Refractory Tumors Research Articles

Liver X receptors agonist T0901317 exerts ferroptosis sensitization in cancer.

Numerous studies have confirmed the anticancer effects of ferroptosis on a wide range of tumors, specifically in providing new perspectives for tackling drug resistance and treating refractory tumors. Notably, mechanisms of improving tumor susceptibility to ferroptosis have been a focus of current research. This study discovered that co-treatment of LXRS agonist T0901317 and ferroptosis inducers (FINs) significantly inhibited the proliferation of cancer cells, this inhibition effect could be reversed by specific inhibitors of ferroptosis and accompanied by elevated lipid peroxides. Glutathione peroxidase 4 (GPX4) regulates T0901317 induced ferroptotic sensitization, and its overexpression dramatically reverses the joint anticancer effect of T0901317 and FINs. Furthermore, xenograft model results highly confirmed the ferroptotic sensitization effect of T0901317 in vivo. In summary, our findings indicate that drug combination and ferroptosis induction strategies provide novel options for cancer therapy.

Significant response to atezolizumab plus bevacizumab treatment in unresectable hepatocellular carcinoma with major portal vein tumor thrombus: a case report

BackgroundHepatocellular carcinoma (HCC) with major portal vein tumor thrombus (Vp4 PVTT) is an extremely advanced tumor with limited treatment options. Systemic chemotherapy is the only recommended treatment option, and atezolizumab plus bevacizumab has recently emerged as a first-line treatment option.Case presentationWe describe the case of an 82-year-old man with unresectable advanced HCC with Vp4 PVTT who achieved a significant response to atezolizumab plus bevacizumab treatment. A single administration of atezolizumab plus bevacizumab ensured significant anti-tumor effects (regression in the tumor size and PVTT, portal vein recanalization, and serum alfa-fetoprotein levels decreased from 90,770 to 89 ng/mL). The patient continued with atezolizumab monotherapy, and after nine consecutive regimens, there was no apparent sign of residual tumor.ConclusionsThis case demonstrates the powerful anti-tumor effect of atezolizumab plus bevacizumab treatment for advanced HCC with Vp4 PVTT, suggesting that these agents can be a promising treatment option for such refractory tumors.

Quaternary Ammonium Salts Anchored on Cross-Linked (R)-(+)-Lipoic Acid Nanoparticles for Drug-Resistant Tumor Therapy.

A membrane-lytic mechanism-based nanodrug is developed for drug-resistant tumor therapy by anchoring the small-molecule quaternary ammonium salt (QAS) on cross-linked (R)-(+)-lipoic acid nanoparticles (cLANs). The anchoring of QAS on the nanoparticle avoids the direct attack of long alkyl chains to the cell membrane under physiological conditions, while after entering tumor cells, the QAS is released from the dissociated cLANs, migrates to the phospholipid bilayer via electrostatic interaction, and destroys the cell membrane by the puncture of long alkyl chains. Since the QAS is designed to finally be hydrolyzed to amino acid betaine and food additive cetanol and the cLANs degrade to dihydrolipoic acid (DHLA, reduced form of dietary antioxidant lipoic acid in cells), the QAS@cLANs hold superior biosafety. In addition to the drug-resistant tumors, the QAS@cLANs demonstrate significant inhibition of metastatic tumors. This work provides not only a general and clinic-promising treatment for the refractory tumors but also opens a door for the medicinal use of QAS.

Methodological advances in the discovery of novel neuroblastoma therapeutics

ABSTRACT Introduction Neuroblastoma is a cancer of the sympathetic nervous system that causes up to 15% of cancer-related deaths among children. Among the ~1,000 newly diagnosed cases per year in Europe, more than half are classified as high-risk, with a 5-year survival rate <50%. Current multimodal treatments have improved survival among these patients, but relapsed and refractory tumors remain a major therapeutic challenge. A number of new methodologies are paving the way for the development of more effective and safer therapies to ultimately improve outcomes for high-risk patients. Areas covered The authors provide a critical review on methodological advances aimed at providing new therapeutic opportunities for neuroblastoma patients, including preclinical models of human disease, generation of omics data to discover new therapeutic targets, and artificial intelligence-based technologies to implement personalized treatments. Expert opinion While survival of childhood cancer has improved over the past decades, progress has been uneven. Still, survival is dismal for some cancers, including high-risk neuroblastoma. Embracing new technologies (e.g. molecular profiling of tumors, 3D in vitro models, etc.), international collaborative efforts and the incorporation of new therapies (e.g. RNA-based therapies, epigenetic therapies, immunotherapy) will ultimately lead to more effective and safer therapies for these subgroups of neuroblastoma patients.

