HMGA1 sensitizes esophageal squamous cell carcinoma to mTOR inhibitors through the ETS1-FKBP12 axis.

Esophageal carcinoma is amongst the prevalent malignancies worldwide, characterized by unclear molecular classifications and varying clinical outcomes. The PI3K/AKT/mTOR signaling, one of the frequently perturbed dysregulated pathways in human malignancies, has instigated the development of various inhibitory agents targeting this pathway, but many ESCC patients exhibit intrinsic or adaptive resistance to these inhibitors. Here, we aim to explore the reasons for the insensitivity of ESCC patients to mTOR inhibitors. We assessed the sensitivity to rapamycin in various ESCC cell lines by determining their respective IC50 values and found that cells with a low level of HMGA1 were more tolerant to rapamycin. Subsequent experiments have supported this finding. Through a transcriptome sequencing, we identified a crucial downstream effector of HMGA1, FKBP12, and found that FKBP12 was necessary for HMGA1-induced cell sensitivity to rapamycin. HMGA1 interacted with ETS1, and facilitated the transcription of FKBP12. Finally, we validated this regulatory axis in in vivo experiments, where HMGA1 deficiency in transplanted tumors rendered them resistance to rapamycin. Therefore, we speculate that mTOR inhibitor therapy for individuals exhibiting a reduced level of HMGA1 or FKBP12 may not work. Conversely, individuals exhibiting an elevated level of HMGA1 or FKBP12 are more suitable candidates for mTOR inhibitor treatment.

Efficacy and safety of perioperative therapy for locally resectable gastric cancer: A network meta-analysis of randomized clinical trials.

BACKGROUND: Gastric cancer (GC) is the fifth most commonly diagnosed malignancy worldwide, with over 1 million new cases per year, and the third leading cause of cancer-related death. AIM: To determine the optimal perioperative treatment regimen for patients with locally resectable GC. METHODS: A comprehensive literature search was conducted, focusing on phase II/III randomized controlled trials (RCTs) assessing perioperative chemotherapy and chemoradiotherapy in treating locally resectable GC. The R0 resection rate, overall survival (OS), disease-free survival (DFS), and incidence of grade 3 or higher nonsurgical severe adverse events (SAEs) associated with various perioperative regimens were analyzed. A Bayesian network meta-analysis was performed to compare treatment regimens and rank their efficacy. RESULTS: Thirty RCTs involving 8346 patients were included in this study. Neoadjuvant XELOX plus neoadjuvant radiotherapy and neoadjuvant CF were found to significantly improve the R0 resection rate compared with surgery alone, and the former had the highest probability of being the most effective option in this context. Neoadjuvant plus adjuvant FLOT was associated with the highest probability of being the best regimen for improving OS. Owing to limited data, no definitive ranking could be determined for DFS. Considering nonsurgical SAEs, FLO has emerged as the safest treatment regimen. CONCLUSION: This study provides valuable insights for clinicians when selecting perioperative treatment regimens for patients with locally resectable GC. Further studies are required to validate these findings.

Multifaceted role of microRNAs in gastric cancer stem cells: Mechanisms and potential biomarkers.

MicroRNAs (miRNAs) have received much attention in the past decade as potential key epigenomic regulators of tumors and cancer stem cells (CSCs). The abnormal expression of miRNAs is responsible for different phenotypes of gastric cancer stem cells (GCSCs). Some specific miRNAs could be used as promising biomarkers and therapeutic targets for the identification of GCSCs. This review summarizes the coding process and biological functions of miRNAs and demonstrates their role and efficacy in gastric cancer (GC) metastasis, drug resistance, and apoptosis, especially in the regulatory mechanism of GCSCs. It shows that the overexpression of onco-miRNAs and silencing of tumor-suppressor miRNAs can play a role in promoting or inhibiting tumor metastasis, apart from the initial formation of GC. It also discusses the epigenetic regulation and potential clinical applications of miRNAs as well as the role of CSCs in the pathogenesis of GC. We believe that this review may help in designing novel therapeutic approaches for GC.

Research progress of Paris polyphylla in the treatment of digestive tract cancers.

