Research progress on the mechanism of microRNA regulation of cisplatin resistance in ovarian cancer / 国际肿瘤学杂志

Cisplatin resistance is an important factor in the poor treatment effect of ovarian cancer patients. MicroRNA (miRNA) can regulate cellular structural molecules, DNA repair, cell cycle, apoptosis and Wnt/β-catenin signaling pathway, autophagy, methylation and cancer stem cell, which are involved in the regulation of cisplatin resistance in ovarian cancer. Further understanding the mechanism of miRNA regulation of cisplatin resistance in ovarian cancer will help find new treatment options to optimize existing treatment plans and improve efficacy.

Research advances in second-line therapies for hepatocellular carcinoma after resistance to targeted therapy combined with immunotherapy / 临床肝胆病杂志

In recent years， clinical studies on targeted therapy and immunotherapy for advanced hepatocellular carcinoma used alone or in combination have provided abundant evidence on efficacy and safety for the selection of first-line therapies. However， no consensus has been reached on the selection of second-line therapies in various clinical guidelines for hepatocellular carcinoma， which is caused by the fact that existing evidence is limited to the options after failure of sorafenib and that there is still a lack of high-level evidence for new first-line therapies such as second-line therapies after resistance to targeted therapy and immunotherapy for hepatocellular carcinoma. This article reviews the results of current clinical trials and summarizes the studies on second-line therapies for hepatocellular carcinoma after resistance to first-line targeted therapy and immunotherapy for hepatocellular carcinoma based on the different mechanisms of action of drugs， as well as the research advances in recent years. For hepatocellular carcinoma patients with resistance to first-line targeted therapy and immunotherapy， targeted combination therapy and dual-immune therapy are expected to improve treatment outcome and survival， and more prospective clinical studies are needed in the future to provide effective and safe treatment regimens for hepatocellular carcinoma patients with resistance to targeted therapy and immunotherapy.

Functional and related research progress of γ-glutamyltransferase 1 / 中国医师杂志

Gamma glutamyltransferase 1 (GGT1) is involved in regulating processes such as redox, cell proliferation, tumor metastasis, and drug resistance, and is abnormally expressed in various tumors such as prostate cancer and clear cell renal cell carcinoma. This article summarizes the expression and role of GGT1 in various diseases, providing new ideas for further exploration of treatment strategies for GGT1 related diseases.

Research progress of Nrf2 in ovarian cancer / 国际肿瘤学杂志

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important transcription factor that regulates redox, lipid metabolism and protein dynamic balance, and plays an important role in protecting the body from oxidative stress damage. Recently, more and more studies have shown that Nrf2 is activated in ovarian cancer by various mechanisms to induce increased antioxidant enzymes, change sex hormone metabolism and induce downstream targets. Further studying the mechanism of Nrf2 in promoting the development of ovarian cancer, exploring its role in drug resistance and seeking new therapeutic targets can provide new ideas for the treatment of drug-resistant ovarian cancer.

Research progress of NADPH oxidase 2 in malignant tumors / 国际肿瘤学杂志

Reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2) acts as a source of reactive oxygen species, which participates in and influences normal physiological function of human body. Nowadays, many studies have found that Nox2 is related to prognosis of patients, drug resistance and molecular targeted therapy in various malignant tumors, such as acute myeloid leukemia, gastric cancer, colorectal cancer, ovarian cancer, lung cancer and esophageal cancer. What's more, it may be a novel biomarker and a potential therapeutic target for malignant tumors.

Progress of mechanisms of osimertinib resistance and coping strategies in non-small cell lung cancer / 肿瘤研究与临床

Osimertinib, the third generation of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has demonstrated notable clinical benefit in the targeted therapy for patients with non-small cell lung cancer (NSCLC). However, the development of drug resistance is an inevitable challenge. In order to tackle this issue, ongoing efforts are being made to develop new generations of targeted drugs and treatment strategies, some of which are already undergoing clinical trials. This article aims to review the current research on the mechanisms of osimertinib resistance and outline the advancements made in post-drug resistance treatment strategies.