Ikaros Mediates Antigen Escape Following CD19 CAR T Cell Therapy in r/r B-ALL

Despite impressive response to front-line treatment, relapsed or refractory B-cell acute lymphoblastic leukemia (r/r B-ALL) remains one of the most common causes of death in children with cancer. In pediatric and adult r/r B-ALL, CD19 CAR T cell (CART19) therapy has shown impressive results with over 80% of patients achieving complete remission. However, as an unintended consequence of long-term persistence of CAR T cells and the resulting sustained pressure against CD19 expressing cells, 30 - 70% of initial responders will eventually relapse with CD19 loss. Early identification of patients that will respond successfully to CART19 therapy vs. those at risk for CD19 Neg relapse would support clinical decision making and improve patient care.To address this problem, we profiled by mass cytometry (CyTOF) 25 pre-CART19 samples including patients that achieved a durable complete remission (CR, n = 6), patients that underwent CD19 Neg (n = 11) or CD19 Pos relapse (n = 4) and patients that were refractory to CART19 (n = 4). For 14 of those patients, we also analyzed paired post-CART19 samples: 8 from CD19 Neg relapse, 2 from CD19 Pos relapse, and 4 from refractory tumors. We observed a significant increase in the proportion of leukemic early progenitor non-B cells (called early-non-BI) after CD19 Neg relapse, suggesting that CD19 loss is associated with the loss of other B cell features. In addition, in the pre-CART19 samples we identified a subpopulation of CD19 Pos pro-B cells that resemble early-non-BI cells. We hypothesized that these pro-B “discordant” cells are able to lose CD19 expression and escape the immune pressure exerted by the CART19, leading to CD19 Neg relapse. Closer analysis revealed lower levels of IKAROS in pro-B discordant cells from patients that underwent CD19 Neg relapse, than in those that achieved a durable CR.To further explore the difference between pro-B discordant cells from patients that achieved a durable CR or underwent CD19 Neg relapse, we performed single cell REAP-seq (RNA expression and protein sequencing) from 3 pre-CART19 CR and 3 pre-CART19 CD19 Neg relapse r/r B-ALL samples. From this analysis, we confirmed a subpopulation of leukemic pro-B like cells with decreased expression of IKZF1 in those patients that underwent CD19 Neg relapse.IKAROS is a transcription factor that plays a crucial role in B cell lineage specification and commitment and is a known B-ALL tumor suppressor. Genetic alterations affecting the IKAROS gene, IKZF1, have been associated with poor response to front-line treatment and they are a factor in relapse risk stratification. However, a role for IKAROS in CART19 failure has not been described. To assess if there is a correlation between the levels of IKAROS and CD19 surface expression, we manipulated IKAROS levels in B-ALL cell lines through RNA silencing and targeted protein degradation approaches. Consistently, we observed that CD19 surface expression diminishes upon IKAROS downregulation. To determine how IKAROS regulates CD19 expression, we performed CyTOF, RNA-seq and ATAC-seq analysis of isogenic B-ALL cell lines with wild-type or reduced (IKAROS KD) IKAROS levels. While the chromatin accessibility to CD19 regulatory regions did not change, CD19 mRNA levels were lower in IKAROS KD cells. Interestingly, we found that IKAROS regulates several genes associated with mRNA splicing. In particular, CD19 mRNA preferentially retains intron 10 in IKAROS KD cells. The inclusion of intron 10 introduces several premature stop codons. Moreover, IKAROS KD B-ALL cells more closely resemble myeloid cells based on their gene expression profiles, suggesting a loss in their B cell identity.In summary, this is the first description of a leukemia-specific subpopulation of CD19 Pos pro-B discordant cells in patients prior CART19 administration. Furthermore, lower levels of IKAROS in this subpopulation correlates with poor response to CART19 therapy. Preliminary molecular analysis suggests that low IKAROS result in retention of CD19 intron 10 and loss of B-cell identity (Figure 1). Future research will focus on in-depth characterization of the myeloid-like phenotype induced by low levels of IKAROS expression, and the impact that intron 10 retention has on CD19 mRNA stability and surface expression. [Display omitted] DisclosuresMullighan: Pfizer: Research Funding; Amgen: Current equity holder in publicly-traded company; Illumina: Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding. Grupp: Novartis, Roche, GSK, Humanigen, CBMG, Eureka, and Janssen/JnJ: Consultancy; Novartis, Adaptimmune, TCR2, Cellectis, Juno, Vertex, Allogene and Cabaletta: Other: Study steering committees or scientific advisory boards; Novartis, Kite, Vertex, and Servier: Research Funding; Jazz Pharmaceuticals: Consultancy, Other: Steering committee, Research Funding. Barrett: Tmunity Therapeutics: Current Employment. Davis: Novartis Pharmaceuticals: Honoraria; Jazz Pharmaceuticals: Research Funding.

