Attenuation of PI3K-Akt-mTOR Pathway to Reduce Cancer Stemness on Chemoresistant Lung Cancer Cells by Shikonin and Synergy with BEZ235 Inhibitor

Role of noncoding RNA as a pacemaker in cancer stem cell regulation: a review article

Accumulated evidence supported the crucial role of a tiny population of cells within the tumor called cancer stem cells (CSCs) in cancer origination, and proliferation. Additionally, these cells are distinguished by their self-renewal, differentiation, and therapeutic resistance capabilities. Interestingly, many studies recorded dysregulation of different types of noncoding RNAs, such as microRNA (miRNA) and long non-coding RNA (LncRNA), in cancer cells as well as CSCs. Moreover, several studies also supported the regulation of the transcription factors and signaling pathways required for CSC progression by these noncoding RNAs. However, the exact biological functions of all these noncoding RNAs are not well understood yet. These findings are of great interest, implying usage of noncoding RNA as therapeutic tool to target these cells. In this review, we provide an insight into how noncoding RNAs regulate CSCs and how this correlation is manipulated to develop new therapies to eradicate cancer cells successfully.

Tanshinone IIA affects the proliferation of A549/Tax by affecting the expression of MMP7 through the PI3K-AKT-mTOR signaling pathway

OBJECTIVE

This study aims to explore whether tanshinone IIA can act on paclitaxel-resistant non-small cell lung cancer A549/Tax and analyze the possible mechanisms involved.

METHODS

Using the Cell Counting Kit-8 (CCK-8), we preliminarily analyzed whether tanshinone IIA has an inhibitory effect on A549/Tax cells. We utilized public datasets, self-collected transcriptome datasets, and drug target analysis to identify potential targets. We employed real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) to detect the expression of core genes before and after drug treatment to analyze potential target genes and validated them using data from The Cancer Genome Atlas (TCGA). We conducted enrichment analysis on co-expressed genes of the target genes to explore potential mechanisms. Furthermore, we employed molecular docking and western blot to verify the possible mechanisms involved.

RESULTS

The CCK8 results indicated that tanshinone IIA has a significant inhibitory effect on A549/Tax cells. The qPCR results and the analysis of TCGA data indicated that MMP7 is the target gene. Enrichment results of MMP7 co-expressed genes suggested that the PI3K-AKT signaling pathway might play a key role. Molecular docking results indicated that tanshinone IIA has strong binding activity with PI3K, AKT, mTOR, and MMP7. Western blotting results showed that tanshinone IIA might inhibit MMP7 through the PI3K-AKT-mTOR signaling pathway.

CONCLUSIONS

Tanshinone IIA may affect the proliferation of A549/Tax by influencing the expression of MMP7 through the PI3K-AKT-mTOR signaling pathway.

Epigenetic modifications in early stage lung cancer: pathogenesis, biomarkers, and early diagnosis

The integration of liquid biopsy with epigenetic markers offers significant potential for early lung cancer detection and personalized treatment. Epigenetic alterations, including DNA methylation, histone modifications, and noncoding RNA changes, often precede genetic mutations and are critical in cancer progression. In this study, we explore how liquid biopsy, combined with epigenetic markers, can provide early detection of lung cancer, potentially predicting onset up to 4 years before clinical diagnosis. We discuss the challenges of targeting epigenetic regulators, which could disrupt cellular balance if overexploited, and the need for maintaining key gene expressions in therapeutic applications. This review highlights the promise and challenges of using liquid biopsy and epigenetic markers for early-stage lung cancer diagnosis, with a focus on optimizing treatment strategies for personalized and precision medicine.

Application of an Integrated Single-Cell and Three-Dimensional Spheroid Culture Platform for Investigating Drug Resistance Heterogeneity and Epithelial-Mesenchymal Transition (EMT) in Lung Cancer Subclones

