1.Impact of Folic Acid on the Resistance of Non-small Cell Lung Cancer Cells to Osimertinib by Regulating Methylation of DUSP1.
Chinese Journal of Lung Cancer 2024;26(12):881-888
BACKGROUND:
Drug resistance is the main cause of high mortality of lung cancer. This study was conducted to investigate the effect of folic acid (FA) on the resistance of non-small cell lung cancer (NSCLC) cells to Osimertinib (OSM) by regulating the methylation of dual specificity phosphatase 1 (DUSP1).
METHODS:
The OSM resistant NSCLC cell line PC9R was establishd by gradually escalation of OSM concentration in PC9 cells. PC9R cells were randomly grouped into Control group, OSM group (5 μmol/L OSM), FA group (600 nmol/L FA), methylation inhibitor decitabine (DAC) group (10 μmol/L DAC), FA+OSM group (600 nmol/L FA+5 μmol/L OSM), and FA+OSM+DAC group (600 nmol/L FA+5 μmol/L OSM+10 μmol/L DAC). CCK-8 method was applied to detect cell proliferation ability. Scratch test was applied to test the ability of cell migration. Transwell assay was applied to detect cell invasion ability. Flow cytometry was applied to measure and analyze the apoptosis rate of cells in each group. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) method was applied to detect the expression level of DUSP1 mRNA in cells. Methylation specific PCR (MSP) was applied to detect the methylation status of the DUSP1 promoter region in each group. Western blot was applied to analyze the expression levels of DUSP1 protein and key proteins in the DUSP1 downstream mitogen-activated protein kinase (MAPK) signaling pathway in each group.
RESULTS:
Compared with the Control group, the cell OD450 values (48 h, 72 h), scratch healing rate, number of cell invasions, and expression of DUSP1 in the OSM group were obviously decreased (P<0.05); the apoptosis rate, the methylation level of DUSP1, the expression of p38 MAPK protein, and the phosphorylation level of extracellular regulated protein kinases (ERK) were obviously increased (P<0.05); the cell OD450 values (48, 72 h), scratch healing rate, number of cell invasions, and expression of DUSP1 in the DAC group were obviously increased (P<0.05); the apoptosis rate, the expression of p38 MAPK protein, the phosphorylation level of ERK, and the methylation level of DUSP1 were obviously reduced (P<0.05). Compared with the OSM group, the cell OD450 values (48, 72 h), scratch healing rate, number of cell invasions, and expression of DUSP1 in the FA+OSM group were obviously decreased (P<0.05); the apoptosis rate, the methylation level of DUSP1, the expression of p38 MAPK protein, and the phosphorylation level of ERK were obviously increased (P<0.05). Compared with the FA+OSM group, the cell OD450 values (48, 72 h), scratch healing rate, number of cell invasions, and expression of DUSP1 in the FA+OSM+DAC group were obviously increased; the apoptosis rate, the methylation level of DUSP1, the expression of p38 MAPK protein, and the phosphorylation level of ERK were obviously reduced (P<0.05).
CONCLUSIONS
FA may inhibit DUSP1 expression by enhancing DUSP1 methylation, regulate downstream MAPK signal pathway, then promote apoptosis, inhibit cell invasion and metastasis, and ultimately reduce OSM resistance in NSCLC cells.
Humans
;
Carcinoma, Non-Small-Cell Lung/genetics*
;
Lung Neoplasms/genetics*
;
Dual Specificity Phosphatase 1/pharmacology*
;
Cell Proliferation
;
p38 Mitogen-Activated Protein Kinases/pharmacology*
;
Methylation
;
Apoptosis
;
Cell Line, Tumor
2.Study on the Role and Mechanism of METTL3 Mediating the Up-regulation of m6A Modified Long Non-coding RNA THAP7-AS1 in Promoting the Occurrence of Lung Cancer.