Establishment and preliminary application of organoids in ovarian cancer / 中华妇产科杂志

Objective:To explore the establishment and application of ovarian cancer organoids.Methods:Fresh ovarian tumor tissues, obtaining from patients underwent surgery in the First Affiliated Hospital of Nanjing Medical University between October 2021 and March 2022, were collected, enzymatic degraded, digested, and embedded into matrigel to establish organoids. A total of 32 ovarian cancer samples were collected. Hematoxylin eosin (HE) staining and immunofluorescence (IF) procedure were used to verify the morphological structure of organoids and their expression of molecular markers. 3D cyto-live or dead assay was used to detecte the live or dead cells in organoids. Carboplatin with a concentration ranging from 5 to 80 μmol/L (5, 10, 20, 40, 80 μmol/L) was added to organoids to calculate the 50% inhibitory concentration (IC 50) in different organoids. Results:(1) Organoids from a total of 32 patients were established, of which 18 cases could be passaged stably in the long term in vitro, while 14 could be passaged in the short time. The average amplification time of long-term passage in vitro was over 3 months, and the longest reached 9 months. (2) In HE staining, significant nuclei atypia and local micropapillary structures were observed in organoids. IF staining revealed that ovarian cancer organoids expressed molecular markers similar to primary tumor tissues, such as Pan cytokeratin (Pan-CK), p53, paired box gene 8 (PAX8), and Wilms tumor gene 1 (WT1). (3) In 3D cyto-live or dead assay, a large number of apoptotic cells were observed inside and around the organoids after added carboplatin. The sensitivity to carboplatin varied in 18 organoids could amplify in the long term, with an average IC 50 of (29.5±15.8) μmol/L. Moreover, IC 50 values of 4 organoids derived from patients received neoadjuvant chemotherapy were much higher than the 14 organoids which did not received neoadjuvant chemotherapy [(48.7±11.3) μmol/L vs (24.0±12.1) μmol/L; t=3.429, P=0.022]. Conclusions:Organoids recapitulate ovarian cancers in vitro and could be stably passaged. Organoids derived from patients received neoadjuvant chemotherapy have higher resistance to carboplatin.

Research progress on the role of non-coding RNA in chemotherapy resistance of osteosarcoma / 中华骨科杂志

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. With the emergence of chemotherapy resistance in recent years, the survival rate of osteosarcoma patients has reached a bottleneck. Therefore, exploration of its chemoresistance mechanism is one of the popular research directions currently. Non-coding RNA (ncRNA) is a class of RNA without the ability to encode proteins, which is classified into microRNA, long non-coding RNA, and circular RNA based on length and shape. With the development of high-throughput sequencing technology, there is increasing evidence that some non-coding RNAs are abnormally upregulated or downregulated in osteosarcoma cells and affect the response of osteosarcoma to four commonly used chemotherapeutic drugs (methotrexate, doxorubicin, cisplatin and ifosfamide) through mechanisms such as regulation of apoptosis, cell cycle, signaling pathways, intracellular drug concentration, and cellular autophagy. Therefore, thesenon-coding RNAs are expected to be novel targets for osteosarcoma treatment. In this paper, the current studies were searched and reviewed on the above three non-coding RNAs mediating chemoresistance in osteosarcoma, aiming to provide a reference for breaking the bottleneck of survival rate of osteosarcoma patients.

Expression of p21-activated kinase 2 in laryngeal squamous cell carcinoma and its correlation with clinicopathological characteristics and chemosensitivity / 肿瘤研究与临床

