Cancer cell-autonomous cGAS-STING response confers drug resistance.

The cGAS-STING pathway has long been recognized as playing a crucial role in immune surveillance and tumor suppression. Here, we show that when the pathway is activated in a cancer-cell-autonomous response manner, it confers drug resistance. Targeted or conventional chemotherapy drugs promoted cytosolic DNA accumulation in cancer cells, activating the cGAS-STING pathway and downstream TBK1-IRF3/NF-κB signaling. This cancer cell-intrinsic response enabled the cells to counteract drug stress, allowing treatment resistance to be acquired and maintained. Blockade of stimulator of interferon genes (STING) signaling delayed and overcame resistance in models in vitro and in vivo. This finding uncovers an alternative face of cGAS-STING signaling other than the well-reported modulation of microenvironmental immune cells. It also implies a caution for the combination of STING agonist with targeted or conventional chemotherapy drug treatment, a strategy prevailing in current clinical trials.

Erratum: Aldehyde dehydrogenase 1A1 confers erlotinib resistance via facilitating the reactive oxygen species-reactive carbonyl species metabolic pathway in lung adenocarcinomas: Erratum.

[This corrects the article DOI: 10.7150/thno.35729.].

A phosphoglycerate mutase 1 allosteric inhibitor overcomes drug resistance to EGFR-targeted therapy via disrupting IL-6/JAK2/STAT3 signaling pathway in lung adenocarcinoma.

Resistance to epidermal growth factor receptor (EGFR) inhibitors, from the first-generation erlotinib to the third generation osimertinib, is a clinical challenge in the treatment of patients with EGFR-mutant lung adenocarcinoma. Our previous work found that a novel allosteric inhibitor of phosphoglycerate mutase 1 (PGAM1), HKB99, restrains erlotinib resistance in lung adenocarcinoma cells. However, the role of HKB99 in osimertinib resistance and its underlying molecular mechanism remains to be elucidated. Herein, we found that IL-6/JAK2/STAT3 signaling pathway is aberrantly activated in both erlotinib and osimertinib resistant cells. Importantly, HKB99 significantly blocks the interaction of PGAM1 with JAK2 and STAT3 via the allosteric sites of PGAM1, which leads to inactivation of JAK2/STAT3 and thereby disrupts IL-6/JAK2/STAT3 signaling pathway. Consequently, HKB99 remarkably restores EGFR inhibitor sensitivity and exerts synergistic tumoricidal effect. Additionally, HKB99 alone or in combination with osimertinib down-regulated the level of p-STAT3 in xenograft tumor models. Collectively, this study identifies PGAM1 as a key regulator in IL-6/JAK2/STAT3 axis in the development of resistance to EGFR inhibitors, which could serve as a therapeutic target in lung adenocarcinoma with acquired resistance to EGFR inhibitors.

Targeting AKR1B1 inhibits glutathione de novo synthesis to overcome acquired resistance to EGFR-targeted therapy in lung cancer.

Acquired resistance represents a bottleneck to molecularly targeted therapies such as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment in lung cancer. A deeper understanding of resistance mechanisms can provide insights into this phenomenon and help to develop additional therapeutic strategies to overcome or delay resistance. Here, we identified a pharmacologically targetable metabolic mechanism that drives resistance to EGFR TKIs in lung cancer cell lines and patient-derived xenograft mice. We demonstrated that aldo-keto reductase family 1 member B1 (AKR1B1) interacts with and activates signal transducer and activator of transcription 3 (STAT3) to up-regulate the cystine transporter solute carrier family 7 member 11 (SLC7A11). This leads to enhanced cystine uptake and flux to glutathione de novo synthesis, reactive oxygen species (ROS) scavenging, protection from cell death, and EGFR TKI drug resistance in lung cancer cell lines and xenograft mouse models. Suppression of AKR1B1 with selective inhibitors, including the clinically approved antidiabetic drug epalrestat, restored the sensitivity of resistant cell lines to EGFR TKIs and delayed resistance in lung cancer patient-derived xenograft mice. Our findings suggest a metabolic mechanism for resistance to a molecularly targeted therapy and provide a potential therapeutic target for overcoming resistance to EGFR TKIs, including the third-generation inhibitor osimertinib.

NRF2-GPX4/SOD2 axis imparts resistance to EGFR-tyrosine kinase inhibitors in non-small-cell lung cancer cells.