Enhancing Natural Killer Cell Targeting of Pediatric Sarcoma

Osteosarcoma, Ewing sarcoma (EWS), and rhabdomyosarcoma (RMS) are the most common pediatric sarcomas. Conventional therapy for these sarcomas comprises neoadjuvant and adjuvant chemotherapy, surgical resection of the primary tumor and/or radiation therapy. Patients with metastatic, relapsed, or refractory tumors have a dismal prognosis due to resistance to these conventional therapies. Therefore, innovative therapeutic interventions, such as immunotherapy, are urgently needed. Recently, cancer research has focused attention on natural killer (NK) cells due their innate ability to recognize and kill tumor cells. Osteosarcoma, EWS and RMS, are known to be sensitive to NK cell cytotoxicity in vitro. In the clinical setting however, NK cell cytotoxicity against sarcoma cells has been mainly studied in the context of allogeneic stem cell transplantation, where a rapid immune reconstitution of NK cells plays a key role in the control of the disease, known as graft-versus-tumor effect. In this review, we discuss the evidence for the current and future strategies to enhance the NK cell-versus-pediatric sarcoma effect, with a clinical focus. The different approaches encompass enhancing antibody-dependent NK cell cytotoxicity, counteracting the NK cell mechanisms of self-tolerance, and developing adoptive NK cell therapy including chimeric antigen receptor-expressing NK cells.

Analysis of NIS Plasma Membrane Interactors Discloses Key Regulation by a SRC/RAC1/PAK1/PIP5K/EZRIN Pathway with Potential Implications for Radioiodine Re-Sensitization Therapy in Thyroid Cancer.

Simple SummaryThe presence of the sodium–iodide symporter (NIS) at the plasma membrane (PM) of differentiated thyroid cancer (DTC) cells is required for the successful use of radioiodine (RAI) therapy in these malignancies. However, NIS is frequently downregulated in malignant thyroid tissue, and 30% to 50% of metastatic DTCs become refractory to RAI treatment. Notably, many RAI-refractory DTCs still show relatively abundant NIS protein levels despite failing to uptake sufficient iodide to enable RAI therapy. This suggests an impairment in the NIS delivery and retention at the PM. Because little is known about these mechanisms, we employed a new experimental strategy to purify and characterize proteins which are selectively associated with NIS at the PM. We found that, when at the PM, NIS is particularly associated with proteins that regulate the cell’s actin cytoskeleton. Further investigation revealed that several of these proteins integrate an intracellular signaling pathway that modulates the functional localization of NIS at the PM, in normal and DTC cells. Our findings open new venues for therapeutic intervention in refractory DTC, envisioning the re-sensitization of these tumors to RAI therapy.The functional expression of the sodium–iodide symporter (NIS) at the membrane of differentiated thyroid cancer (DTC) cells is the cornerstone for the use of radioiodine (RAI) therapy in these malignancies. However, NIS gene expression is frequently downregulated in malignant thyroid tissue, and 30% to 50% of metastatic DTCs become refractory to RAI treatment, which dramatically decreases patient survival. Several strategies have been attempted to increase the NIS mRNA levels in refractory DTC cells, so as to re-sensitize refractory tumors to RAI. However, there are many RAI-refractory DTCs in which the NIS mRNA and protein levels are relatively abundant but only reduced levels of iodide uptake are detected, suggesting a posttranslational failure in the delivery of NIS to the plasma membrane (PM), or an impaired residency at the PM. Because little is known about the molecules and pathways regulating NIS delivery to, and residency at, the PM of thyroid cells, we here employed an intact-cell labeling/immunoprecipitation methodology to selectively purify NIS-containing macromolecular complexes from the PM. Using mass spectrometry, we characterized and compared the composition of NIS PM complexes to that of NIS complexes isolated from whole cell (WC) lysates. Applying gene ontology analysis to the obtained MS data, we found that while both the PM-NIS and WC-NIS datasets had in common a considerable number of proteins involved in vesicle transport and protein trafficking, the NIS PM complexes were particularly enriched in proteins associated with the regulation of the actin cytoskeleton. Through a systematic validation of the detected interactions by co-immunoprecipitation and Western blot, followed by the biochemical and functional characterization of the contribution of each interactor to NIS PM residency and iodide uptake, we were able to identify a pathway by which the PM localization and function of NIS depends on its binding to SRC kinase, which leads to the recruitment and activation of the small GTPase RAC1. RAC1 signals through PAK1 and PIP5K to promote ARP2/3-mediated actin polymerization, and the recruitment and binding of the actin anchoring protein EZRIN to NIS, promoting its residency and function at the PM of normal and TC cells. Besides providing novel insights into the regulation of NIS localization and function at the PM of TC cells, our results open new venues for therapeutic intervention in TC, namely the possibility of modulating abnormal SRC signaling in refractory TC from a proliferative/invasive effect to the re-sensitization of these tumors to RAI therapy by inducing NIS retention at the PM.