Objective:To investigate the expression of p21-activated kinase 2 (PAK2) in laryngeal squamous cell carcinoma and its relationship with the clinicopathological characteristics and chemosensitivity of patients.Methods:Transcriptome sequencing (RNA-seq) data for laryngeal squamous cell carcinoma were downloaded from the Cancer Genome Atlas (TCGA) database, and 123 patients were included in the study (12 cases had cancer tissues and normal tissues data, and the remaining 111 only had cancer tissues data). Differential expression of PAK2 in cancer and para-cancer tissues was analyzed by using R software, and the potential function of PAK2 in laryngeal squamous cell carcinoma was investigated by using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database signaling pathway enrichment. A total of 34 patients with primary laryngeal squamous cell carcinoma tissues and corresponding para-carcinoma 34 tissue specimens who underwent surgical resection were retrospectively selected from Chaoyang Central Hospital between April 2016 and June 2021, and 20 cases of normal laryngeal mucosa tissues were selected as the controls. Immunohistochemistry was used to detect the expression of PAK2 in various tissues, and its correlation with clinicopathological factors was analyzed. A total of 35 supraglottic primary laryngeal squamous cell carcinoma patients were retrospectively collected before induction chemotherapy during the same period, including 20 patients sensitive to chemotherapy and 15 patients resistant to chemotherapy. Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to detect the relative expression level of PAK2 mRNA in cancer tissues.Results:Analysis of TCGA database data showed that PAK2 expression was increased in cancer tissues compared with that in para-cancer tissues ( P = 0.012); KEGG database signaling pathways showed that the high expression of PAK2 in laryngeal squamous cell carcinoma was related to signal transduction pathways, cell cycle, and cancer. Immunohistochemistry showed that the proportion of PAK2 positive in 34 cases of laryngeal squamous cell carcinoma tissues was higher than that in adjacent tissues and normal tissues [58.82% (20/34) vs. 0.03% (1/34), 0 (0/20), all P < 0.001]. There were statistically significant differences in the proportion of PAK2 positive patients stratified with different degrees of differentiation [high differentiation vs. low or middle differentiation: 33.33% (6/18)vs. 87.50% (14/16)], lymph node metastasis [presence vs. absence: 90.91% (10/11) vs. 43.48% (10/23)], TNM staging [stage Ⅲ-Ⅳ vs. stage Ⅰ-Ⅱ: 82.35% (14/17) vs. 35.29% (6/17)] (all P < 0.05), and PAK2 positive patients were not associated with clinical type, tumor size, smoking history, drinking history, and age (all P > 0.05). qRT-PCR showed that the relative expression level of PAK2 mRNA in the chemotherapy-resistant group was higher than that in the chemotherapy-sensitive group (3.89±0.12 vs. 0.78±0.23, P < 0.001). Conclusions:The expression level of PAK2 in laryngeal squamous cell carcinoma tissues is increased, and the high expression of PAK2 is closely related to the malignant clinical characteristics of patients with laryngeal squamous cell carcinoma. The high expression of PAK2 may indicate the insensitivity to traditional chemotherapy regimens, and PAK2 may be a potential gene that targets and regulates the chemosensitivity of laryngeal squamous cell carcinoma.

Effect of miR-144-3p targeting Nrf2 on cisplatin sensitivity in bladder cancer / 中国医师杂志

Objective:To investigate the role of miR-144-3p in cisplatin resistance of bladder cancer.Methods:Bladder cancer T24 cells were cultured in vitro and divided into blank group (untreated), mimetic control group, miR-144-3p mimetic transfection group, inhibitor control group, and miR-144-3p inhibitor transfection group. Real time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to verify the transfection effect, methyl thiazolyl tetrazolium (MTT) method was used to detect the survival rate of cells treated with cisplatin in each group, and Western blot was used to detect the expression of the target protein. The targeting relationship between miR-144-3p and nuclear factor E2 related factor 2 (Nrf2) was validated using dual fluorescence reporter gene experiments. Furthermore, Nrf2 was knocked out in each group of cells, and the mRNA and protein expression levels of HO-1, Bcl-2, and Caspase-3 were detected by qRT-PCR and Western blot in each group of cells.Results:Compared with the control group, bladder cancer cells in the miR-144-3p mimetic transfection group were more sensitive to cisplatin, while the miR-144-3p inhibitor transfection group had the opposite effect; The miR-144-3p simulant transfection group can effectively inhibit the mRNA and protein expression level of Nrf2 in bladder cancer cells (all P<0.05), while the miR-144-3p inhibitor transfection group can up regulate the mRNA and protein level of Nrf2 (all P<0.05). The miR-144-3p mimetic transfection group showed significant downregulation of mRNA and protein expression of HO-1 and Bcl-2, while the expression of Caspase-3 was upregulated (all P<0.05), while the miR-144-3p inhibitor transfection group showed the opposite results. The luciferase results confirmed that miR 144 3p can directly bind to the 3′- UTR region of Nrf2, reducing the mRNA level of Nrf2. When Nrf2 was knocked out, whether miR-144-3p mimetic transfection group or miR-144-3p inhibitor transfection group, the mRNA and protein expression levels of HO-1, Bcl-2 and Caspase-3 did not change significantly, and miR-144-3p lost the ability to regulate the cisplatin sensitivity of bladder cancer cells. Conclusions:miR-144-3p targets to regulate the sensitivity of Nrf2 to cisplatin in bladder cancer, and miR-144-3p is expected to become a new target for the treatment of cisplatin resistant or refractory bladder cancer.