Lung cancer is a leading cause of cancer-related mortality worldwide, largely due to its heterogeneity and intrinsic drug resistance. Malignant pleural effusions (MPEs) provide diverse tumor cell populations ideal for studying these complexities. Although chemotherapy and targeted therapies can be initially effective, subpopulations of cancer cells with phenotypic plasticity often survive treatment, eventually developing resistance. Here, we integrated single-cell isolation and three-dimensional (3D) spheroid culture to dissect subclonal heterogeneity and drug responses, aiming to inform precision medicine approaches. Using A549 lung cancer cells, we established a cisplatin-resistant line and isolated three resistant subclones (Holoclone, Meroclone, Paraclone) via single-cell sorting. In 3D spheroids, Docetaxel and Alimta displayed higher IC50 values than in 2D cultures, suggesting that 3D models better reflect clinical dosing. Additionally, MPE-derived Holoclone and Paraclone subclones exhibited distinct sensitivities to Giotrif and Capmatinib, revealing their heterogeneous drug responses. Molecular analyses confirmed elevated ABCB1, ABCG2, cancer stem cell (CSC) markers (OCT4, SOX2, CD44, CD133), and epithelial-mesenchymal transition (EMT) markers (E-cadherin downregulation, increased Vimentin, N-cadherin, Twist) in resistant subclones, correlating with enhanced migration and invasion. This integrated approach clarifies the interplay between heterogeneity, CSC/EMT phenotypes, and drug resistance, providing a valuable tool for predicting therapeutic responses and guiding personalized, combination-based lung cancer treatments.

The complex interplay between redox dysregulation and mTOR signaling pathway in cancer: A rationale for cancer treatment

The mechanistic target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that plays a critical role in regulating cellular processes such as growth, proliferation, and metabolism in healthy cells. Dysregulation of mTOR signaling and oxidative stress have been implicated in various diseases including cancer. This review aims to provide an overview of the current understanding of mTOR and its involvement in cell survival and the regulation of cancer cell metabolism as well as its complex interplay with reactive oxygen species (ROS). On the one hand, ROS can inhibit or activate mTOR pathway in cancer cells through various mechanisms. Conversely, mTOR signaling can induce oxidative stress in tumor cells notably due to the inhibition in the expression of antioxidant enzyme genes. Since mTOR is often activated and plays crucial role in cancer cell survival, the use of mTOR inhibitors, which often induce ROS accumulation, could be an interesting approach for cancer treatment. This review will address the advantages, disadvantages, combination strategies, and limitations associated with therapeutic modulation of mTOR signaling pathway in cancer treatment.

KNTC1 functions as a potential biomarker and oncogene regulating proliferation, migration and apoptosis in gastric cancer

BACKGROUND

As one of the most prevalent cancers, gastric cancer (GC) exhibits a remarkably high morbidity and mortality rate. To date, effective diagnostic and prognostic markers and therapeutic targets for GC are still lacking. Kinetochore associated 1 (KNTC1) is one of the proteins involved in chromosome segregation. However, the diagnostic and prognostic value of KNTC1 and its biological function in GC remain unknown.

METHODS

In this study, Gene Expression Omnibus (GEO) datasets were utilized to identify differentially expressed genes (DEGs). Prognostic and diagnostic value were assessed by Kaplan-Meier plotter and receiver operating characteristic (ROC) curve. The expression of KNTC1 was verified by q-PCR, immunohistochemistry (IHC) and Western blotting. Subsequently, KNTC1 knockdown was employed to investigate its effect on GC cells. Gene set enrichment analysis (GSEA) revealed a pathway regulated by KNTC1, which was further verified by Western blotting.

RESULTS

Four highly expressed genes (ESPL1, RAD54L, KNTC1, TACC3) were identified as biomarkers for GC diagnosis and prognosis. Notably, the value of KNTC1 as a biomarker for GC was newly revealed. Single-cell and immune analyses revealed that KNTC1 contributed to the suppression of the GC immune microenvironment. In clinical samples, we demonstrated high expression of KNTC1 in GC tissues. KNTC1 knockdown suppressed proliferation and migration while promoting apoptosis of GC cells. Additionally, KNTC1 may affect GC cells by regulating the PI3K/Akt/mTOR pathway.

CONCLUSIONS

KNTC1 acts as a potential diagnostic and prognostic marker for GC. It may promote proliferation and migration while inhibiting apoptosis of GC cells via the PI3K/Akt/mTOR pathway.

FDFT1 maintains glioblastoma stem cells through activation of the Akt pathway

BACKGROUND

Cancer stem cells (CSCs) have unique metabolic characteristics and are hypothesized to contribute significantly to the recurrence and drug resistance of glioblastoma multiforme (GBM). However, the reliance on mitochondrial metabolism and the underlying mechanism of glioblastoma stem cells (GSCs) remains to be elucidated.