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have achieved satisfactory clinical effects in the therapy of non-small cell lung cancer (NSCLC), but acquired resistance limits their clinical application. NRF2 has been shown to enhance the resistance to apoptosis induced by radiotherapy and some chemotherapy. In this study, we investigated the role of NRF2 in resistance to EGFR-TKIs. We showed that NRF2 protein levels were markedly increased in a panel of EGFR-TKI-resistant NSCLC cell lines due to slow degradation of NRF2 protein. NRF2 knockdown overcame the resistance to EGFR-TKIs in HCC827ER and HCC827GR cells. Furthermore, we demonstrated that NRF2 imparted EGFR-TKIs resistance in HCC827 cells via upregulation of GPX4 and SOD2, and suppression of GPX4 and SOD2 reversed resistance to EGFR-TKIs. Thus, we conclude that targeting NRF2-GPX4/SOD2 pathway is a potential strategy for overcoming resistance to EGFR-TKIs.

Development and validation of a rapid, robust and sensitive UPLC-QQQ-MS/MS method for simultaneous quantification of GSH metabolism in lung cancer cells.

Changes in cellular metabolism accompany tumor therapeutic resistance. Metabolite concentrations specifically reflect the cellular state. Glutathione (GSH) metabolism maintains the redox homeostasis while also confers therapeutic resistance to cancer cells. However, analytical methods for studying GSH metabolism rely on high-resolution-based untargeted metabolomics. Since the aim of untargeted metabolomics studies is covering as much metabolites as possible, these methods lack sensitivity for simultaneous analysis of intracellular GSH-related metabolites with different polarities and structures. In this study, based on cultured lung cancer cells, we described a rapid, robust and sensitive ultra-performance liquid chromatography-triple quadrupole tandem mass spectrographic method (UPLC-QQQ-MS/MS) to simultaneously quantify a repertoire of GSH-related metabolites, including GSH, GSSG, glycine, cysteine, glutamine, glutamate, cystine, γ-glutamyl-cysteine and cysteinyl-glycine. This method avoided the use of derivatization and/or ion-pairing reagents and was validated according to United States Food and Drug Administration (US FDA) criteria. The lower limit of quantification was determined to be 0.5-100 ng/mL with lower limits of detection at 0.14-10.07 ng/mL. The intra- and inter-day precision values for all the analytes were <15% CV, and the accuracy ranged from 85.4% to 114% at three levels of quality control. This method combined simple preparation with rapid analytical procedure (8 min), allowed for high-throughput analysis of GSH metabolism in basic and therapeutic treatment conditions within cultured cells. Our data showed a significant alteration of GSH metabolism in two independent resistant cells compared to sensitive cells. This method monitored the impact of molecularly targeted drugs on GSH metabolism within lung cancer cells and therefore helped identifying potential metabolic vulnerability for the therapeutic resistance in lung cancer.

Aldehyde dehydrogenase 1A1 confers erlotinib resistance via facilitating the reactive oxygen species-reactive carbonyl species metabolic pathway in lung adenocarcinomas.

Background: Acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) such as erlotinib is a major challenge to achieve an overall clinical benefit of the targeted therapy. Recently, aldehyde dehydrogenase 1 (ALDH1) induction has been found to render lung adenocarcinomas resistant to EGFR-TKIs, and targeting ALDH1A1 becomes a novel strategy to overcome resistance. However, the molecular mechanism underlying such effect remains poorly understood. Methods: Comprehensive assays were performed in a panel of lung adenocarcinoma cell lines and xenografts that acquired resistance to erlotinib. Cancer phenotype was evaluated by cell viability, apoptosis, migration, and epithelial-mesenchymal transition analysis in vitro, tumorsphere formation analysis ex vivo, and tumor growth and dissemination analysis in vivo. Reactive oxygen species (ROS) and reactive carbonyl species (RCS) were detected based on fluorescent oxidation indicator and liquid chromatography coupled to mass spectrometry, respectively. Protein target was suppressed by RNA interference and pharmacological inhibition or ecto-overexpressed by lentivirus-based cloning. Gene promoter activity was measured by dual-luciferase reporting assay. Results: Knockdown or pharmacological inhibition of ALDH1A1 overcame erlotinib resistance in vitro and in vivo. ALDH1A1 overexpression was sufficient to induce erlotinib resistance. Metabolomic analysis demonstrated lower ROS-RCS levels in ALDH1A1-addicted, erlotinib-resistant cells; in line with this, key enzymes for metabolizing ROS and RCS, SOD2 and GPX4, respectively, were upregulated in these cells. Knockdown of SOD2 or GPX4 re-sensitized the resistant cells to erlotinib and the effect was abrogated by ROS-RCS scavenging and mimicked by ROS-RCS induction. The ALDH1A1 overexpressed cells, though resisted erlotinib, were more sensitive to SOD2 or GPX4 knockdown. The ALDH1A1 effect on erlotinib resistance was abrogated by ROS-RCS induction and mimicked by ROS-RCS scavenging. Detection of GPX4 and SOD2 expression and analysis of promoter activities of GPX4 and SOD2 under the condition of suppression or overexpression of ALDH1A1 demonstrated that the RCS-ROS-metabolic pathway was controlled by the ALDH1A1-GPX4-SOD2 axis. The ROS-RCS metabolic dependence mechanism in ALDH1A1-induced resistance was confirmed in vivo. Analysis of public databases showed that in patients undergoing chemotherapy, those with high co-expression of ALDH1A1, GPX4, and SOD2 had a lower probability of survival. Conclusions: ALDH1A1 confers erlotinib resistance by facilitating the ROS-RCS metabolic pathway. ALDH1A1-induced upregulation of SOD2 and GPX4, as well as ALDH1A1 itself, mitigated erlotinib-induced oxidative and carbonyl stress, and imparted the TKI resistance. The elucidation of previously unrecognized metabolic mechanism underlying erlotinib resistance provides new insight into the biology of molecular targeted therapies and help to design improved pharmacological strategies to overcome the drug resistance.