Research progress in reversing multidrug resistance in colorectal cancer / 国际肿瘤学杂志

Multidrug resistance impacts negatively upon the curative effect of chemotherapy and prognosis in colorectal cancer. There is a growing body of studies trying to develop drugs to overcome multidrug resistance against its common targets, including ATP-binding cassette proteins, metabolic enzymes, apoptotic genes, signaling pathways and genetic material, among which P-glycoprotein inhibitors and drugs disrupting DNA are deeply developed. Developing new inhibitors or combining existing inhibitors with conventional treatment are hopeful ways to overcome multidrug resistance in colorectal cancer.

Status and significance of BCR-ABL1 kinase domain mutations in imatinib-resistant chronic myelogenous leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia patients from Northeast China / 白血病·淋巴瘤

Objective:To explore the characteristics of BCR-ABL1 kinase domain mutations in imatinib-resistant chronic myelogenous leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL) patients from Northeast China and their impact on prognosis. Methods:The clinical data of 252 CML patients and 49 Ph + ALL patients who were admitted to the First Hospital of Jilin University from January 2013 to October 2018 were retrospectively analyzed. The samples of bone marrow or peripheral blood were collected from patients when imatinib treatment was not effective. Nested polymerase chain reaction (PCR) was used to amplify the BCR-ABL1 kinase domain, and Sequencing Analysis v5.4 software was used to analyze the mutation of BCR-ABL1 kinase domain. Patients were followed up for 6-48 months, and the survival analysis was performed. Results:Among 252 CML patients, the mutations in ABL1 kinase domain were found in 57 patients (22.6%), including 25 patients in the chronic phase, 21 patients in the accelerated phase and 11 patients in the blast crisis; 50 patients had 20 types of single point mutation, and the most common mutation types were E255K (16.0%, 8/50), T315I (14.0%, 7/50), M244V (8.0%, 4/50) and G250E (8.0%, 4/50), which were all concentrated in the P-loop and C-helix domains; 7 patients had double mutations; patients with multiple mutations had the worst prognosis, with a median overall survival (OS) time of 3.2 months. Among 49 Ph + ALL patients, 17 cases (34.7%) were positive for mutations in the BCR-ABL1 kinase domain, 14 patients had 12 types of single point mutation, and 3 patients had multiple mutations; the median OS time of patients with multiple mutations, mutations located in the P-loop and C-helix domains and mutations located in the other domains was 2.0, 8.0 and 18.0 months, and the difference in OS among the three groups was statistically significant ( P < 0.01). Conclusions:Among the imatinib-resistant CML and Ph + ALL patients from Northeast China, point mutations in the P-loop and C-helix domains are most commonly found. Multiple mutations, mutations in the P-loop and C-helix domains are related to the poor prognosis of the patients.

