs can be functionally identified using dish-based tumorsphere assays, it is difficult to handle and monitor single cells in dish-based approaches; single cell-based microfluidic approaches offer better control and reliable single cell derived sphere formation. However, like normal stem cells, CSCs are heavily regulated by their microenvironment, requiring tumor-stromal interactions for tumorigenic and proliferative behaviors. To enable single cell derived tumorsphere formation within a stromal microenvironment, we present a dual adherent/suspension co-culture device, which combines a suspension environment for single-cell tumorsphere assays and an adherent environment for co-culturing stromal cells in close proximity by selectively patterning polyHEMA in indented microwells. By minimizing dead volume and improving cell capture efficiency, the presented platform allows for the use of small numbers of cells (<100 cells). As a proof of concept, we co-cultured single T47D (breast cancer) cells and primary cancer associated fibroblasts (CAF) on-chip for 14 days to monitor sphere formation and growth. Compared to mono-culture, co-cultured T47D have higher tumorigenic potential (sphere formation rate) and proliferation rates (larger sphere size). Furthermore, 96-multiplexed single-cell transcriptome analyses were performed to compare the gene expression of co-cultured and mono-cultured T47D cells. Phenotypic changes observed in co-culture correlated with expression changes in genes associated with proliferation, apoptotic suppression, tumorigenicity and even epithelial-to-mesechymal transition. Combining the presented platform with single cell transcriptome analysis, we successfully identified functional CSCs and investigated the phenotypic and transcriptome effects induced by tumor-stromal interactions.

Study on like-stem characteristics of tumor sphere cells in human gastric cancer line HGC-27

Stem-like cancer cells are called cancer stem cells (CSCs) or tumor stem cells (TSCs). Methods for sorting CSCs are mainly based on the marker (CD133+/CD44+) or side population cells. However, CD133+/CD44+ cells or side population cells are very rare or even undetectable. In the present study, the tumor sphere of human gastric cancer (HGC) cell line HGC-27 was used for CSCs enrichment, and stem-like characteristics were verified by Hoechst 33342 staining technology, cell growth rate assays, sphere differentiation assay, clone formation, chemotherapy resistance study and tumor formation in an animal model. Our results demonstrated that the tumor sphere cells of HGC-27 cell line could be used to enrich CSCs, which may contribute to human gastric cancer stem cell biology research.