Chemotherapy and targeted therapies for meningiomas: what is the evidence?

Although most meningiomas are slow growing tumors mainly controlled by surgery with or without radiotherapy, aggressive meningiomas that fail these conventional treatments constitute a rare situation, a therapeutic challenge and an unmet need in neuro-oncology. Mutational landscape in recurrent high-grade meningiomas includes mainly NF2 mutation or 22q chromosomal deletion, whereas telomerase reverse transcriptase promoter, BAP-1 and CDK2NA mutations were also found in aggressive meningiomas. Pi3K-Akt-mTOR pathway is currently the most relevant intracellular signaling pathway target in meningiomas with preliminary clinical activity observed. Assessment of drug activity with progression free survival rate at 6 months is challenging in regard to meningioma growth rate heterogeneity, so that 3-dimensional growth rate before and during treatment could be considered in the future to selected new active drugs. Despite a low evidence level, some systemic therapies may be considered for patients with recurrent meningioma not amenable to further surgery or radiotherapy. In recurrent high-grade meningioma, everolimus-octreotide combination, bevacizumab, sunitinib and peptide receptor radionuclide therapy exhibit a signal of activity that may justify their clinical use. Despite a lack of clear signal of activity to date, immunotherapy may offer new perspectives in the treatment of these refractory tumors.

Hypoxia inducible lncRNA-CBSLR modulates ferroptosis through m6A-YTHDF2-dependent modulation of CBS in gastric cancer

IntroductionTumors are usually refractory to anti-cancer therapeutics under hypoxic conditions. However, the underlying molecular mechanism remains to be elucidated. ObjectivesOur study intended to identify hypoxia inducible lncRNAs and their biological function in gastric cancer (GC). MethodsDifferentially expressed lncRNAs were determined by microarray analysis between GC cells exposed to hypoxia (1% O2) and normoxia (21% O2) for 24 h. The expression level of CBSLR was manipulated in several GC cell lines to perform molecular and biological analyses both in vitro and in vivo. ResultsWe identified a hypoxia-induced lncRNA-CBSLR that protected GC cells from ferroptosis, leading to chem-resistance. Mechanically, CBSLR interacted with YTHDF2 to form a CBSLR/YTHDF2/CBS signaling axis that decreased the stability of CBS mRNA by enhancing the binding of YTHDF2 with the m6A-modified coding sequence (CDS) of CBS mRNA. Furthermore, under decreased CBS levels, the methylation of the ACSL4 protein was reduced, leading to protein polyubiquitination and degradation of ACSL4. This, in turn, decreased the pro-ferroptosis phosphatidylethanolamine (PE) (18:0/20:4) and PE (18:0/22:4) content and contributed to ferroptosis resistance. Notably, CBSLR is upregulated, whereas CBS is downregulated in GC tissues compared to matched normal tissues; and GC patients with high CBSLR/low CBS levels have a worse clinical outcome and a poorer response to chemotherapy. ConclusionOur study reveals a novel mechanism in how HIF1α/CBSLR modulates ferroptosis/chemoresistance in GC, illuminating potential therapeutic targets for refractory hypoxic tumors.