Progress in molecular resistance mechanisms of targeted therapy for chronic myeloid leukemia / 白血病·淋巴瘤

Resistance or drug-resistant recurrence of targeted tumor therapy is a complex and multi-factorial process, with the final result of tumor clones that can evade treatment or have relative proliferation advantages under treatment pressure being selectively retained. The BCR::ABL1 fusion gene is the primary molecular abnormality of chronic myeloid leukemia (CML), and the development and application of tyrosine kinase inhibitors (TKI) targeting the BCR::ABL1 fusion protein pioneered the era of small molecule targeted therapeutics. Several TKI have been approved for clinical application or in development. Although most CML patients manifest an excellent response to TKI treatment, there are still some patients with poor primary response or relapse with drug resistance. With the increase in the number of patients with long-term maintenance therapy and the sequential use of multiple TKI, the resistance of TKI has become more complicated. This article introduces the research progress of CML molecular resistance mechanisms in recent years and shares the relevant cutting-edge reports at the 63rd American Society of Hematology Annual Meeting in 2021.

Effects of autophagy-mediated crizotinib resistance on cancer stem-like cell subsets in anaplastic lymphoma kinase-positive anaplastic large cell lymphoma and its significance / 白血病·淋巴瘤

Objective:To investigate the effects of autophagy-mediated crizotinib resistance on cancer stem-like cell subsets in anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALK + ALCL). Methods:The preliminary research of our group divided ALK + ALCL Karpas299 cell line into two subgroups: reporter unresponsive (RU) and reporter responsive (RR) cells through the implantation of Sox2 reporter genes, among which the RR cells had the characteristics of stem cells. Fluorescent labeled LC3 overexpressing RR and RU cells (RR-LC3 and RU-LC3) were constructed by lentiviral transfection technique, and the transfection efficiency was verified by using Western blotting and flow cytometry. RU-LC3 and RR-LC3 were treated with crizotinib at different concentrations (0, 250, 500, 1 000 nmol/L). The RED and GEN signals were detected by using double-signal flow cytometry to observe autophagy flux (RED represents the red signal B695 of the next generation of far-red fluorescent protein TagFP635 mKate; GEN represents the green signal from pH-sensitive GFP variant pHluorin B530), and the RED to GEV ratio represents autophagy flux. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect autophagy related genes ULK1, WIPI1 and LC3B mRNA expression levels in cells. The effects of different concentrations of crizotinib (250, 500, 1 000 nmol/L) combined with chloroquine (5, 10 μmol/L) on the cell survival were detected by using MTS assay. Results:RU-LC3 and RR-LC3 cells with overexpression of LC3 were successfully constructed. After induction of 250, 500 and 1 000 nmol/L crizotinib, the RED to GEN ratio in RU-LC3 cells was 1.135±0.017, 1.453±0.017 and 1.755±0.021, respectively; the RED to GEN ratio in RR-LC3 cells was 1.193±0.018, 2.116±0.013 and 3.307±0.189, respectively; the RED to GEN ratio in RU-LC3 cells and RR-LC3 cells showed a dose-dependent manner. The RED to GEN ratio in RR-LC3 cells was higher than that in RU-LC3 cells when treated with same concentrations of crizotinib, and the differences were statistically significant (all P < 0.01). The autophagy flux of RR-LC3 cells was larger than that of RU-LC3 cells. When treated without crizotinib, mRNA relative expression levels of ULK1, WIPI1 and LC3B in RR cells were higher than those in RU cells (1.69±0.05 vs.1.01±0.02, t = -1.62, P < 0.01; 1.24±0.04 vs. 1.03±0.05, t = -2.11, P < 0.01; 1.70±0.22 vs. 1.02±0.05, t = -1.74, P = 0.033). In the absence of chloroquine, the half-inhibitory concentration ( IC50) of crizotinib in RR cells was higher than that of RU cells (950 nmol/L vs. 709 nmol/L). After treated with chloroquine, IC50 of RU cells did not change, while IC50 of RR cells was decreased with the increase of chloroquine concentration. Conclusions:Compared with RU cells, autophagy reaction of cancer stem-like RR cells is more rapid and intense, which is considered to be one of the important reasons for their resistance to crizotinib.

