Colorectal cancer stem cell-derived exosomal long intergenic noncoding RNA 01315 (LINC01315) promotes proliferation, migration, and stemness of colorectal cancer cells

The effect of long intergenic noncoding RNA 01315 (LINC01315) on colorectal cancer has widely been proved. Nevertheless, how LINC01315 functions in the stemness of colorectal cancer and whether LINC01315 exists in colorectal cancer stem-like cell-derived exosomes remain dim, which are thus investigated in this research. CD133⁺/CD44⁺ colorectal cancer stem cells were sorted and verified through flow cytometry. Exosomes derived from CD133⁺/CD44⁺ colorectal cancer stem cells were collected. The viability, proliferation, stemness and migration of CD133⁺/CD44⁺, CD133⁻/CD44⁻, and colorectal cancer cells after transfection or the co-culture with exosomes were detected by MTT, colony formation, spheroid, and wound healing assays, respectively. Expressions of LINC01315, BCL-2, Bax, cleaved caspase-3, MMP-9, E-cadherin, and vimentin in cells or exosomes were analyzed using western blot or qRT-PCR. Genes interacted with LINC01315 in colorectal cancer were predicted by bioinformatics analysis. The results showed that LINC01315 was high-expressed in CD133⁺/CD44⁺ colorectal cancer stem cells and exosomes. Compared with colorectal cancer cells, the viability, proliferation, stemness, and migration of CD133⁺/CD44⁺ cancer cells were stronger, while these of CD133⁻/CD44⁻ cancer cells were weaker. Besides, LINC01315 silencing decreased the viability, proliferation, stemness, and migration of CD133⁺/CD44⁺ cancer cells, while sh-LINC01315 inhibited the promotive effects of CD133⁺/CD44⁺ cancer cell-derived exosomes on the viability, proliferation, stemness, and migration of colorectal cancer cells. LINC01315 was also found to be correlated with DPEP1, KRT23, ASCL2, AXIN2, and DUSP4 in colorectal cancer. In conclusion, colorectal cancer stem cell-derived exosomal LINC01315 promotes the proliferation, migration, and stemness of colorectal cancer cells.

Green Synthesized Honokiol Transfersomes Relieve the Immunosuppressive and Stem-Like Cell Characteristics of the Aggressive B16F10 Melanoma

BACKGROUND

Honokiol (HK) is a natural bioactive compound with proven antineoplastic properties against melanoma. However, it shows very low bioavailability when administered orally. Alternatively, topical administration may offer a promising route. The objective of the current study was to fabricate HK transfersomes (HKTs) for topical treatment of melanoma. As an ultradeformable carrier system, transfersomes can overcome the physiological barriers to topical treatment of melanoma: the stratum corneum and the anomalous tumor microenvironment. Moreover, the immunomodulatory and stemness-regulation roles of HKTs were the main interest of this study.

METHODS

TFs were prepared using the modified scalable heating method. A three-factor, three-level Box-Behnken design was utilized for the optimization of the process and formulation variables. Intracellular uptake and cytotoxicity of HKTs were evaluated in nonactivated and stromal cell-activated B16F10 melanoma cells to investigate the influence of the complex tumor microenvironment on the efficacy of HK. Finally, ELISA and Western blot were performed to evaluate the expression levels of TGF-β and clusters of differentiation (CD47 and CD133, respectively).

RESULTS

The optimized formula exhibited a mean size of 190 nm, highly negative surface charge, high entrapment efficiency, and sustained release profile. HKTs showed potential to alleviate the immunosuppressive characteristics of B16F10 melanoma in vitro via downregulation of TGF-β signaling. In addition, HKTs reduced expression of the "do not eat me" signal - CD47. Moreover, HKTs possessed additional interesting potential to reduce the expression of the stem-like cell marker CD133. These outcomes were boosted upon combination with metformin, an antihyperglycemic drug recently reported to possess different functions in cancer, while combination with collagenase, an extracellular matrix-depleting enzyme, produced detrimental effects.

CONCLUSION

HKTs represent a promising scalable formulation for treatment of the aggressive B16F10 melanoma, which is jam-packed with immunosuppressive and stem-like cell markers.

ALDH1A1-related stemness in high-grade serous ovarian cancer is a negative prognostic indicator but potentially targetable by EGFR/mTOR-PI3K/aurora kinase inhibitors

Poor chemotherapy response remains a major treatment challenge for high-grade serous ovarian cancer (HGSC). Cancer stem cells are the major contributors to relapse and treatment failure as they can survive conventional therapy. Our objectives were to characterise stemness features in primary patient-derived cell lines, correlate stemness markers with clinical outcome and test the response of our cells to both conventional and exploratory drugs. Tissue and ascites samples, treatment-naive and/or after neoadjuvant chemotherapy, were prospectively collected. Primary cancer cells, cultured under conditions favouring either adherent or spheroid growth, were tested for stemness markers; the same markers were analysed in tissue and correlated with chemotherapy response and survival. Drug sensitivity and resistance testing was performed with 306 oncology compounds. Spheroid growth condition HGSC cells showed increased stemness marker expression (including aldehyde dehydrogenase isoform I; ALDH1A1) as compared with adherent growth condition cells, and increased resistance to platinum and taxane. A set of eight stemness markers separated treatment-naive tumours into two clusters and identified a distinct subgroup of HGSC with enriched stemness features. Expression of ALDH1A1, but not most other stemness markers, was increased after neoadjuvant chemotherapy and its expression in treatment-naive tumours correlated with chemoresistance and reduced survival. In drug sensitivity and resistance testing, five compounds, including two PI3K-mTOR inhibitors, demonstrated significant activity in both cell culture conditions. Thirteen compounds, including EGFR, PI3K-mTOR and aurora kinase inhibitors, were more toxic to spheroid cells than adherent cells. Our results identify stemness markers in HGSC that are associated with a decreased response to conventional chemotherapy and reduced survival if expressed by treatment-naive tumours. EGFR, mTOR-PI3K and aurora kinase inhibitors are candidates for targeting this cell population. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Gliomasphere marker combinatorics: multidimensional flow cytometry detects CD44+/CD133+/ITGA6+/CD36+ signature

