It has been popular and challenging to undertake researches on the delay of acquired resistance of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). As key cells for tumor initiation, cancer stem cells (CSC) play an important role in the process of resistance to EGFR-TKI. Although preliminary studies found that traditional Chinese medicine (TCM) could inhibit CSC properties and delay EGFR-TKI resistance, the specific molecular mechanism remains unclear. By summarizing the empirical syndrome treatment of EGFR-TKI resistance via TCM and combining recent researches on TCM intervention in CSC to delay EGFR-TKI resistance, this review discussed the potential molecular pathways and mechanisms of deceleration in resistance to EGFR-TKI by TCM via inhibiting CSC characteristics, in order to expand the research ideas of TCM in combination with targeted therapy.
Humans ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; ErbB Receptors/genetics* ; Protein Kinase Inhibitors/therapeutic use* ; Medicine, Chinese Traditional ; Neoplasms/drug therapy* ; Animals ; Drugs, Chinese Herbal/therapeutic use*

Objective The aim of this study was to investigate the effect of p38 on stem cell maintenance of pancreatic cancer. Methods Human pancreatic cancer cells PANC-1 were treated with different concentrations of 5-fluorouracil(5-FU)(0.5×IC₅₀, IC₅₀, and 2×IC₅₀) for 24 hours, and VX-702 (p38 phosphorylation inhibitor) was added, and the cells were inoculated in 6-well culture dishes with ultra-low adhesion to observe the changes of sphere tumors. The expression levels of cyclin-dependent kinase 2(CDK2), cyclin B1 and D1, Octamer-binding transcription factor 4(OCT4), SRY-box transcription factor 2(SOX2), Nanog and p38 were measured by Western blot. The mRNA expression levels of p38, OCT4, Nanog and SOX2 were tested by RT-PCR. Cell cycle, apoptosis, and the proportion of CD44⁺CD133⁺PANC-1 cells were evaluated by flow cytometry. Results The results showed that 5-FU inhibited the formation of tumor spheres in PANC-1 cells, increased CD44⁺CD133⁺cell fragments, down-regulated the expression of OCT4, Nanog and SOX2, and inhibited the stemness maintenance of PANC-1 tumor stem cells. Phosphorylation of PANC-1 cells was inhibited by a highly selective p38 MAPK inhibitor, VX-702(p38 mitogen-activated protein kinase inhibitor), which had the same effect as 5-FU treatment. When VX-702 combined with 5-FU was used to treat PANC-1 cells, the therapeutic effect was enhanced. Conclusion p38 inhibitors decreased PANC-1 cell activity and increased cell apoptosis. p38 inhibitors inhibit the stemness maintenance of pancreatic cancer stem cells.
Humans ; Phosphorylation/drug effects* ; Cell Line, Tumor ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors* ; Neoplastic Stem Cells/metabolism* ; Drug Resistance, Neoplasm/drug effects* ; Fluorouracil/pharmacology* ; Pancreatic Neoplasms/pathology* ; Apoptosis/drug effects* ; SOXB1 Transcription Factors/genetics* ; Octamer Transcription Factor-3/genetics*