Role of thioredoxin reductase 1 in multidrug resistance caused by reactive oxygen species-related cell apoptosis in hepatocellular carcinoma / 临床肝胆病杂志

Objective Drug resistance is the main cause of chemotherapy failure in hepatocellular carcinoma (HCC), and thioredoxin reductase 1 (TXNRD1), as a major influencing factor for reactive oxygen species (ROS) metabolism, has been proven to be associated with the poor prognosis of patients with HCC. This study aims to explore the role of TXNRD1 in the mechanism of multidrug resistance in HCC. Methods BEL/FU cells in BEL-7402 cell line were selected as the multidrug-resistant cell line. The siRNA was used for the intervention of TXNRD1 expression; quantitative real-time PCR and Western blotting were used to measure the expression of TXNRD1; CCK-8 assay and flow cytometry were used to evaluate the effect of TXNRD1 on hepatocyte ROS accumulation, resistance to 5-fluorouracil (5-Fu) and doxorubicin (DOX), and apoptosis in vitro; a xenograft tumor model was established to investigate the effect of auranofin (AUR) on drug resistance in vivo. The two-independent-samples t test was used for comparison of continuous data between two groups. Results As a multidrug-resistant HCC cell line, BEL/Fu showed high mRNA and protein expression levels of TXNRD1 (both P < 0.05). Compared with 5-Fu or DOX treatment alone, the TXNRD1 inhibitor AUR combined with 5-Fu or DOX had had a significant reduction in the number of colony formation ( P < 0.01) and a significant increase in apoptosis ratio ( P < 0.001). The ROS scavenger N-acetylcysteine (NAC) significantly weakened the effect of TXNRD1 knockdown by siRNA on the drug resistance of BEL/Fu cells, and the application of NAC effectively reduced the apoptosis ratio of cells after siRNA interference ( P < 0.001). Animal experiments also confirmed that compared with the nude mice treated with 5-Fu alone, the nude mice treated with 5-Fu and AUR had a significantly lower tumor mass ( P < 0.001) and a significantly smaller tumor volume ( P < 0.001). Conclusion TXNRD1 plays an important role in the drug resistance of HCC, and inhibition of its level in cells can effectively improve drug resistance. As a TXNRD1 inhibitor, AUR has great application prospects in the multimodality therapy for HCC.

Progress of epidermal growth factor receptor-tyrosine kinase inhibitor targeted therapy in Chinese patients with non-small cell lung cancer / 肿瘤研究与临床

Cell epidermal growth factor receptor (EGFR) mutation is one of the causes of non-small cell lung cancer (NSCLC). The emergence of targeted drugs for EGFR gene mutation provides a new direction for NSCLC treatment. The common EGFR-targeted drugs like the first-generation gefitinib and erlotinib, the second-generation afatinib and the third-generation osimertinib have shown their good efficacies in a number of large international clinical trials. EGFR gene mutation in Chinese NSCLC patients is different from that in European and American NSCLC patients. This paper briefly reviews the characteristics of EGFR gene mutation and the current status and progress of EGFR-targeted drugs in Chinese NSCLC patients to investigate the mutation characteristics of EGFR in Chinese NSCLC patients and the response as well as prognosis of Chinese patients to EGFR-TKI therapy.

Ibrutinib in treatment of steroid-resistant chronic graft-versus-host disease: report of 3 cases and review of literature / 白血病·淋巴瘤

Objective:To investigate the clinical characteristics of steroid-resistant chronic graft-versus-host disease (cGVHD) patients and the therapeutic effect of ibrutinib.Methods:The clinical data of 3 steroid-resistant cGVHD patients treated with ibrutinib after allogeneic hematopoietic stem cell transplantation in the First Affiliated Hospital of Soochow University from December 2017 to March 2018 were retrospectively analyzed, and the literature was reviewed.Results:All 3 patients had different degrees of skin and oral cGVHD. One patient's oral symptom improved after the application of prednisone, and the skin symptom was better after oral ibrutinib; one patient's oral symptom improved after oral ibrutinib, but skin symptom did not improve significantly; one patient's skin symptom did not improve significantly. None of the 3 patients presented with adverse reactions such as hemorrhage, infection and cytopenia.Conclusions:Ibrutinib has a certain effect on the improvement of symptoms in steroid-resistant cGVHD patients.