Yu ZHANG ; Yanhong WANG ; Mei LIU
Chinese Journal of Lung Cancer 2024;26(12):919-933
BACKGROUND:
Lung cancer is a major threat to human health. The molecular mechanisms related to the occurrence and development of lung cancer are complex and poorly known. Exploring molecular markers related to the development of lung cancer is helpful to improve the effect of early diagnosis and treatment. Long non-coding RNA (lncRNA) THAP7-AS1 is known to be highly expressed in gastric cancer, but has been less studied in other cancers. The aim of the study is to explore the role and mechanism of methyltransferase-like 3 (METTL3) mediated up-regulation of N6-methyladenosine (m6A) modified lncRNA THAP7-AS1 expression in promoting the development of lung cancer.
METHODS:
Samples of 120 lung cancer and corresponding paracancerous tissues were collected. LncRNA microarrays were used to analyze differentially expressed lncRNAs. THAP7-AS1 levels were detected in lung cancer, adjacent normal tissues and lung cancer cell lines by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The diagnostic value of THAP7-AS1 in lung cancer and the relationship between THAP7-AS1 expression and survival rate and clinicopathological parameters were analyzed. Bioinformatics analysis, methylated RNA immunoprecipitation (meRIP), RNA pull-down and RNA-immunoprecipitation (RIP) assay were used to investigate the molecular regulation mechanism of THAP7-AS1. Cell proliferation, migration, invasion and tumorigenesis of SPC-A-1 and NCI-H1299 cells were determined by MTS, colony-formation, scratch, Transwell and xenotransplantation in vivo, respectively. Expression levels of phosphoinositide 3-kinase/protein kenase B (PI3K/AKT) signal pathway related protein were detected by Western blot.
RESULTS:
Expression levels of THAP7-AS1 were higher in lung cancer tissues and cell lines (P<0.05). THAP7-AS1 has certain diagnostic value in lung cancer [area under the curve (AUC)=0.737], and its expression associated with overall survival rate, tumor size, tumor-node-metastasis (TNM) stage and lymph node metastasis (P<0.05). METTL3-mediated m6A modification enhanced THAP7-AS1 expression. The cell proliferation, migration, invasion and the volume and mass of transplanted tumor were all higher in the THAP7-AS1 group compared with the NC group and sh-NC group of SPC-A-1 and NCI-H1299 cells, while the cell proliferation, migration and invasion were lower in the sh-THAP7-AS1 group (P<0.05). THAP7-AS1 binds specifically to Cullin 4B (CUL4B). The cell proliferation, migration, invasion, and expression levels of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), phosphoinositide-3 kinase, catalytic subunit delta (PIK3CD), phospho-phosphatidylinositol 3-kinase (p-PI3K), phospho-protein kinase B (p-AKT) and phospho-mammalian target of rapamycin (p-mTOR) were higher in the THAP7-AS1 group compared with the Vector group of SPC-A-1 and NCI-H1299 cells (P<0.05).
CONCLUSIONS
LncRNA THAP7-AS1 is stably expressed through m6A modification mediated by METTL3, and combines with CUL4B to activate PI3K/AKT signal pathway, which promotes the occurrence and development of lung cancer.
Humans
;
Lung Neoplasms/pathology*
;
RNA, Long Noncoding/metabolism*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Up-Regulation
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Cell Line, Tumor
;
Cell Proliferation/genetics*
;
Gene Expression Regulation, Neoplastic
;
Methyltransferases/metabolism*
;
Cullin Proteins/genetics*
3.Asperuloside Promotes Apoptosis of Cervical Cancer Cells through Endoplasmic Reticulum Stress-Mitochondrial Pathway.
Zhi-Min QI ; Xia WANG ; Xia LIU ; Juan ZHAO
Chinese journal of integrative medicine 2024;30(1):34-41
OBJECTIVE:
To investigate the effects of asperuloside on cervical cancer based on endoplasmic reticulum (ER) stress and mitochondrial pathway.
METHODS:
Different doses (12.5-800 µg/mL) of asperuloside were used to treat cervical cancer cell lines Hela and CaSki to calculate the half maximal inhibitory concentration (IC50) of asperuloside. The cell proliferation was analyzed by clone formation assay. Cell apoptosis, intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were determined by flow cytometry. The protein expressions of cleaved-caspase-3, Bcl-2, Bax, Cyt-c, cleaved-caspase-4 and glucose-regulated protein 78 (GRP78) were analyzed by Western blot. And the inhibitor of ER stress, 4-phenyl butyric acid (4-PBA) was used to treat cervical cancer cells to further verify the role of ER stress in the apoptosis of cervical cancer cells induced by asperuloside.