Objective To investigate the regulatory effect of tumor necrosis factor-α-induced protein-8-like factor 2 (TIPE2) on the phenotype of lung cancer tumor-associated macrophages (TAM) and its influence on the stemness of lung cancer cells. Methods Mouse macrophage cell line RAW264.7 was cultured and infected with either LV-TIPE2 lentivirus or negative control LV-NC lentivirus. The TIPE2 expression in infected cells was assessed by real-time quantitative PCR (RT-qPCR) and Western blotting to verify transfection efficiency. The infected RAW264.7 cells were co-cultured with lung cancer cell line A549, and were divided into four groups: control group (RAW264.7 cells or A549 cells cultured alone), TAM group (RAW264.7 cells co-cultured with A549 cells), LV-NC group (RAW264.7 cells infected with LV-NC and co-cultured with A549 cells), LV-TIPE2 group (RAW264.7 cells infected with LV- TIPE2 and co-cultured with A549 cells). The RAW264.7 cells were collected after co-culture, and the expression of mannose receptor (CD206) protein of M2 macrophages was detected by cellular immunofluorescence staining. The proportions of M1 and M2 macrophages were detected by flow cytometry. After co-culture, A549 cells were collected, and their activity was assessed by CCK-8 assay. Self-renewal ability was evaluated using tumor cell pelleting experiment. The expression of stemness marker proteins-including cluster of differentiation 133 (CD133), transmembrane adhesion molecule (CD44), sex-determining region Y-box protein 2 (SOX2) and octamer-binding transcription factor 4 (OCT4)-was detected by Western blot. Results Compared with the control group or LV-NC group, the relative mRNA and protein expression levels of TIPE2 in RAW264.7 cells from the LV-TIPE2 group were significantly upregulated. Compared with the control group, the fluorescence intensity of M2-type macrophage marker CD206 protein in RAW264.7 cells from the TAM group was significantly increased, the proportion of M1-type macrophages was significantly decreased, and the proportion of M2-type macrophages was significantly increased. In contrast, compared with the TAM group, the fluorescence intensity of CD206 protein in RAW264.7 cells from the LV-TIPE2 group was significantly decreased, the proportion of M1-type macrophages was significantly increased, and the proportion of M2-type macrophages was significantly decreased. Compared with the control group, the proliferation activity of A549 cells in TAM group was significantly increased, the number of tumor pellet formation was significantly increased, and the relative expression levels of CD133, CD44, SOX2 and OCT4 were significantly up-regulated. However, compared with the TAM group, the proliferation activity of A549 cells from the LV-TIPE2 group was significantly decreased, the number of tumor pellet formation was significantly decreased, and the relative expression levels of CD133, CD44, SOX2 and OCT4 were significantly decreased. Conclusion TIPE2 can suppress the stemness of lung cancer cells by inhibiting the polarization of macrophages to M2-type, thereby exerting an anticancer effect.
Animals ; Mice ; Humans ; Tumor-Associated Macrophages/metabolism* ; Lung Neoplasms/genetics* ; Intracellular Signaling Peptides and Proteins/metabolism* ; RAW 264.7 Cells ; A549 Cells ; Phenotype ; Coculture Techniques ; Receptors, Cell Surface/metabolism* ; Neoplastic Stem Cells/metabolism* ; Mannose Receptor ; Mannose-Binding Lectins/metabolism* ; Lectins, C-Type/metabolism* ; Cell Polarity ; Macrophages/metabolism*

OBJECTIVE: To investigate the effect of miR-483-5p on hepatocellular carcinoma (HCC) cells proliferation and stemness, as well as the attenuating effect of Pien Tze Huang (PZH). METHODS: Differentially expressed miRNA between HepG2 cells and hepatic cancer stem-like cells (HCSCs) were identified by a miRNA microarray assay. miR-483-5p mimics were transfected into HepG2 cells to explore the effects of miR-483-5p on cell proliferation and stemness. HepG2 cells and HCSCs were treated with PZH (0, 0.25, 0.50 and 0.75 mg/mL) to explore the effects of PZH on the proliferation and stemness, both in non-induced state and the state induced by miR-483-5p mimics. RESULTS: miR-483-5p was significantly up-regulated in HCSCs and its overexpression increased cell proliferation and stemness in HepG2 cells (P<0.05). PZH not only significantly inhibited proliferation in HepG2 cells, but also significantly suppressed the cell proliferation and self-renewal of HCSCs (P<0.05). The effects of miR-483-5p mimics on proliferation and stemness of HepG2 cells were partially abolished by PZH. CONCLUSIONS miR-483-5p promotes proliferation and enhances stemness of HepG2 cells, which were attenuated by PZH, demonstrating that miR-483-5p is a potential molecular target for the treatment of HCC and provide experimental evidence to support clinical use of PZH for patients with HCC.
Humans ; MicroRNAs/metabolism* ; Cell Proliferation/drug effects* ; Liver Neoplasms/drug therapy* ; Carcinoma, Hepatocellular/drug therapy* ; Hep G2 Cells ; Neoplastic Stem Cells/metabolism* ; Drugs, Chinese Herbal/therapeutic use* ; Gene Expression Regulation, Neoplastic/drug effects*