The effect of miR-485-5p on cisplatin resistance of colon cancer cells / 中华老年医学杂志

Objective:To investigate the effect of miR-485-5p on cisplatin resistance of colon cancer cells through the PI3K/Akt-PAK1 signaling pathway.Methods:The LoVo/DDP cell lines were constructedand divided into an NC group(without transfection treatment), an miR-485-5p mimics group(transfected with miR-485-5p mimics), an miR-485-5p inhibitors group(transfected with miR-485-5p inhibitors), an IPA-3 group(intervention with IPA-3)and an miR-485-5p mimics+ IPA-3 group(transfection with miR-485-5p mimics andinterventionwith IPA-3), with all given 0, 3, and 5 μmol/L cisplatin treatment.Results:Among the 20 patients, the proportion of negative miR-485-5p detection was 85.0%(17/20), and the proportion of positive detection was 15.0%(3/20); the proportion of negative PAK1 detection was 20.0%(4/20), and the proportion of positive detection was 80.0%(16/20). The expression of miR-485-5p in colon cancer tissue was significantly lower than that in adjacent tissues( P<0.05); the expression of miR-485-5p in the human colon cancer cell lines LoVo, SW620, HCT116, and SW480 was all lower than in normal intestinal mucosal cells( P<0.05); the expression of miR-485-5p in LoVo/DDP was significantly lower than inLoVo( P<0.001). Under the action of 3 μmol/L and 5 μmol/L cisplatin, LoVo/DDP had highercell viability but a lower apoptosis rate than LoVo( P<0.001). The cell survival rate in the miR-485-5p mimics group was significantly lower than that in the miR-485-5p inhibitors group( P<0.001). Compared with the NC mimics group, overexpression of miR-485-5p significantly down-regulated luciferase activity of the wild-type PAK1 reporter gene( P<0.001); P-PI3k, P-Akt and PAK1levels in the miR-485-5p mimics group were significantly lower than in the miR-485-5p inhibitors group( P<0.001); the cell survival rate in the miR-485-5p mimics group, the IPA-3 group and the miR-485-5p mimics+ IPA-3 group was significantly lower than in the NC group( P<0.001)and the cell survival rate in the miR-485-5p mimics+ IPA-3 group was significantly lower than in the miR-485-5p mimics group( P<0.001). Conclusions:Up-regulation of miR-485-5p reverses colon cancer cisplatin resistance through the PI3K/Akt-PAK1signaling pathway, suggesting that overexpression of miR-485-5p or inhibition of the PI3K/Akt-PAK1signaling pathway enhances the therapeutic efficacy of cisplatin in colon cancer.

Effects of hyperthermia on biological behavior of human laryngeal cancer Hep-2 cisplatin-resistant cell line / 肿瘤研究与临床