SOLITARY FIBROUS SARCOMA: LATE PRESENTATION WITH DIRE EFFECTS

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: A 73-year-old woman with history of breast cancer status post radiation and chemotherapy was eval-uated in our emergency department (ED) for left sided chest pain that worsened over the previous month. She had two weeks of progressive physical limitation, and developed orthopnea the night prior which prompted her to seek care. CASE PRESENTATION: In the ED she was noted to have unrelenting left sided pleuritic chest pain. Physical exam was nota-ble for diminished breath sounds on the left side. Computed tomography (CT) scan of her chest re-vealed a 9.7 x 5.5 cm left lung mass with an associated complex loculated effusion. A left sided chest tube was placed for the loculated pleural effusion. It was exudative by Light's criteria, and pleural flu-id hematocrit was consistent with a hemothorax. She underwent a biopsy of the left lung mass which demonstrated CD34, BCL2, STAT6, spindle cell features and staghorn vasculature indicating a ma-lignant solitary fibrous sarcoma (SFS). She eventually underwent resection as an outpatient once staging confirmed no distant metastatic disease. DISCUSSION: The majority of thoracic solitary fibrous tumors (SFTs) are asymptomatic benign intrathoracic masses discovered incidentally on chest imaging. SFS are a malignant subtype of SFT [1]. Our case demon-strates a rare finding of a large left sided malignant solitary fibrous sarcoma that presented with a large hemothorax. SFTs generally arise from CD34+ dendritic mesenchymal cells which are present in nearly all connective tissues [2]. Association with pleural effusion may be associated with an in-creased risk of a malignant tumor [3]. The presence of a hemothorax has also been reported to cor-relate with rapid tumor enlargement [3]. STAT6, CD34, BCL2 are the most commonly found positive markers, with STAT6 sensitivity being reported as high as 100% [4]. CONCLUSIONS: Our patient did have a history of radiation treatment for left sided breast cancer which has been im-plicated in the development of SFS, particularly in the same radiation fields [5, 6]. Prognosis is usual-ly unpredictable with surgery being the gold standard in treatment [7]. In malignant tumors, chemo-therapy and radiation have limited efficacy [7]. Recurrence rates in malignant SFS are high even with complete resection, reported to be around 63% [8]. REFERENCE #1: Davanzo B, Emerson RE, Lisy M, Koniaris LG, Kays JK. Solitary fibrous tumor. Transl Gastroente-rol Hepatol. 2018 Nov 21;3:94. doi: 10.21037/tgh.2018.11.02. PMID: 30603730; PMCID: PMC6286917. REFERENCE #2: Zuo Z, Zhou H, Sun Y, Mao Q, Zhang Y, Gao X. Rapidly growing solitary fibrous tumors of the pleura: a case report and review of the literature. Ann Transl Med. 2020 Jul;8(14):890. doi: 10.21037/atm-20-4974. PMID: 32793734; PMCID: PMC7396790. REFERENCE #3: Tan JH, Hsu AA. Challenges in diagnosis and management of giant solitary fibrous tumour of pleu-ra: a case report. BMC Pulm Med 2016;16:114. 10.1186/s12890-016-0279-0. REFERENCE #4: Zhang P, Xiong K, Lv P, et al. Malignant solitary fibrous tumor occurring in the mediastinal pleura showing NAB2ex4-STAT6ex2 fusion and negative STAT6 immunohistochemistry: A case report. Thorac Cancer 2020;11:1344-9. 10.1111/1759-7714.13395. REFERENCE #5: Rubino C, Shamsaldin A, Lê MG, Labbé M, Guinebretière JM, Chavaudra J, de Vathaire F. Radia-tion dose and risk of soft tissue and bone sarcoma after breast cancer treatment. Breast Cancer Res Treat. 2005;89(3):277–288. doi: 10.1007/s10549-004-2472-8. REFERENCE #6: Karlsson P, Holmberg E, Johansson KA, Kindblom LG, Carstensen J, Wallgren A. Soft tissue sar-coma after treatment for breast cancer. Radiother Oncol. 1996;38(1):25–31. doi: 10.1016/0167-8140(95)01663-5. REFERENCE #7: Ronchi et al., "Extrapleural Solitary Fibrous Tumor: A Distinct Entity from Pleural Solitary Fibrous Tumor. An Update on Clinical, Molecular and Diagnostic Features. REFERENCE #8: Boothe JT, Budd GT, Smolkin MB, et al. Durable Near-Complete Response to Anti-PD-1 Check-point Immunotherapy in a Refractory Malignant Solitary Fibrous Tumor of the Pleura. Case Rep Oncol 2017;10:998-1005. 10.1159/000484041. DISCLOSURES: No relevant relationships by Danish Ahmad, source=Web Response No relevant relationships by Saad Ashraf, source=Web Response No relevant relationships by Fiyad Haniff, source=Web Response no disclosure on file for Jennifer Toth

Combination of Compound Kushen Injection and cisplatin shows synergistic antitumor activity in p53-R273H/P309S mutant colorectal cancer cells through inducing apoptosis