Cancer has become one of the most important causes of human death. In particular, the 5 year survival rate of patients with digestive tract cancer is low. Although chemotherapy drugs have a certain efficacy, they are highly toxic and prone to chemotherapy resistance. With the advancement of antitumor research, many natural drugs have gradually entered basic clinical research. They have low toxicity, few adverse reactions, and play an important synergistic role in the combined targeted therapy of radiotherapy and chemotherapy. A large number of studies have shown that the active components of Paris polyphylla (PPA), a common natural medicinal plant, can play an antitumor role in a variety of digestive tract cancers. In this paper, the main components of PPA such as polyphyllin, C21 steroids, sterols, and flavonoids, amongst others, are introduced, and the mechanisms of action and research progress of PPA and its active components in the treatment of various digestive tract cancers are reviewed and summarized. The main components of PPA have been thoroughly explored to provide more detailed references and innovative ideas for the further development and utilization of similar natural antitumor drugs.

HMGA1 drives chemoresistance in esophageal squamous cell carcinoma by suppressing ferroptosis.

Chemotherapy is a primary treatment for esophageal squamous cell carcinoma (ESCC). Resistance to chemotherapeutic drugs is an important hurdle to effective treatment. Understanding the mechanisms underlying chemotherapy resistance in ESCC is an unmet medical need to improve the survival of ESCC. Herein, we demonstrate that ferroptosis triggered by inhibiting high mobility group AT-hook 1 (HMGA1) may provide a novel opportunity to gain an effective therapeutic strategy against chemoresistance in ESCC. HMGA1 is upregulated in ESCC and works as a key driver for cisplatin (DDP) resistance in ESCC by repressing ferroptosis. Inhibition of HMGA1 enhances the sensitivity of ESCC to ferroptosis. With a transcriptome analysis and following-up assays, we demonstrated that HMGA1 upregulates the expression of solute carrier family 7 member 11 (SLC7A11), a key transporter maintaining intracellular glutathione homeostasis and inhibiting the accumulation of malondialdehyde (MDA), thereby suppressing cell ferroptosis. HMGA1 acts as a chromatin remodeling factor promoting the binding of activating transcription factor 4 (ATF4) to the promoter of SLC7A11, and hence enhancing the transcription of SLC7A11 and maintaining the redox balance. We characterized that the enhanced chemosensitivity of ESCC is primarily attributed to the increased susceptibility of ferroptosis resulting from the depletion of HMGA1. Moreover, we utilized syngeneic allograft tumor models and genetically engineered mice of HMGA1 to induce ESCC and validated that depletion of HMGA1 promotes ferroptosis and restores the sensitivity of ESCC to DDP, and hence enhances the therapeutic efficacy. Our finding uncovers a critical role of HMGA1 in the repression of ferroptosis and thus in the establishment of DDP resistance in ESCC, highlighting HMGA1-based rewiring strategies as potential approaches to overcome ESCC chemotherapy resistance. Schematic depicting that HMGA1 maintains intracellular redox homeostasis against ferroptosis by assisting ATF4 to activate SLC7A11 transcription, resulting in ESCC resistance to chemotherapy.

Akkermansia muciniphila protects the intestine from irradiation-induced injury by secretion of propionic acid.

Intestinal dysbiosis frequently occurs in abdominal radiotherapy and contributes to irradiation (IR)-induced intestinal damage and inflammation. Akkermansia muciniphila (A. muciniphila) is a recently characterized probiotic, which is critical for maintaining the dynamics of the intestinal mucus layer and preserving intestinal microbiota homeostasis. However, the role of A. muciniphila in the alleviation of radiation enteritis remains unknown. In this study, we reported that the abundance of A. muciniphila was markedly reduced in the intestines of mice exposed to abdominal IR and in the feces of patients who received abdominal radiotherapy. Abundance of A. muciniphila in feces of radiotherapy patients was negatively correlated with the duration of diarrhea in patients. Administration of A. muciniphila substantially mitigated IR-induced intestinal damage and prevented mouse death. Analyzing the metabolic products of A. muciniphila revealed that propionic acid, a short-chain fatty acid secreted by the microbe, mediated the radioprotective effect. We further demonstrated that propionic acid bound to G-protein coupled receptor 43 (GRP43) on the surface of intestinal epithelia and increased histone acetylation and hence enhanced the expression of tight junction proteins occludin and ZO-1 and elevated the level of mucins, leading to enhanced integrity of intestinal epithelial barrier and reduced radiation-induced intestinal damage. Metformin, a first-line agent for the treatment of type II diabetes, promoted intestinal epithelial barrier integrity and reduced radiation intestinal damage through increasing the abundance of A. muciniphila. Together, our results demonstrated that A. muciniphila plays a critical role in the reduction of abdominal IR-induced intestinal damage. Application of probiotics or their regulators, such as metformin, could be an effective treatment for the protection of radiation exposure-damaged intestine.