Objective:To investigate the effects of hyperthermia on the biological behavior of human laryngeal cancer Hep-2 cisplatin-resistant (Hep-2/CDDP) cell line and its possible mechanism.Methods:Hep-2/CDDP cell line was induced by high impact combined with increasing concentration method. Cell count method was used to detect the cell proliferation ability of Hep-2 parental cell group (Hep-2 cells without cisplatin-resistance and the cells were cultured with RPMI 1640 cultured medium without cisplatin), Hep-2/CDDP cell group and Hep-2/CDDP+cisplatin group (using RPMI 1640 cultured medium including 4 mg/L cisplatin). Hep-2/CDDP cell group and Hep-2 parental cell group were treated with cultured medium including 0, 0.004, 0.04, 0.4, 4, 40 mg/L cisplatin, respectively. The sensitivity of Hep-2/CDDP cells to cisplatin, vincristine and 5-fluorouracil was determined by using methyl thiazolyl tetrazolium (MTT) method. The half inhibitory concentration ( IC50) and resistance index (RI) were also calculated. Hep-2/CDDP cell group was divided into 4 subgroups: the cells in the control group were cultured for 24 h at 37 ℃; the cells in hyperthermia group were treated at 43 ℃ for 2 h and then re-cultured at 37 ℃ for 22 h; the cells in cisplatin group were cultured at 37 ℃ for 24 h in cultured medium containing 4 mg/L cisplatin. The cells in hyperthermia combined with cisplatin group were cultured in cultured medium containing 4 mg/L cisplatin, treated at 43 ℃ for 2 h and then re-cultured at 37 ℃ for 22 h. The effects of hyperthermia combined with cisplatin on the proliferation and early apoptosis of Hep-2/CDDP cells were detected by using MTT and flow cytometry. The interaction of hyperthermia combined with cisplatin on the proliferation and early apoptosis of HEP-2/CDDP cells was observed by using factorial analysis. Western blotting was used to detect the effect of hyperthermia combined with cisplatin on the expressions of wild-type p53 and PI3K in Hep-2/CDDP cells. Hep-2/CDDP cells were divided into 4 groups: the control group (Hep-2/CDDP cells were cultured for 24 h at 37 ℃); chemotherapy group was treated with 12 mg/L vincristine or 9 mg/L 5-fluorouracil; in the hyperthermia group, Hep-2/CDDP cells were treated at 43℃ for 2 h and then re-cultured at 37 ℃ for 22 h; in hyperthermia combined with chemotherapy group, the cells were cultured in a medium containing 12 mg/L vincristine or 9 mg/L 5-fluorouracil, treated at 43 ℃ for 2 h and then re-cultured at 37 ℃ for 22 h. MTT method was used to detect the effect of hyperthermia combined with vincristine and 5-fluorouracil on the proliferation of Hep-2/CDDP cells. Results:Hep-2/CDDP cell line was successfully established. There were no significant differences in the number of cells in Hep-2/CDDP cell group, Hep-2 parental cell line group and Hep-2/CDDP + cisplatin cell group at different time points (all P > 0.05), and the doubling time was 43.8, 40.6 and 43.5 h, respectively. The IC50 of Hep-2 parental cell line group and Hep-2/CDDP cell group to cisplatin was 4.771 mg/L and 42.749 mg/L, respectively, and the RI was 8.960. Hyperthermia combined with cisplatin could inhibit the proliferation of Hep-2/CDDP cells ( F = 327.91, P < 0.05) and promote the early apoptosis of Hep-2/CDDP cells ( F = 724.63, P < 0.05). Factorial analysis showed that hyperthermia combined with cisplatin had an interaction effect on the proliferation and early apoptosis of Hep-2/CDDP cells ( F = 185.68, 472.51, all P < 0.05). Western blotting showed that the relative expression levels of wild-type p53 protein and PI3K protein in the control group, hyperthermia group, cisplatin group and hyperthermia combined with cisplatin group were significantly different ( F = 547.76, 404.44, all P < 0.01). Hyperthermia combined with vincristine or 5-fluorouracil could inhibit the proliferation of Hep-2/CDDP cells ( F = 33.06, 34.61, all P < 0.05). Factorial analysis showed that hyperthermia combined with vincristine and 5-fluorouracil had no interaction effect on the proliferation of Hep-2/CDDP cells ( F = 0.64,0.60, all P > 0.05). Conclusions:Hyperthermia may reverse the resistance of Hep-2/CDDP cell line to cisplatin by upregulating wild-type p53 expression and inhibiting the PI3K pathway. Hep-2/CDDP cell line has cross-resistance to vincristine and 5-fluorouracil. Hyperthermia can increase the sensitivity of Hep-2/CDDP cell line to vincristine and 5-fluorouracil.

Progress of Fibulin protein family in tumor development, progression and chemotherapy resistance / 肿瘤研究与临床

Fibulin protein family is a class of extracellular matrix (ECM) proteins that are widely expressed in various tissues and plays an important role in the formation and stabilization of ECM. More and more studies have found that Fibulin protein family can play a role in tumor suppression or tumor promotion in different tumor tissues, which affects tumor proliferation, invasion and metastasis and is closely related to tumor chemotherapy resistance. Furthermore, Fibulin protein family is expected to be the target of inhibiting and reversing tumor chemotherapy resistance. This article reviews the role, target and molecular mechanism of Fibulin protein family in tumor development, progression and chemotherapy resistance, aiming to find a new research direction for tumor chemotherapy resistance.