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
Porphyromonas gingivalis/pathogenicity* ; Stearoyl-CoA Desaturase/metabolism* ; Humans ; Carcinoma, Squamous Cell/pathology* ; Mouth Neoplasms/metabolism* ; Animals ; Neoplastic Stem Cells/microbiology* ; Mice, Nude ; Mice ; Nod1 Signaling Adaptor Protein/metabolism* ; Kruppel-Like Transcription Factors/metabolism* ; Cell Line, Tumor

Cancer ranks as the second leading cause of death globally and has surpassed cardiovascular diseases to become the primary cause of mortality in developed countries. Cancer stem cells (CSCs), which play crucial roles in cancer recurrence, metastasis, and drug resistance, have attracted significant attention in targeted therapeutic strategies. Aptamers, with unique three-dimensional structures capable of specifically recognizing the surface markers of CSCs, show promising potential in targeted drug delivery systems. Compared with conventional antibodies, aptamers are praised for small molecular weights, low production costs, and easy chemical modification. This review systematically summarizes recent advances in aptamer research targeting the surface markers of CSCs, with particular emphasis on aptamer-drug conjugate systems targeting the markers including EpCAM, CD133, CD44, and ABCG2. Both in vitro cellular studies and in vivo animal models have demonstrated the definite anti-cancer efficacy of aptamer-based drug delivery systems, which are of great significance to develop novel therapeutic strategies and improving the therapeutic effects of CSC-targeted treatment. Thus, aptamer-based drug delivery system has broad application prospects in the field of precise cancer treatment.
Humans ; Neoplastic Stem Cells/metabolism* ; Aptamers, Nucleotide/therapeutic use* ; Drug Delivery Systems/methods* ; Neoplasms/drug therapy* ; Biomarkers, Tumor/metabolism* ; Animals ; Epithelial Cell Adhesion Molecule ; AC133 Antigen ; Hyaluronan Receptors

Recurrence and metastasis remain the leading cause of death in breast cancer patients due to the lack of effective treatment. A microenvironment suitable for cancer cell growth, referred to as pre-metastatic niche (PMN), is formed in distant organs before metastasis occurs. Myeloid-derived suppressor cells (MDSCs) are a heterogenous population of immature myeloid cells with immunosuppressive effects. They can expand in large numbers in breast cancer patients and participate in the formation of PMN. MDSCs can remodel the extracellular matrix of pulmonary vascular endothelial cells and recruit cancer stem cells to promote the lung metastasis of breast cancer. Furthermore, MDSCs facilitate immune evasion of breast cancer cells to impact the efficacy of immunotherapy. It is proposed that MDSCs represent a potential therapeutic target for the inhibition of recurrence and metastasis in breast cancer. Therapeutic strategies targeting MDSCs have shown promising efficacy in preclinical studies and clinical trials. This review presents a summary of the principal factors involved in the recruitment and activation of MDSCs during the formation of PMN, and outlines MDSCs functions such as immunosuppression and the current targeted therapies against MDSCs, aiming to provide new ideas for the treatment of distant metastases in breast cancer.
Humans ; Myeloid-Derived Suppressor Cells/immunology* ; Breast Neoplasms/immunology* ; Female ; Tumor Microenvironment ; Disease Progression ; Immunotherapy/methods* ; Neoplasm Metastasis ; Neoplastic Stem Cells