RESULTS:
Asperuloside of 325, 650, and 1300 µg/mL significantly inhibited the proliferation and promoted apoptosis of Hela and CaSki cells (P<0.01). All doses of asperuloside significantly increased intracellular ROS levels, reduced mitochondrial membrane potential, significantly reduced Bcl-2 protein expression level, and increased Bax, Cyt-c, GRP78 and cleaved-caspase-4 expressions (P<0.01). In addition, 10 mmol/L 4-PBA treatment significantly promoted cell proliferation and reduced apoptosis (P<0.05), and 650 µg/mL asperuloside could reverse 4-PBA-induced increased cell proliferation, decreased apoptosis and cleaved-caspase-3, -4 and GRP78 protein expressions (P<0.05).
CONCLUSION
Our study revealed the role of asperuloside in cervical cancer, suggesting that asperuloside promotes apoptosis of cervical cancer cells through ER stress-mitochondrial pathway.
Female
;
Humans
;
Uterine Cervical Neoplasms/metabolism*
;
Caspase 3/metabolism*
;
bcl-2-Associated X Protein/metabolism*
;
Reactive Oxygen Species/metabolism*
;
Endoplasmic Reticulum Chaperone BiP
;
HeLa Cells
;
Proto-Oncogene Proteins c-bcl-2/metabolism*
;
Apoptosis
;
Endoplasmic Reticulum Stress
;
Cell Line, Tumor
4.Hydroxysafflor Yellow A Promotes HaCaT Cell Proliferation and Migration by Regulating HBEGF/EGFR and PI3K/AKT Pathways and Circ_0084443.
Yue ZHANG ; Yan-Wei XIAO ; Jing-Xin MA ; Ao-Xue WANG
Chinese journal of integrative medicine 2024;30(3):213-221
OBJECTIVE:
To investigate the effect and possible mechanism of hydroxysafflor yellow A (HSYA) on human immortalized keratinocyte cell proliferation and migration.
METHODS:
HaCaT cells were treated with HSYA. Cell proliferation was detected by the cell counting kit-8 assay, and cell migration was measured using wound healing assay and Transwell migration assay. The mRNA and protein expression levels of heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF), EGF receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), mammalian target of rapamycin (mTOR), and hypoxia-inducible factor-1α (HIF-1α) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. Circ_0084443-overexpressing HaCaT cells and empty plasmid HaCaT cells were constructed using the lentiviral stable transfection and treated with HSYA. The expression of circ_0084443 was detected by qRT-PCR.
RESULTS:
HSYA (800 µmol/L) significantly promoted HaCaT cell proliferation and migration (P<0.05 or P<0.01). It also increased the mRNA and protein expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and increased the phosphorylation levels of PI3K and AKT (P<0.05 or P<0.01). Furthermore, HSYA promoted HaCaT cell proliferation and migration via the HBEGF/EGFR and PI3K/AKT/mTOR signaling pathways (P<0.01). Circ_0084443 attenuated the mRNA expression levels of HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α (P<0.05). HSYA inhibited the circ_0084443 expression, further antagonized the inhibition of circ_0084443 on HBEGF, EGFR, PI3K, AKT, mTOR and HIF-1α, and promoted the proliferation of circ_0084443-overexpressing HaCaT cells (P<0.05 or P<0.01). However, HSYA could not influence the inhibitory effect of circ_0084443 on HaCaT cell migration (P>0.05).
CONCLUSION
HSYA played an accelerative role in HaCaT cell proliferation and migration, which may be attributable to activating HBEGF/EGFR and PI3K/AKT signaling pathways, and had a particular inhibitory effect on the keratinocyte negative regulator circ_0084443.