Glioblastoma is the most dangerous brain cancer. One reason for glioblastoma's aggressiveness are glioblastoma stem‐like cells. To target them, a number of markers have been proposed (CD133, CD44, CD15, A2B5, CD36, CXCR4, IL6R, L1CAM, and ITGA6). A comprehensive study of co‐expression patterns of them has, however, not been performed so far. Here, we mapped the multidimensional co‐expression profile of these stemness‐associated molecules. Gliomaspheres – an established model of glioblastoma stem‐like cells – were used. Seven different gliomasphere systems were subjected to multicolor flow cytometry measuring the nine markers CD133, CD44, CD15, A2B5, CD36, CXCR4, IL6R, L1CAM, and ITGA6 all simultaneously based on a novel 9‐marker multicolor panel developed for this study. The viSNE dimensionality reduction algorithm was applied for analysis. All gliomaspheres were found to express at least five different glioblastoma stem‐like cell markers. Multi‐dimensional analysis showed that all studied gliomaspheres consistently harbored a cell population positive for the molecular signature CD44+/CD133+/ITGA6+/CD36+. Glioblastoma patients with an enrichment of this combination had a significantly worse survival outcome when analyzing the two largest available The Cancer Genome Atlas datasets (MIT/Harvard Affymetrix: P = 0.0015, University of North Carolina Agilent: P = 0.0322). In sum, we detected a previously unknown marker combination – demonstrating feasibility, usefulness, and importance of high‐dimensional gliomasphere marker combinatorics.

Abnormal expression of the Notch and Wnt/β-catenin signaling pathways in stem-like ALDHhiCD44+ cells correlates highly with Ki-67 expression in breast cancer

Previous studies have reported that breast cancer stem cells may be closely associated with tumor metastasis, recurrence, and even the failure of chemotherapy and radiotherapy. The aim of the present study was to investigate whether important cell signaling pathways associated with drug resistance are activated in stem-like acetaldehyde dehydrogenase (ALDH)^hi cluster of differentiation (CD)44⁺ cells, and to analyze the association between ALDH^hiCD44⁺ cells and specific pathological features. ALDH^hiCD44⁺ cells and non-stem-like ALDH^lowCD44⁺ cells were separated from MDA-MB-231 cells by fluorescence-activated cell sorting, and the mRNA expression levels of Notch1 and β-catenin were estimated by performing quantitative polymerase chain reaction in the stem-like and non-stem-like cells. Line correlation analysis was used to evaluate the correlation between an immunohistochemical panel of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67, and ALDH^hiCD44⁺ cells from patients with invasive breast carcinoma. The mRNA levels of Notch1 and β-catenin were significantly higher in the ALDH^hiCD44⁺ cells compared with those in the ALDH^lowCD44⁺ cells (P<0.05); furthermore, the present study determined a high correlation (P<0.05) between the ALDH^hiCD44⁺ cells and Ki-67 expression (P=0.007), but no correlation (P≥0.05) with ER (P=0.065), PR (P=0.107) and HER2 (P=0.050). Overall, these data clearly indicate that ALDH^hiCD44⁺ cells may serve as novel diagnostic and prognostic factors in breast cancer.

Colonial growth and differentiation of epithelial cells derived from abattoir adult porcine livers

The parenchymal cell fraction was isolated from abattoir adult porcine livers and cultured in Dulbecco's Modified Eagles' medium/Ham's F12 medium (DMEM/F12; 1:1) medium supplemented with 5% foetal calf serum, 10 ng/mL glucagon, 10 µg/mL insulin, 60 ng/mL hydrocortisone and eight other factors (NAIR-1 medium). The fraction contained a number of epithelial cells other than hepatocytes, some of which attached to the culture plates as cell clusters and began to grow after 3 days in culture. These epithelial cells growing as colonies were found to express cytokeratin 18 by immunocytochemistry. After 7-8 days, duct-like structures emerged in the central parts of the colonies. The cells constituting the duct-like structures and some cells located outside the structures were positive for cytokeratin 19 and γ-glutamyltransferase (GGT). The albumin-positive cells were located in the outer parts of the colonies rather than their central parts. Albumin was also detectable in the cells surrounded by the duct-like structures. Moreover, cytochrome P450 IA1 was induced by 3-methylcholanthrene (3-MC) on day 16. These results suggest that porcine liver epithelial cell clusters may contain stem-like cells which can differentiate into mature hepatocytes or bile duct epithelial cells.