Myofascial acupuncture versus routine acupuncture for mechanical neck pain: a protocol for a multicentre randomised controlled trial.

INTRODUCTION: Mechanical neck pain (MNP) is defined as pain in the area of the neck and/or neck-shoulder provoked by body mechanics and which adversely affects physical, psychological and social function. The treatments for MNP are limited. Previous studies and clinical experience have indicated that myofascial acupuncture might be a better treatment option for MNP, but the efficacy is controversial. Therefore, our aim is to compare the efficacy of myofascial acupuncture and routine acupuncture for MNP. METHODS AND ANALYSIS: The study is a multicentre, prospective randomised clinical trial. Patients will be recruited from four tertiary hospitals in China. A total of 438 participants with MNP will be randomly assigned into two groups, namely the 'Sancai-Tianbu' myofascial acupuncture group and the routine acupuncture group, at a ratio of 1:1. Each group will receive the acupuncture treatment twice a week for 21 days, totalling six sessions. The primary outcome will be the Visual Analogue Scale score. The secondary outcomes will be the Neck Disability Index, the cervical range of motion and the MOS 36-Item Short Form Health Survey. The assessments will be performed at baseline (immediately after allocation), pretreatment (5 min before every treatment), post-treatment (within 10 min after every treatment), postcourse (within 1 day after the course), and at 1, 3 and 6 months after the course. All patients will be included in the intent-to-treat analysis. Repeated-measure analysis of covariance will be used to determine the effects of the intervention on the outcome measures. ETHICS AND DISSEMINATION: Ethics approval was obtained from China Aerospace Science & Industry Corporation 731 Hospital, with permission number 2022-0204-01. Written informed consent will be obtained from the enrolled patients. Trial results will be disseminated in peer-reviewed publications. TRIAL REGISTRATION NUMBER: ChiCTR2200061453.

Effect of electroacupuncture on cyclic adenosine monophosphate-protein kinase A-vanillic acid receptor subtype 1 of the transient receptor potential/PLK-protein kinase C-vanillic acid receptor subtype 1 of the transient receptor potential pathway based on RNA-seq analysis in prostate tissue in rats with chronic prostatitis/chronic pelvic pain syndrome.

Objective: To investigate the analgesic mechanism of electroacupuncture (EA) in rats with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS). Methods: Thirty male SD rats were randomly divided into sham group, model group and EA group, with ten rats in each group. The CP/CPPS model was prepared by injecting 50 µL of complete Freund's adjuvant (CFA) into the ventral lobes of the prostate tissue, and the sham group was injected with the same dose of saline. After 14 days of modeling, EA was applied to Guanyuan (CV4), Zhongji (CV3), Sanyinjiao (SP6) and Huiyang (BL35) in the EA group. After four courses, H&E staining was performed to observe the prostate tissue morphology, transcriptome sequencing (RNA-Seq) was performed for each group, and the selected signaling pathways were verified by qRT-PCR. Results: The RNA-Seq analysis results suggested that the analgesic effect of EA on CP/CPPS may be achieved by regulating prostate gene expression, which may be related to multiple biological processes and signaling pathways. qRT-PCR results showed that the vanillic acid receptor subtype 1 of the transient receptor potential (TRPV1), phospholipase C (PLC), protein kinase C (PKC), cyclic adenosine monophosphate (cAMP), and protein kinase A (PKA) were all upregulated in the model group compared to the sham group (p < 0.01). Compared with the model group, TRPV1, PLC, PKC, cAMP, and PKA were all downregulated in the EA group (p < 0.05, p < 0.01). Conclusion: The analgesic mechanism of EA on CP/CPPS may be achieved through modulation of cAMP-PKA-TRPV1/PLC-PKC-TRPV1 signaling pathway.