OBJECTIVE: To explore whether casticin (CAS) suppresses stemness in cancer stem-like cells (CSLCs) obtained from human cervical cancer (CCSLCs) and the underlying mechanism. METHODS: Spheres from HeLa and CaSki cells were used as CCSLCs. DNA methyltransferase 1 (DNMT1) activity and mRNA levels, self-renewal capability (Nanog and Sox2), and cancer stem cell markers (CD133 and CD44), were detected by a colorimetric DNMT activity/inhibition assay kit, quantitative real-time reverse transcription-polymerase chain reaction, sphere and colony formation assays, and immunoblot, respectively. Knockdown and overexpression of DNMT1 by transfection with shRNA and cDNA, respectively, were performed to explore the mechanism for action of CAS (0, 10, 30, and 100 nmol/L). RESULTS: DNMT1 activity was increased in CCSLCs compared with HeLa and CaSki cells (P<0.05). In addition, HeLa-derived CCSLCs transfected with DNMT1 shRNA showed reduced sphere and colony formation abilities, and lower CD133, CD44, Nanog and Sox2 protein expressions (P<0.05). Conversely, overexpression of DNMT1 in HeLa cells exhibited the oppositive effects. Furthermore, CAS significantly reduced DNMT1 activity and transcription levels as well as stemness in HeLa-derived CCSLCs (P<0.05). Interestingly, DNMT1 knockdown enhanced the inhibitory effect of CAS on stemness. As expected, DNMT1 overexpression reversed the inhibitory effect of CAS on stemness in HeLa cells. CONCLUSION CAS effectively inhibits stemness in CCSLCs through suppression of DNMT1 activation, suggesting that CAS acts as a promising preventive and therapeutic candidate in cervical cancer.
Female ; Humans ; Cell Line, Tumor ; HeLa Cells ; Neoplastic Stem Cells/metabolism* ; RNA, Small Interfering/metabolism* ; Uterine Cervical Neoplasms/metabolism*

Objective: To explore the key deubiquitinating enzymes that maintain the stemness of liver cancer stem cells and provide new ideas for targeted liver cancer therapy. Methods: The high-throughput CRISPR screening technology was used to screen the deubiquitinating enzymes that maintain the stemness of liver cancer stem cells. RT-qPCR and Western blot were used to analyze gene expression levels. Stemness of liver cancer cells was detected by spheroid-formation and soft agar colony formation assays. Tumor growth in nude mice was detected by subcutaneous tumor-bearing experiments. Bioinformatics and clinical samples were examined for the clinical significance of target genes. Results: MINDY1 was highly expressed in liver cancer stem cells. The expression of stem markers, the self-renewal ability of cells, and the growth of transplanted tumors were significantly reduced and inhibited after knocking out MINDY1, and its mechanism of action may be related to the regulation of the Wnt signaling pathway. The expression level of MINDY1 was higher in liver cancer tissues than that in adjacent tumors, which was closely related to tumor progression, and its high expression was an independent risk factor for a poor prognosis of liver cancer. Conclusion: The deubiquitinating enzyme MINDY1 promotes stemness in liver cancer cells and is one of the independent predictors of poor prognosis in liver cancer.
Animals ; Mice ; Cell Line, Tumor ; Mice, Nude ; Liver Neoplasms/pathology* ; Prognosis ; Deubiquitinating Enzymes/metabolism* ; Neoplastic Stem Cells/pathology* ; Gene Expression Regulation, Neoplastic