Humans
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Phosphatidylinositol 3-Kinase
;
Phosphatidylinositol 3-Kinases/metabolism*
;
ErbB Receptors/genetics*
;
TOR Serine-Threonine Kinases/metabolism*
;
Cell Proliferation
;
RNA, Messenger/genetics*
;
Cell Movement
;
Cell Line, Tumor
;
Chalcone/analogs & derivatives*
;
Quinones
5.Monotropein Induced Apoptosis and Suppressed Cell Cycle Progression in Colorectal Cancer Cells.
Quan GAO ; Lin LI ; Qi-Man ZHANG ; Qin-Song SHENG ; Ji-Liang ZHANG ; Li-Jun JIN ; Rui-Yan SHANG
Chinese journal of integrative medicine 2024;30(1):25-33
OBJECTIVE:
To determine whether monotropein has an anticancer effect and explore its potential mechanisms against colorectal cancer (CRC) through network pharmacology and molecular docking combined with experimental verification.
METHODS:
Network pharmacology and molecular docking were used to predict potential targets of monotropein against CRC. Cell counting kit assay, plate monoclonal assay and microscopic observation were used to investigate the antiproliferative effects of monotropein on CRC cells HCT116, HT29 and LoVo. Flow cytometry and scratch assay were used to analyze apoptosis and cell cycle, as well as cell migration, respectively in HCT116, HT29, and LoVo cells. Western blotting was used to detect the expression of proteins related to apoptosis, cell cycle, and cell migration, and the expression of proteins key to the Akt pathway.
RESULTS:
The Gene Ontology and Reactome enrichment analyses indicated that the anticancer potential of monotropein against CRC might be involved in multiple cancer-related signaling pathways. Among these pathways, RAC-beta serine/threonine-protein kinase (Akt1, Akt2), cyclin-dependent kinase 6 (CDK6), matrix metalloproteinase-9 (MMP9), epidermal growth factor receptor (EGFR), cell division control protein 42 homolog (CDC42) were shown as the potential anticancer targets of monotropein against CRC. Molecular docking suggested that monotropein may interact with the 6 targets (Akt1, Akt2, CDK6, MMP9, EGFR, CDC42). Subsequently, cell activity of HCT116, HT29 and LoVo cell lines were significantly suppressed by monotropein (P<0.05). Furthermore, our research revealed that monotropein induced cell apoptosis by inhibiting Bcl-2 and increasing Bax, induced G1-S cycle arrest in colorectal cancer by decreasing the expressions of CyclinD1, CDK4 and CDK6, inhibited cell migration by suppressing the expressions of CDC42 and MMP9 (P<0.05), and might play an anticancer role through Akt signaling pathway.
CONCLUSION
Monotropein exerts its antitumor effects primarily by arresting the cell cycle, causing cell apoptosis, and inhibiting cell migration. This indicates a high potential for developing novel medication for treating CRC.
Humans
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Cell Proliferation
;
Matrix Metalloproteinase 9
;
Molecular Docking Simulation
;
Cell Cycle
;
ErbB Receptors
;
Apoptosis
;
Colorectal Neoplasms/pathology*
;
Cell Line, Tumor
6.Electroacupuncture Promotes Functional Recovery after Facial Nerve Injury in Rats by Regulating Autophagy via GDNF and PI3K/mTOR Signaling Pathway.
Jun-Peng YAO ; Xiu-Mei FENG ; Lu WANG ; Yan-Qiu LI ; Zi-Yue ZHU ; Xiang-Yun YAN ; Yu-Qing YANG ; Ying LI ; Wei ZHANG
Chinese journal of integrative medicine 2024;30(3):251-259
OBJECTIVE:
To explore the mechanism of electroacupuncture (EA) in promoting recovery of the facial function with the involvement of autophagy, glial cell line-derived neurotrophic factor (GDNF), and phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway.
METHODS:
Seventy-two male Sprague-Dawley rats were randomly allocated into the control, sham-operated, facial nerve injury (FNI), EA, EA+3-methyladenine (3-MA), and EA+GDNF antagonist groups using a random number table, with 12 rats in each group. An FNI rat model was established with facial nerve crushing method. EA intervention was conducted at Dicang (ST 4), Jiache (ST 6), Yifeng (SJ 17), and Hegu (LI 4) acupoints for 2 weeks. The Simone's 10-Point Scale was utilized to monitor the recovery of facial function. The histopathological evaluation of facial nerves was performed using hematoxylin-eosin (HE) staining. The levels of Beclin-1, light chain 3 (LC3), and P62 were detected by immunohistochemistry (IHC), immunofluorescence, and reverse transcription-polymerase chain reaction, respectively. Additionally, IHC was also used to detect the levels of GDNF, Rai, PI3K, and mTOR.