Expression Profiling of L5-S2 Spinal Cord Dorsal Horn in a Rat Model of Chronic Pelvic Pain Syndrome Uncovers Potential Mechanism of Electroacupuncture Mediated Inflammation and Pain Responses.

Purpose: We aim to explore expression profiles of genes in SCDH of CPPS model rat relevant to pain and inflammation by RNA-Seq and to investigate the mechanism of anti-inflammatory and analgesic of EA. Methods: Thirty-six SD male rats were randomly divided into three groups (n = 12): sham operation, model, and EA. The rat CPPS model was established by injecting CFA into the ventral lobes of the prostate. The rats in EA group were treated at Guanyuan (CV4), Zhongji (CV3), Sanyinjiao (SP6) and Huiyang (BL35) for a total of 20 times, with a frequency of 2/100Hz. Mechanical allodynia, H&E staining and ELISA were used to detect the changes of pain threshold and tissue inflammation; RNA-Seq technique was used for profiling gene changes in SCDH and qRT-PCR was used for further validation. Results: Persistent mechanical allodynia and severe tissue inflammatory reaction both occurred in CPPS rats. After EA therapy, the pain sensitivity and inflammatory response of CPPS rats decreased significantly. RNA-Seq identified that a total of 46 DEGs were significantly up-regulated and 65 DEGs down-regulated after EA. GO enrichment showed that EA was mainly reflected in the regulation of the immune system by participating in the regulation of leukocyte, neutrophil cellular processes and cytokine metabolism. KEGG enrichment demonstrated that signal transduction and immune system were the most significant pathways. We further identified that the expressions of Pik3r2, Akt1, and Casp9 were significantly up-regulated and Jak2 and Stat3 down-regulated in the PI3K-AKT/JAK-STAT signal pathway. Conclusion: Our study revealed that immune and inflammatory responses are the main biological events that induce chronic pelvic pain in rats, and EA can exert anti-inflammatory and analgesic effects by regulating the expression of related genes on PI3K-AKT/JAK-STAT signal pathway in SCDH. This study provided putative novel targets of EA, which may have anti-inflammatory and analgesic effects of CPPS.

[Application of teaching method for the interpretation of acupoint names in the course of Science of Meridians and Acupoints].

The paper summarizes the valuable experience of the famous teachers of all generations in the teaching & research room of meridians and acupoints of Beijing University of CM. The shortcomings are presented when the acupoints are explained in accordance with the flowing route of meridians in classroom teaching of Science of Meridians and Acupoints. Hence, it is proposed that the acupoint names should be interpreted specially for the acupoints distributed on the same meridians or adjacent ones. It is suggested to emphasize the correlation of each acupoint with its adjacent ones from the perspective of the cultural connotation of acupoint names, and then, the differences and similarities in their clinical indications can be analyzed. Eventually, a new approach to the classroom teaching of Science of Meridians and Acupoints may be provided to guide the excavation of traditional cultural connotation and establish the cultural self-confidence and professional identity.

[Effect of electroacupuncture on pain threshold and expression of pain-related factors cyclooxygenase-2, prostaglandin E2 and ß-endorphin in rats with chronic pelvic pain syndrome].