Purification and characterization of a novel ubiquitin-like antitumour protein with hemagglutinating and deoxyribonuclease activities from the edible mushroom Ramaria botrytis.

A novel ubiquitin-like antitumour protein (RBUP) was isolated from fruiting bodies of the edible mushroom Ramaria botrytis. The protein was isolated with a purification protocol involving ion exchange chromatography on DEAE-Sepharose fast flow and gel filtration on Sephadex G-75. SDS-PAGE, Native-PAGE and ultracentrifugation analysis disclosed that RBUP was a monomeric protein with a molecular weight of 18.5 kDa. ESI-MS/MS demonstrated that it shared 69% amino acid sequence similarity with Coprinellus congregates ubiquitin (gi|136667). The protein exhibiting strong anticancer activity towards A549 cells. Analysis by employing AO/EB staining and Annexin V-FITC/PI detection indicated that the cytotoxic effect of RBUP was mediated through induction of apoptosis. Furthermore, RBUP displayed hemagglutinating and deoxyribonuclease activities. A temperature of 40 °C and pH of 7.0 were required for optimal DNase activity. Therefore, it was estimated that RBUP exerted its antitumour effect by inducing apoptosis, and its hemagglutinating and DNase activities were also thought to participate in this effect. These results demonstrated that RBUP was a multifunctional protein with potential medicinal applications.

Multidisciplinary effort in treating children with hepatoblastoma in China.

The purpose of this study is to report the first nationwide protocol (Wuhan Protocol) developed by Chinese Children's Cancer Group and the results of multidisciplinary effort in treating hepatoblastoma. In this study, we reported the final analysis, which includes 153 hepatoblastoma patients in 13 hospitals from January 2006 to December 2013. The 6-year overall survival and event-free survival rates were 83.3 ± 3.1% and 71.0 ± 3.7%, respectively, in this cohort. The univariate analysis revealed that female (P = 0.027), under 5 years of age (P = 0.039), complete surgical resection (P = 0.000), no metastases (P = 0.000), and delayed surgery following neoadjuvant chemotherapy (P = 0.000) had better prognosis. In multivariate analysis, male, 5 years of age or above, stage PRETEXT III or IV, and incomplete surgical resection were among the some adverse factors contributing to poor prognosis. The preliminary results from this study showed that patients who underwent treatment following Wuhan Protocol had similar OS and EFS rates compared to those in developed countries. However, the protocol remains to be further optimized in standardizing surgical resection (including liver transplantation), refining risk stratification and risk-based chemotherapy.

Engineered measles virus Edmonston strain used as a novel oncolytic viral system against human neuroblastoma through a CD46 and nectin 4-independent pathway.

Neuroblastoma (NB) is the most common extracranial solid tumor in children. In this study, we investigated the potential antitumor capability of the engineered Edmonston strain of the carcinoembryonic antigen-expressing measles virus (MV-CEA) against human NB. The infection of a variety of NB cell lines, including SK-N-SH, SMS-KCNR, and primary NB cells, resulted in significant cytopathic effects. None of the NB cell lines showed an overexpression of the measles virus receptor CD46 and nectin 4, but the cell lines did support robust viral replication. The efficacy of this approach was examined in murine SK-N-SH xenograft models. Flow cytometry and TUNEL assays indicated an apoptotic mechanism of cell death. In summary, MV-CEA has potent therapeutic efficacy against NB mediated by a CD46- and nectin 4-independent pathway.