RESULTS:
The facial functional scores were significantly increased in the EA group than the FNI group (P<0.05 or P<0.01). HE staining showed nerve axons and myelin sheaths, which were destroyed immediately after the injury, were recovered with EA treatment. The expressions of Beclin-1 and LC3 were significantly elevated and the expression of P62 was markedly reduced in FNI rats (P<0.01); however, EA treatment reversed these abnormal changes (P<0.01). Meanwhile, EA stimulation significantly increased the levels of GDNF, Rai, PI3K, and mTOR (P<0.01). After exogenous administration with autophagy inhibitor 3-MA or GDNF antagonist, the repair effect of EA on facial function was attenuated (P<0.05 or P<0.01).
CONCLUSIONS
EA could promote the recovery of facial function and repair the facial nerve damages in a rat model of FNI. EA may exert this neuroreparative effect through mediating the release of GDNF, activating the PI3K/mTOR signaling pathway, and further regulating the autophagy of facial nerves.
Rats
;
Male
;
Animals
;
Rats, Sprague-Dawley
;
Electroacupuncture
;
Phosphatidylinositol 3-Kinase/metabolism*
;
Facial Nerve Injuries/therapy*
;
Phosphatidylinositol 3-Kinases/metabolism*
;
Beclin-1
;
Glial Cell Line-Derived Neurotrophic Factor
;
Signal Transduction
;
TOR Serine-Threonine Kinases/metabolism*
;
Autophagy
;
Mammals/metabolism*
8.Discovery of proqodine A derivatives with antitumor activity targeting NAD(P)H: quinone oxidoreductase 1 and nicotinamide phosphoribosyltransferase.
Jiangzhou SONG ; Guiqing ZOU ; Zhou ZHAO ; Ya ZHU ; Jiayu XUE ; Lanjia AO ; Huiyong SUN ; Haiping HAO ; Bo ZHANG ; Xiaowei XU
Chinese Journal of Natural Medicines (English Ed.) 2024;22(1):75-88
NAD(P)H: quinone oxidoreductase 1 (NQO1) is a flavin protease highly expressed in various cancer cells. NQO1 catalyzes a futile redox cycle in substrates, leading to substantial reactive oxygen species (ROS) production. This ROS generation results in extensive DNA damage and elevated poly (ADP-ribose) polymerase 1 (PARP1)-mediated consumption of nicotinamide adenine dinucleotide (NAD+), ultimately causing cell death. Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD+ salvage synthesis pathway, emerges as a critical target in cancer therapy. The concurrent inhibition of NQO1 and NAMPT triggers hyperactivation of PARP1 and intensive NAD+ depletion. In this study, we designed, synthesized, and assessed a novel series of proqodine A derivatives targeting both NQO1 and NAMPT. Among these, compound T8 demonstrated potent antitumor properties. Specifically, T8 selectively inhibited the proliferation of MCF-7 cells and induced apoptosis through mechanisms dependent on both NQO1 and NAMPT. This discovery offers a promising new molecular entity for advancing anticancer research.
Humans
;
NAD/metabolism*
;
Cell Line, Tumor
;
Reactive Oxygen Species/metabolism*
;
Nicotinamide Phosphoribosyltransferase/metabolism*
;
Cytokines/metabolism*
;
Quinones
;
Oxidoreductases
9.Effects of lncRNA-UCA1 targeting miR-204-5p on the proliferation, migration, apoptosis and immune escape of endometrial carcinoma cells.