OBJECTIVE: To explore the possible mechanism of electroacupuncture (EA) underlying improvement of chronic pelvic pain syndrome (CPPS). METHODS: Fifty SD rats were randomly divided into control, model, sham operation, EA and sham EA groups (n=10 rats in each group). The CPPS model was established by injecting complete Freund's adjuvant (CFA, 50 µL) into the ventral lobes of the prostate. EA (2 Hz/100 Hz) was applied to "Guanyuan"(CV4), "Zhongji"(CV3), "Sanyinjiao" (SP6) and "Huiyang"(BL35) once daily for 40 min, 5 days a week for 4 weeks, while rats in the sham EA group were treated with the same acupoints but without electrical stimulation. Mechanical pain threshold (MPT) and heat pain threshold (HPT) were measured before and after intervention. The body weight and prostate weight were measured and prostate index was calculated. Histopathological changes of prostate tissue were observed by HE staining. The levels of cycloxygenase-2 (COX-2), prostaglandin E2 (PGE2) and ß-endorphin (ß-EP) in prostate tissue were detected by ELISA. RESULTS: Compared with the control and sham operation groups, the MPT and HPT were significantly lower (P<0.01), and the prostate weight, prostate index, the contents of PGE2 and COX-2 were significantly increased (P<0.01), while the content of ß-EP was significantly decreased (P<0.01) in the model group. Compared with the model group, the MPT and HPT were significantly increased (P<0.01) after 3 and 4 courses of treatment, and the prostate weight, prostate index, the contents of PGE2 and COX-2 were significantly decreased (P<0.01), while the content of ß-EP was significantly increased (P<0.01) in the EA group, rather than in the sham EA group (P>0.05). CONCLUSION: EA can effectively relieve pain in CPPS rats, which may be related to its functions in down-regulating COX-2 and PGE2, and up-regulating ß-EP.

[Analysis of CiteSpace knowledge map for traditional Chinese medicine prevention and treatment of cerebral small vessel diseases].

This study aims to analyze the research on the prevention and treatment of cerebral small vessel diseases(CSVDs) with traditional Chinese medicine(TCM) based on knowledge map, and to preliminarily explore the research hotspots and trends. To be specific, articles on TCM treatment of CSVDs in CNKI, Wanfang, and VIP(from establishment to November 2021) were retrieved, followed by bibliometric analysis. Then CiteSpace 5.7 R4 and Gephi were employed for generation of maps on annual number of articles, author cooperation, institution cooperation, keyword co-occurrence, keyword clustering, and keyword emergence. A total of 106 eligible articles were screened out, and the annual number of articles presented a steady upward trend. A total of 277 authors were included in the author cooperation network, among whom CHEN Zhigang published the most articles. A total of 87 institutions were included in the institution cooperation network, among which Dongfang Hospital of Beijing University of Chinese Medicine showed the most frequent cooperation with other institutions. Keyword clustering showed that research on the TCM treatment of CSVDs mainly focused on five aspects: related disease research, neurological function deficits, disease nature and location in TCM, TCM treatment methods, and formulas. The prevention and treatment of CSVDs with TCM in China has been developing steadily in the past ten years, and TCM has unique advantages in the prevention and treatment of this disease. The knowledge maps vividly demonstrated the development and research hotspots and trends in this field. The result is expected to provide a reference for further research in this field.

Psychological crisis intervention for college students during novel coronavirus infection epidemic.

At the beginning of the 2020 New year, novel coronavirus infection continues to affect our lives. The anxiety and stress caused by rising epidemic data, the helplessness and fear caused by city closure and isolation, and the boredom and irritability caused by extended holiday grounding all have a great impact on the psychology of students. In this special stress period of "suspension of classes and non-stop learning", teachers actively help and guide students, do a good job of students' psychological support, perform the duties of spiritual mentors, and do a good job of students' psychological care.

Enhanced O-linked Glcnacylation in Crohn's disease promotes intestinal inflammation.