Ethnopharmacological relevanceColorectal cancer (CRC) is one type of worldwide popular and refractory tumors. Compound Kushen Injection (CKI) is a frequently applied traditional Chinese medicine formula as an adjuvant drug for the chemotherapy of CRC. P53 is the most commonly mutated gene in CRC, accounting for the development, malignant and prognosis progression of CRC. However, effect of CKI on the therapeutic efficacy of p53-mutant CRC remains understood. Besides, the combined efficacy of different chemotherapeutics drugs in combination with CKI for CRC treatment is rarely concerned. Aim of studyTo investigate the combined efficacy of the CKI-derived combination strategies in the p53-mutant CRC. Materials and methodsTwo CRC cell lines HCT116 and SW480 cells, which respectively harbor wild-type p53 and p53-R273H/P309S mutant, were applied. Cisplatin (Cis) and 5-fluorouracil (5FU) were combined chemotherapeutics drugs of CKI-derived combination strategies in this article. In vitro antitumor activity was detected by sulforhodamine B (SRB) assay and colony formation assay. Combenefit soft was applied to evaluate the synergetic/antagonistic effect of drug combination. Lentivirus-mediated overexpression method was used to generate a set of p53-mutant and wild-type CRC cell lines harboring identical genomes. Transcriptomics and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were applied to predicate the underlying mechanism of synergetic interaction between drug combination. Western blot was performed to verify predicated pathways contributing to the synergy of drug combination. ResultsCKI preferentially combined with Cis but not 5FU, to produce a synergistical antitumor efficiency for p53-R273H/P309S mutant, rather than wild-type p53 harboring CRC cells. The combination of CKI and Cis strongly reprogrammed the transcriptional profiles of SW480 cells. Cytokine-cytokine receptor interaction pathway was a key pathway involved in cooperativity between CKI and Cis in SW480 cells. Mechanistically, compared to that Cis individually triggered necroptosis, the co-treatment of CKI and Cis reinforced the cell death of SW480 cells in a possible synergistic manner by inducing extrinsic apoptosis pathway. ConclusionThis article provides a novel perspective into the precision clinical application of CKI-derived combination therapy programs of CRC based on genetic variation and the classes of chemotherapeutics drugs.

Irinotecan Plus Doxorubicin Hydrochloride Liposomes for Relapsed or Refractory Wilms Tumor.

PurposeThe prognosis of relapsed or refractory pediatric Wilms tumor (WT) is dismal, and new salvage therapies are needed. This study aimed to evaluate the efficacy of the combination of irinotecan and a doxorubicin hydrochloride liposome regimen for relapsed or refractory pediatric WT.Patients and MethodsThe present study enrolled relapsed or refractory pediatric WT patients who were treated with the AI regimen (doxorubicin hydrochloride liposomes 40 mg/m2 per day, day 1, and irinotecan 50 mg/m2 per day with 90-min infusion, days 1–5; this regimen was repeated every 3 weeks) at Sun Yat-sen University Cancer Center from July 2018 to September 2020. The response was defined as the best-observed response after at least two cycles according to the Response Evaluation Criteria of Solid Tumors (RECIST 1.1), and toxicity was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE 4.03).ResultsA total of 16 patients (male:female, 8:8) with a median age of 4.2 years (0.5–11 years) with relapsed or refractory disease were enrolled in this study, including 14 patients with relapsed disease and two patients with refractory disease. These patients received 1–8 courses (median, 3 courses) of the AI regimen. Fourteen patients were assessable for response: two with complete response (CR), five with partial response (PR), two with stable disease (SD), and five with progressive disease (PD). The objective response rate was 50% (two CR, five PR), and the disease control rate was 64% (two CR, five PR, and two SD). Seven out of 14 patients (50%) were alive at the last follow-up, ranging from 2.6 to 32.4 months. The median progression-free survival and median overall survival were 3.5 months (range 0.5–12 months) and 8 months (range 1–28 months), respectively. Sixteen patients were assessable for toxicity, with the most common grade 3 or 4 adverse events being alopecia (62%), leukopenia (40%), abdominal pain (38%), diarrhea (23%), and mucositis (16%), etc. No fatal adverse events have been observed, and modest adverse effects can be administered.ConclusionIrinotecan and doxorubicin hydrochloride liposome regimens have positive efficacy on relapsed or refractory pediatric WT with well-tolerated toxicity. A prospective clinical trial is warranted.

Cardiopulmonary bypass does not consequentially contribute to postoperative distant metastasis of giant refractory thoracic tumors: A retrospective study with long-term follow-up.