Shuang JING ; Yan FENG ; Xiao Li HE ; Yue WANG
Chinese Journal of Oncology 2023;45(1):56-63
Objective: To investigate the effect of long non-coding RNA urothelial carcinoma-associated 1 (UCA1) gene on the proliferation, migration, apoptosis and immune escape of endometrial cancer cells and its molecular mechanism. Methods: Endometrial cancer tissues and adjacent normal tissues of patients with endometrioid adenocarcinoma who underwent total or partial hysterectomy in Henan Provincial People's Hospital from 2017 to 2019 were collected. The expressions of UCA1 and miR-204-5p were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and the cell proliferation, migration and apoptosis were detected by cell counting kit 8 (CCK8) method, Transwell method, flow cytometry, and dual-luciferase reporter assay was used to explore the target relationship between UCA1 and miR-204-5p. HEC-1A-sh-NC or HEC-1A-sh-UCA1 cells were co-cultured with peripheral blood mononuclear cells (PBMC) or cytokine-induced killer cells in vitro to explore the role of UCA1 in immune escape. Results: The expression level of UCA1 in endometrial cancer tissue (17.08±0.84) was higher than that in adjacent normal endometrial tissue (3.00±0.37), and the expression level of miR-204-5p (0.98±0.16) was lower than that in adjacent normal endometrial tissue (2.00±0.20, P<0.05). Pearson correlation analysis showed that the expression of miR-204-5p was negatively correlated with the expression of UCA1 (r=-0.330, P=0.030). The expressions of UCA1 and miR-204-5p were associated with the International Federation of Gynecology and Obstetrics stage of endometrial cancer, lymph node metastasis and vascular invasion (P<0.05). The relative ratio of absorbance (0.58±0.11) and the number of cell migration [(199.68±18.44)] in the sh-UCA1 group were lower than those in the sh-NC group (1.24±0.17 and 374.76±24.83), respectively. The apoptosis rate of sh-UCA1 group [(28.64±7.80)%] was higher than that of sh-NC group [(14.27±4.38)%, P<0.05]. After different ratios of effector cells and target cells were cultured, the cell survival rate of HEC-1A-sh-UCA1 group was lower than that of HEC-1A-sh-NC group, and the difference was statistically significant (P<0.05). UCA1 had a binding site for miR-204-5p. The relative ratio of absorbance (1.74±0.08) and the number of cell migration (426.00±18.00) cells in the UCA1+ anti-miR-204-5p group were higher than those in the control group [1.00±0.03 and (284.00±8.00) cells, respectively]. The apoptosis rate of UCA1+ anti-miR-204-5p group [(5.42±0.93)%] was lower than that of control group [(14.82±1.48)%, P<0.05]. HEC-1A-sh-UCA1 cells could induce higher interferon gamma (IFN-γ) expression when co-cultured with PBMC, and the levels of IFN-γ expression in PHA group and PHA+ pre-miR-204-5p group cells were 2.42±0.49 and 1.88±0.26, which were higher than that in the PHA+ pre-NC group (0.85±0.10, P<0.05). When co-cultured with cytokine-induced killer cells (different ratios) in vitro, the HEC-1A-sh-UCA1 group and the HEC-1A-pre-miR-204-5p group had lower survival rates than that in the HEC-1A-pre-miR-204-5p group. In the HEC-1A-pre-NC group, the differences were statistically significant (P<0.05). Conclusion: UCA1/miR-204-5p may play an important role in human endometrial cancer.
Female
;
Humans
;
MicroRNAs/metabolism*
;
RNA, Long Noncoding/genetics*
;
Leukocytes, Mononuclear
;
Carcinoma, Transitional Cell
;
Antagomirs
;
Cell Line, Tumor
;
Urinary Bladder Neoplasms
;
Cell Proliferation
;
Endometrial Neoplasms/genetics*
;
Apoptosis/genetics*
;
Cell Movement/genetics*
;
Gene Expression Regulation, Neoplastic
10.The expression and function of PD-L1 in CD133(+) human liver cancer stem-like cells.
Yu Di BAI ; Mao Lin SHI ; Si Qi LI ; Xiao Li WANG ; Jing Jing PENG ; Dai Jun ZHOU ; Fei Fan SUN ; Hua LI ; Chao WANG ; Min DU ; Tao ZHANG ; Dong LI
Chinese Journal of Oncology 2023;45(2):117-128
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

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