BACKGROUND: Treatment of Crohn's disease (CD) remains to be a challenge due to limited insights for its pathogenesis. We aimed to determine the role of O-Linked ß-N-acetylglucosamine (O-GlcNAc) in the development of CD and evaluate therapeutic effects of O-GlcNAc inhibitors on CD. METHODS: O-GlcNAc in intestinal epithelial tissues of CD, adherent-invasive Escherichia coli (AIEC) LF82-infected cells and mice was determined by immunoblot and immunohistochemistry. AIEC LF82 and dextran sulfate sodium were administrated into C57BL/6 mice for estabolishing inflammatory bowel disease model and for therapeutic study. FINDINGS: O-GlcNAc was increased in intestinal epithelial tissues of CD patients and AIEC LF82-infected mice. Infection of AIEC LF82 up-regulated the level of UDP-GlcNAc and increased O-GlcNAc in human colon epithelial HCT116 and HT-29 cells. We identified that IKKß and NF-κB were O-Glycosylated in AIEC LF82-treated cells. Mutations of IKKß (S733A) and p65 (T352A) abrogated the O-GlcNAc in IKKß and NF-κB and inhibited AIEC LF82-induced activation of NF-κB. Application of 6-diazO-5-oxO-L-norleucine, an agent that blocks the production of UDP-GlcNAc and inhibits O-GlcNAc, inactivated NF-κB in AIEC LF82-infected cells, enhanced the formation of autophagy, promoted the removal of cell-associated AIEC LF82, alleviated intestinal epithelial inflammation, and improved the survival of the colitis mice. INTERPRETATION: Intestinal inflammation in CD is associated with increased O-GlcNAc modification, which is required for NF-κB activation and suppression of autophagy. Targeting O-GlcNAc could be an effective therapy for inflammatory bowel disease. FUNDING: National Natural Science Foundation of China (Nos. 81573087 and 81772924) and International Cooperation Foundation of Jilin Province (20190701006GH).

[Acupoint selection rules in treating gastroesophageal reflux disease with acupuncture in China based on data mining].

OBJECTIVE: To analyze the rules of acupoint selection in the treatment of gastroesophageal reflux disease in China using data mining technology. METHODS: The published literature of treating gastroesophageal reflux disease with acupuncture was retrieved from electronic databases from January 1, 1983 to December 1, 2019, including SinoMed, CNKI, Wanfang and VIP database. Acupuncture prescription database was established, and the rules of acupoint selection were explored by statistical software SPSS 20.0 and SPSS Modeler 18.0. RESULTS: A total of 92 articles were included into this analysis, involving 92 acupuncture prescriptions, 76 acupoints. The total frequency of using these acupoints reached 549 times. Zhongwan (CV 12) was the most frequently used acupoint; the often selected meridians were conception vessel, stomach meridian, governor vessel, bladder meridian; the acupoints located at the abdomen, lower limbs and back were commonly selected; crossing points in the specific acupoints were commonly selected; the most frequently used group was Zusanli (ST 36)-Zhongwan (CV 12) and Neiguan (PC 6). CONCLUSION: Treating gastroesophageal reflux disease by acupuncture in China is dominated by shu-mu point combination, supplemented by mu-he point combination; yin meridians are emphasized as much as yang meridians; using specific acupoints is advocated, especially the crossing points.

[Effects of stand density on understory species diversity and soil physicochemical properties of Pinus massoniana plantation]. / æž—åˆ†å¯†åº¦å¯¹é©¬å°¾æ¾æž—æž—ä¸‹ç‰©ç§å¤šæ ·æ€§å’ŒåœŸå£¤ç†åŒ–æ€§è´¨çš„å½±å“.

We analyzed understory species diversity, soil physicochemical traits and their relationships in the 25-year-old non-commercial Pinus massoniana plantations with five different stand densities, i.e., 1057, 1136, 1231, 1383 and 1515 trees·hm-2, in Wenfeng Mountain, Xinjin District, Sichuan Province, China. The results showed that a total of 110 species were found, belonging to 57 families and 98 genera. With the increase of tree density, the understory species showed a succession pattern from positive to moderate to shady. Different densities had significant effects on the contents of total potassium and organic matter in the soils. With the increase ofdensity, the contents of organic matter and total potassium in understory vegetation first increased and then decreased. The trends of the relationship between both diversity and soil physiochemical characteristics and tree density were similar. Both of them increased with the increase of density, with the maximum value presented at the density of 1136 trees·hm-2. The concentrations of total phosphorus, available potassium, total potassium and total nitrogen was closely related to plant diversity index. The results suggested that the density at 1136 trees·hm-2 would be more beneficial to improve the stability of species diversity and soil fertility of P. massoniana non-commercial plantations in Wenfeng Mountain.