Alveolar soft part sarcoma occurring on the abdominal wall of a 2-year-old child.

Alveolar soft part sarcoma (ASPS) is a rare soft tissue malignant neoplasm that affects young people. It can occur in any region of the body and at any stage of development. But ASPS on the abdominal wall is rarely reported. However, a few cases were reported in children under the age of 10 years. In this study we report a case of ASPS that occurred on the abdominal wall of a 2-year-old patient.

Thoracoabdominal foregut duplication cyst with respiratory epithelium and alimentary epithelium.

Thoracoabdominal foregut duplication is a rare congenital abnormality. The authors report a case of thoracoabdominal foregut duplication cyst in a 13-year-old male patient. The pathologic report revealed that a thoracic mass with a pseudostratified, ciliated, columnar epithelial lining (respiratory tract epithelium), an abdominal mass with gastric mucosa (alimentary tract epithelium), and the cyst originated from the foregut.

Ileal duplication with extensive gastric heterotopia in a girl.

BACKGROUND: Gastrointestinal duplications are rare congenital abnormalities known to occur at any level of the alimentary tract from the mouth to the anus. The cause of intestinal duplication has not been established. Several theories have been put forward to explain different types of duplications. Some of these duplications are large sized and giant, and only 4 cases have been reported. METHODS: A 4-year-old girl was referred to our hospital with a history of abdominal pain, abdominal distension, and diarrhea mixed with black blood for 20 days. Technetium-99m scintigraphy identified heterotopic gastric mucosa at the middle and lower abdominal region. Enteric duplication was suspected. RESULTS: Operatively, duplication was found to be located at the ileum with abnormal hypertrophy in shape, 50 cm of the ileum was resected, and an ileoileal end-to-end anastomosis was made. Stomach-like mucosa and some ring structures were identified instead of the normal intestinal mucosa when opening this ileal duplication. Microscopically, most of mucosa showed gastric corpusfundic glands. CONCLUSIONS: This is an unusual case of enteric duplication. Ultrasonography, computed tomography and technetium-99m scintigraphy are helpful in the diagnosis of duplication.

Thoracic rib solitary eosinophilic granuloma in a child.

Eosinophilic granuloma is characterized by single or multiple skeletal lesions occurring predominantly in children, adolescents, and young adults, it accounts for 70% of Langerhans cell histiocytosis. The common sites are the skull, mandible, ribs, spines, and long bones particularly the femur and the humerus. Thoracic rib involvement is rarely seen. It was often regarded as malignant soft tissue tumor. We report an unusual case of eosinophilic granuloma in a female child presented with a solitary lesion at the thoracic rib.

Presacral extrarenal Wilms tumor in a child.

OBJECTIVES: Wilms tumor (WT) is one of the most common solid tumors in children. It also is the most frequent tumor found in the kidneys. In 5% of cases, it affects both kidneys simultaneously. Extrarenal WTs are extremely rare. The diagnosis of extrarenal WT is almost always made after surgical intervention. The tumor can be located in the retroperitoneum, uterus, cervix, testes, skin, and even the thorax. METHODS: We report on a 3-year-old girl with an extrarenal WT located in the presacral region. RESULTS: The exact mechanism whereby a WT occurs in extrarenal tissues is unknown. The presence of ectopic metanephric blastema cells or the WT gene causing transformation of extrarenal primitive mesonephric or pronephric remnants into WT have both been considered in the embryogenesis. Although imaging examinations are helpful in the definition of retroperitoneal tumors, no characteristic findings are available to diagnose an extrarenal WT before surgery. CONCLUSIONS: As a rule, the diagnosis of extrarenal WT is made after surgery. Surgical excision is the treatment of choice and the same general therapeutic rules should be followed as when the kidney has been affected. The use of Stage III guidelines for chemotherapy and radiotherapy are appropriate for these patients.

Clinical images. Primary non-Hodgkin's lymphoma of the sigmoid colon in a child.

Primary non-Hodgkin's lymphomas of the gastrointestinal tract are rare in children, and few of these lymphomas are located in the sigmoid colon. The preoperative diagnosis rate is low. Complete resection is indicated if it can be done safely. Combination chemotherapy after resection is indicated.

Mesenteric Castleman disease.

Castleman disease is a rare benign lymph node hyperplasia usually presenting as an asymptomatic mediastinal mass in children. It can present at any extrathoracic site where there is lymphoid tissue. The sites include retroperitoneum, mesentery, axilla, and pelvis. Mesenteric Castleman disease is very rare in children.