METHODS

To quantify differential mitochondrial protein expression between GSCs and differentiated cells, a mass spectrum screen was applied by the Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) technique. Functional experiments including CCK8, neurosphere formation, flow cytometry, transwell, and wound healing assays were conducted to evaluate GBM cell malignant phenotype. The potential molecular mechanism of FDFT1 was screened by RNA-seq analyses. The candidate target genes were validated through RT-qPCR and western blot analyses.

RESULTS

As a top candidate, FDFT1 protein expression in GSCs was elevated relative to their differentiated counterparts. Functionally, the knockdown of FDFT1 suppressed the GBM cell proliferation and migration, while simultaneously enhancing sensitivity to temozolomide. Treatment with both the FDFT1 inhibitor (YM-53601) and simvastatin (an HMG-CoA reductase inhibitor) induced apoptosis in GSCs. Mechanistically, FDFT1 was transcriptionally regulated by SREBP2 but not SREBP1. Furthermore, FDFT1 activates the AKT pathway to regulate tumor metabolism and maintain the stemness of tumor cells.

CONCLUSIONS

GSCs exhibit a dependency on FDFT1-mediated mevalonate metabolism. Inhibition of FDFT1 could represent a potent strategy to eliminate GSCs.

Association of Wild-Type TP53 with Downregulation of Lovastatin Sensitivity in Human Non-Small Cell Lung Cancer Cells

Statins inhibit 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme of the mevalonate pathway, and reduce cholesterol synthesis. They also have been demonstrated to improve prognosis in patients with various cancers, suggesting a potential anti-cancer effect of statins. However, there is no consensus on the molecular targets of statins for their anti-cancer effects. Docetaxel (DOC) is a microtubule-stabilizing agent currently used as a chemotherapeutic drug in several cancers, including lung cancer. Interestingly, the anti-cancer effects of either drug that are related to abnormal or wild-type TP53 gene have been implied. Therefore, the drug sensitivity of DOC and lovastatin in human lung cancer cells was evaluated. We found that H1355 (mutant TP53-E285K), CL1 (mutant TP53-R248W), and H1299 (TP53-null) human non-small cell lung cancer cells were more sensitive to lovastatin than A549 and H460 cells expressing wild-type TP53. Conversely, A549 and H460 cells showed higher sensitivity to DOC than H1299 and CL1 cells, as demonstrated by the MTT assay. When endogenous TP53 activity was inhibited by pifithrin-α in A549 and H460 cells, lovastatin sensitivities significantly increased, and cancer cell viabilities markedly reduced. These results indicate that TP53 status is associated with the anti-cancer effect of statins in human lung cancer cells. Mutated or null TP53 status is correlated with higher statin sensitivity. Furthermore, DOC-resistant H1299 (H1299/D8) cells showed significant sensitivity to lovastatin treatment compared to DOC-resistant A549 (A549/D16) cells, indicating a potential application of statins/chemotherapy combination therapy to control wild-type and abnormal TP53-containing human lung tumors.

Cancer Stem Cells from Definition to Detection and Targeted Drugs

Cancers remain the second leading cause of mortality in the world. Preclinical and clinical studies point an important role of cancer/leukaemia stem cells (CSCs/LSCs) in the colonisation at secondary organ sites upon metastatic spreading, although the precise mechanisms for specific actions are still not fully understood. Reviewing the present knowledge on the crucial role of CSCs/LSCs, their plasticity, and population heterogeneity in treatment failures in cancer patients is timely. Standard chemotherapy, which acts mainly on rapidly dividing cells, is unable to adequately affect CSCs with a low proliferation rate. One of the proposed mechanisms of CSC resistance to anticancer agents is the fact that these cells can easily shift between different phases of the cell cycle in response to typical cell stimuli induced by anticancer drugs. In this work, we reviewed the recent studies on CSC/LSC alterations associated with disease recurrence, and we systematised the functional assays, markers, and novel methods for CSCs screening. This review emphasises CSCs' involvement in cancer progression and metastasis, as well as CSC/LSC targeting by synthetic and natural compounds aiming at their elimination or modulation of stemness properties.