PARP-1 inhibitors sensitize HNSCC cells to APR-246 by inactivation of thioredoxin reductase 1 (TrxR1) and promotion of ROS accumulation.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Mutations of TP53 may reach 70% - 85% in HNSCC patients without human papillomavirus (HPV) infection. Recurrence rate remains particularly high for HNSCC patients with mutations in the TP53 gene although patients are responsive to surgery, irradiation, and chemotherapy early in the treatment. p53-Reactivation and Induction of Massive Apoptosis-1 (PRIMA-1) and its methylated analogue PRIMA-1Met (also known as APR-246) are quinuclidine compounds that rescue the DNA-binding activity of mutant p53 (mut-p53) and restore the potential of wild-type p53. In the current report, we demonstrated that inhibition of poly (ADP-ribose) polymerase-1 (PARP-1) with 6(5H)-phenanthridinone (PHEN) and N-(6-Oxo-5,6-dihydrophenanthridin-2-yl)-(N, N-dimethylamino) acetamide hydrochloride (PJ34) sensitizes UMSCC1, UMSCC14, and UMSCC17A, three HNSCC cell lines to the treatment of APR-246. PHEN enhances APR-246-induced apoptosis, but not programmed necrosis or autophagic cell death in HNSCC cells. The PARP-1 inhibition-induced sensitization of HNSCC cells to APR-246 is independent of TP53 mutation. Instead, PARP-1 inhibition promotes APR-246-facilitated inactivation of thioredoxin reductase 1 (TrxR1), leading to ROS accumulation and DNA damage. Overexpression of TrxR1 or application of antioxidant N-acetyl-L-cysteine (NAC) depletes the ROS increase, reduces DNA damage, and decreases cell death triggered by APR-246/PHEN in HNSCC cells. Thus, we have characterized a new function of PARP-1 inhibitor in HNSCC cells by inactivation of TrxR1 and elevation of ROS and provide a novel therapeutic strategy for HNSCC by the combination of PARP-1 inhibitors and APR-246.

Piperlongumine and p53-reactivator APR-246 selectively induce cell death in HNSCC by targeting GSTP1.

TP53 mutations frequently occur in head and neck squamous cell carcinoma (HNSCC) patients without human papillomavirus infection. The recurrence rate for these patients is distinctly high. It has been actively explored to identify agents that target TP53 mutations and restore wild-type (WT) TP53 activities in HNSCC. PRIMA-1 (p53-reactivation and induction of massive apoptosis-1) and its methylated analogue PRIMA-1Met (also called APR-246) were found to be able to reestablish the DNA-binding activity of p53 mutants and reinstate the functions of WT p53. Herein we report that piperlongumine (PL), an alkaloid isolated from Piper longum L., synergizes with APR-246 to selectively induce apoptosis and autophagic cell death in HNSCC cells, whereas primary and immortalized mouse embryonic fibroblasts and spontaneously immortalized non-tumorigenic human skin keratinocytes (HaCat) are spared from the damage by the co-treatment. Interestingly, PL-sensitized HNSCC cells to APR-246 are TP53 mutation-independent. Instead, we demonstrated that glutathione S-transferase pi 1 (GSTP1), a GST family member that catalyzes the conjugation of GSH with electrophilic compounds to fulfill its detoxification function, is highly expressed in HNSCC tissues. Administration of PL and APR-246 significantly suppresses GSTP1 activity, resulting in the accumulation of ROS, depletion of GSH, elevation of GSSG, and DNA damage. Ectopic expression of GSTP1 or pre-treatment with antioxidant N-acetyl-L-cysteine (NAC) abrogates the ROS elevation and decreases DNA damage, apoptosis, and autophagic cell death prompted by PL/APR-246. In addition, administration of PL and APR-246 impedes UMSCC10A xenograft tumor growth in SCID mice. Taken together, our data suggest that HNSCC cells are selectively sensitive to the combination of PL and APR-246 due to a remarkably synergistic effect of the co-treatment in the induction of ROS by suppression of GSTP1.