BackgroundFew clinical research studies with long‐term follow‐up have revealed whether cardiopulmonary bypass (CPB) increases the risk of postoperative distant metastasis in patients with giant refractory thoracic tumors. The present study evaluated the risk of distant metastasis after surgery utilizing CPB with long‐term follow‐up.MethodsClinical data for patients with giant refractory thoracic tumors who underwent resection with the use of CPB in the Second Affiliated Hospital of Soochow University during the past 11 years were retrospectively reviewed.ResultsOf the 14 patients with giant refractory thoracic tumors who had undergone surgery under CPB, 10 patients (71.4%) were completely resected. Twelve patients were followed up for 13–127 months with 10 patients were completely resected and two patients could not be completely resected due to severe tissue invasion. Three patients (25%) suffered from distant metastasis, and four patients (33.3%) experienced local recurrence. Only one patient (1/10) with complete resection suffered from distant metastasis, while two patients (2/10) experienced local recurrence. Two patients (2/2) with major resection suffered from both distant metastasis and local recurrence. Median overall survival for patients who have been regularly followed up was 50 months with 1‐, 5‐, and 10‐year survival of 100%, 75%, and 66.7%. No difference was found between the distant metastasis survival and the local recurrence survival. (p = 0.99).ConclusionsCPB is an effective strategy for complete resection of the giant refractory thoracic tumors with an acceptable risk of postoperative distant metastasis for some patients.

772P Hormonal therapy in pretreated patients with metastatic or refractory ovary granulosa cell tumor

Granulosa cell tumor is a malignant neoplasm that arises from the ovarian sex-cord stromal cell. Surgery is the primary treatment. Recurrence ratios are high in patients who had stage IC or over. In this study, we aimed to assess the efficacy of hormonal therapy in pretreated patients with metastatic or refractory ovary granulosa cell tumors.

Glycogen Metabolism Predicts the Efficacy of Immunotherapy for Urothelial Carcinoma

Urothelial cancer (UC) is one of the common refractory tumors and chemotherapy is the primary treatment for it. The advent of immune checkpoint inhibitors (ICI) has facilitated the development of treatment strategies for UC patients. To screen out UC patients sensitive to ICI, researchers have proposed that PD-L1, tumor mutation burden and TCGA molecular subtypes can be used as predictors of ICI efficacy. However, the performance of these predictors needs further validation. We need to identify novel biomarkers to screen out UC patients sensitive to ICI. In our study, we collected the data of two clinical cohorts: the ICI cohort and the TCGA cohort. The result of the multivariate Cox regression analysis showed that glycogen metabolism score (GMS) (HR = 1.26, p = 0.017) was the negative predictor of prognosis for UC patients receiving ICI treatment. Low-GMS patients had a higher proportion of patients achieving complete response or partial response to ICI. After the comparison of gene mutation status between high-GMS and low-GMS patients, we identified six genes with significant differences in mutation frequencies, which may provide new directions for potential drug targets. Moreover, we analyzed the immune infiltration status and immune-related genes expression between high-GMS and low-GMS patients. A reduced proportion of tumor-associated fibroblasts and elevated proportion of CD8+ T cells can be observed in low-GMS patients while several immunosuppressive molecules were elevated in the high-GMS patients. Using the sequencing data of the GSE164042 dataset, we also found that myeloid-derived suppressor cell and neutrophil related signature scores were lower in α-glucosidase knockout bladder carcinoma cells when compared to the control group. In addition, angiogenesis, classic carcinogenic pathways, immunosuppressive cells related pathways and immunosuppressive cytokine secretion were mainly enriched in high-GMS patients and cell samples from the control group. Finally, we suspected that the combination treatment of ICI and histone deacetylase inhibitors may achieve better clinical responses in UC patients based on the analysis of drug sensitivity data. In conclusion, our study revealed the predictive value of GMS for ICI efficacy of UC patients, providing a novel perspective for the exploration of new drug targets and potential treatment strategies.

The bioactive ingredients in Actinidia chinensis Planch. Inhibit liver cancer by inducing apoptosis

Actinidia chinensis Planch. (ACP) is a common traditional Chinese medicine, which is mostly used for cancer treatment clinically. Liver cancer is a refractory tumor with a high incidence. Although ACP has been reported in the treatment of liver cancer, its possible mechanism of action is little known. The aim of this paper was to investigate the active components of ACP in the treatment of liver cancer and the related mechanisms by a network pharmacology approach. The active components of ACP and the corresponding targets were obtained from multiple databases. Cytoscape software and STRING database were used to build the "herb-component-target (H-C-T)" network and protein-protein interactions (PPI) network. The key components and targets were further predicted by the Cytohubba plug-in in Cytoscape. Then, experiments were carried out on HepG2 cell line and Huh7 cell line to verify the effects and related mechanisms of the key compounds in ACP. 28 active components in ACP and 1299 related targets were screened out according to two indicators, oral bioavailability (OB) and drug-likeness (DL). The key compounds predicted include rutinum, astragalin, and L-epicatechin, and the main signaling pathways focus on apoptosis. Astragalin, a key compound in ACP, could inhibit the expression of Bcl-2, up-regulate the expression of Bax, cleaved caspase 3, cleaved caspase 8, and cleaved caspase 9, and regulate the apoptosis signaling pathway to inhibit the proliferation of liver cancer cells to play a therapeutic role in anti-liver cancer. These results suggest that ACP can alleviate the progression of liver cancer through the mechanisms predicted by network pharmacology, and provide a basis for the further understanding of the application of ACP in anti-cancer.