Objective: To investigate the expression of programmed death protein-ligand 1 (PD-L1) in liver cancer stem-like cells (LCSLC) and its effect on the characteristics of tumor stem cells and tumor biological function, to explore the upstream signaling pathway regulating PD-L1 expression in LCSLC and the downstream molecular mechanism of PD-L1 regulating stem cell characteristics, also tumor biological functions. Methods: HepG2 was cultured by sphere-formating method to obtain LCSLC. The expressions of CD133 and other stemness markers were detected by flow cytometry, western blot and real-time quantitative polymerase chain reaction (RT-qPCR) were used to detect the expressions of stemness markers and PD-L1. The biological functions of the LCSLC were tested by cell function assays, to confirm that the LCSLC has the characteristics of tumor stem cells. LCSLC was treated with cell signaling pathway inhibitors to identify relevant upstream signaling pathways mediating PD-L1 expression changes. The expression of PD-L1 in LCSLC was down regulated by small interfering RNA (siRNA), the expression of stem cell markers, tumor biological functions of LCSLC, and the changes of cell signaling pathways were detected. Results: Compared with HepG2 cells, the expression rate of CD133 in LCSLC was upregulated [(92.78±6.91)% and (1.40±1.77)%, P<0.001], the expressions of CD133, Nanog, Oct4A and Snail in LCSLC were also higher than those in HepG2 cells (P<0.05), the number of sphere-formating cells increased on day 7 [(395.30±54.05) and (124.70±19.30), P=0.001], cell migration rate increased [(35.41±6.78)% and (10.89±4.34)%, P=0.006], the number of transmembrane cells increased [(75.77±10.85) and (20.00±7.94), P=0.002], the number of cloned cells increased [(120.00±29.51) and (62.67±16.77), P=0.043]. Cell cycle experiments showed that LCSLC had significantly more cells in the G(0)/G(1) phase than those in HepG2 [(54.89±3.27) and (32.36±1.50), P<0.001]. The tumor formation experiment of mice showed that the weight of transplanted tumor in LCSLC group was (1.32±0.17)g, the volume is (1 779.0±200.2) mm(3), were higher than those of HepG2 cell [(0.31±0.06)g and (645.6±154.9)mm(3), P<0.001]. The expression level of PD-L1 protein in LCSLC was 1.88±0.52 and mRNA expression level was 2.53±0.62, both of which were higher than those of HepG2 cells (P<0.05). The expression levels of phosphorylation signal transduction and transcription activation factor 3 (p-STAT3) and p-Akt in LCSLC were higher than those in HepG2 cells (P<0.05). After the expression of p-STAT3 and p-Akt was down-regulated by inhibitor treatment, the expression of PD-L1 was also down-regulated (P<0.05). In contrast, the expression level of phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2) in LCSLC was lower than that in HepG2 cells (P<0.01), there was no significant change in PD-L1 expression after down-regulated by inhibitor treatment (P>0.05). After the expression of PD-L1 was knockdown by siRNA, the expressions of CD133, Nanog, Oct4A and Snail in LCSLC were decreased compared with those of siRNA-negative control (NC) group (P<0.05). The number of sphere-formating cells decreased [(45.33±12.01) and (282.00±29.21), P<0.001], the cell migration rate was lower than that in siRNA-NC group [(20.86±2.74)% and (46.73±15.43)%, P=0.046], the number of transmembrane cells decreased [(39.67±1.53) and (102.70±11.59), P=0.001], the number of cloned cells decreased [(57.67±14.57) and (120.70±15.04), P=0.007], the number of cells in G(0)/G(1) phase decreased [(37.68±2.51) and (57.27±0.92), P<0.001], the number of cells in S phase was more than that in siRNA-NC group [(30.78±0.52) and (15.52±0.83), P<0.001]. Tumor formation in mice showed that the tumor weight of shRNA-PD-L1 group was (0.47±0.12)g, the volume is (761.3±221.4)mm(3), were lower than those of shRNA-NC group [(1.57±0.45)g and (1 829.0±218.3)mm(3), P<0.001]. Meanwhile, the expression levels of p-STAT3 and p-Akt in siRNA-PD-L1 group were decreased (P<0.05), while the expression levels of p-ERK1/2 and β-catenin did not change significantly (P>0.05). Conclusion: Elevated PD-L1 expression in CD133(+) LCSLC is crucial to maintain stemness and promotes the tumor biological function of LCSLC.
Humans ; Animals ; Mice ; Proto-Oncogene Proteins c-akt/metabolism* ; B7-H1 Antigen/metabolism* ; Ligands ; Liver Neoplasms/pathology* ; RNA, Small Interfering/metabolism* ; Neoplastic Stem Cells/physiology* ; Cell Line, Tumor ; Cell Proliferation