Immune Checkpoints: Therapeutic Targets for Pituitary Tumors.

Pituitary tumors are the third most common intracranial tumors in adults. Treatment of refractory pituitary tumors is known to be difficult due to limited treatment options. As a promising therapeutic method, tumor immunotherapy has been applied in the treatment of many tumors, including pituitary tumors. Immune checkpoint blocking is one of the effective strategies to activate antitumor immunity. Immune checkpoints prevent tissue damage by regulating the immune response of peripheral tissues and participate in the maintenance of a normal immune environment. In the presence of a tumor, inhibition of T cell activity by tumor cells binding to immune checkpoints and their ligands is an important mechanism for tumor cells to escape immune injury. In this review, we summarize the latest findings of immune checkpoints and their potential as immunotherapeutic targets for pituitary tumors.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

A Small Molecule Strategy for Targeting Cancer Stem Cells in Hypoxic Microenvironments and Preventing Tumorigenesis.

Breast cancer consists of heterogenic subpopulations, which determine the prognosis and response to chemotherapy. Among these subpopulations, a very limited number of cancer cells are particularly problematic. These cells, known as breast cancer stem cells (BCSCs), are thought responsible for metastasis and recurrence. They are thus major contributor to the unfavorable outcomes seen for many breast cancer patients. BCSCs are more prevalent in the hypoxic niche. This is an oxygen-deprived environment that is considered crucial to their proliferation, stemness, and self-renewal but also one that makes BCSCs highly refractory to traditional chemotherapeutic regimens. Here we report a small molecule construct, AzCDF, that allows the therapeutic targeting of BCSCs and which is effective in normally refractory hypoxic tumor environments. A related system, AzNap, has been developed that permits CSC imaging. Several design elements are incorporated into AzCDF, including the CAIX inhibitor acetazolamide (Az) to promote localization in MDA-MB-231 CSCs, a dimethylnitrothiophene subunit as a hypoxia trigger, and a 3,4-difluorobenzylidene curcumin (CDF) as a readily released therapeutic payload. This allows AzCDF to serve as a hypoxia-liable molecular platform that targets BCSCs selectively which decreases CSC migration, retards tumor growth, and lowers tumorigenesis rates as evidenced by a combination of in vitro and in vivo studies. To the best of our knowledge, this is the first time a CSC-targeting small molecule has been shown to prevent tumorigenesis in an animal model.

Impact of hypoxia on the pathogenesis and therapy resistance in multiple myeloma.

Multiple myeloma (MM) is a refractory plasma cell tumor. In myeloma cells, the transcription factor IRF4, the master regulator of plasma cells, is aberrantly upregulated and plays an essential role in oncogenesis. IRF4 forms a positive feedback loop with MYC, leading to additional tumorigenic properties. In recent years, molecular targeted therapies have contributed to a significant improvement in the prognosis of MM. Nevertheless, almost all patients experience disease progression, which is thought to be a result of treatment resistance induced by various elements of the bone marrow microenvironment. Among these, the hypoxic response, one of the key processes for cellular homeostasis, induces hypoxia‐adapted traits such as undifferentiation, altered metabolism, and dissemination, leading to drug resistance. These inductions are caused by ectopic gene expression changes mediated by the activation of hypoxia‐inducible factors (HIFs). By contrast, the expression levels of IRF4 and MYC are markedly reduced by hypoxic stress. Notably, an anti‐apoptotic capability is usually acquired under both normoxic and hypoxic conditions, but the mechanism is distinct. This fact strongly suggests that myeloma cells may survive by switching their dependent regulatory factors from IRF4 and MYC (normoxic bone marrow region) to HIF (hypoxic bone marrow microenvironment). Therefore, to achieve deep remission, combination therapeutic agents, which are complementarily effective against both IRF4‐MYC‐dominant and HIF‐dominated fractions, may become an important therapeutic strategy for MM.