Tumorigenic and Immunosuppressive Effects of Endoplasmic Reticulum Stress in Cancer.

Malignant cells utilize diverse strategies that enable them to thrive under adverse conditions while simultaneously inhibiting the development of anti-tumor immune responses. Hostile microenvironmental conditions within tumor masses, such as nutrient deprivation, oxygen limitation, high metabolic demand, and oxidative stress, disturb the protein-folding capacity of the endoplasmic reticulum (ER), thereby provoking a cellular state of "ER stress." Sustained activation of ER stress sensors endows malignant cells with greater tumorigenic, metastatic, and drug-resistant capacity. Additionally, recent studies have uncovered that ER stress responses further impede the development of protective anti-cancer immunity by manipulating the function of myeloid cells in the tumor microenvironment. Here, we discuss the tumorigenic and immunoregulatory effects of ER stress in cancer, and we explore the concept of targeting ER stress responses to enhance the efficacy of standard chemotherapies and evolving cancer immunotherapies in the clinic.

Suppression of MEHMO Syndrome Mutation in eIF2 by Small Molecule ISRIB.

Dysregulation of cellular protein synthesis is linked to a variety of diseases. Mutations in EIF2S3, encoding the γ subunit of the heterotrimeric eukaryotic translation initiation factor eIF2, cause MEHMO syndrome, an X-linked intellectual disability disorder. Here, using patient-derived induced pluripotent stem cells, we show that a mutation at the C terminus of eIF2γ impairs CDC123 promotion of eIF2 complex formation and decreases the level of eIF2-GTP-Met-tRNAiMet ternary complexes. This reduction in eIF2 activity results in dysregulation of global and gene-specific protein synthesis and enhances cell death upon stress induction. Addition of the drug ISRIB, an activator of the eIF2 guanine nucleotide exchange factor, rescues the cell growth, translation, and neuronal differentiation defects associated with the EIF2S3 mutation, offering the possibility of therapeutic intervention for MEHMO syndrome.

Poly(U)-specific endoribonuclease ENDOU promotes translation of human CHOP mRNA by releasing uORF element-mediated inhibition.

Upstream open reading frames (uORFs) are known to negatively affect translation of the downstream ORF. The regulatory proteins involved in relieving this inhibition are however poorly characterized. In response to cellular stress, eIF2α phosphorylation leads to an inhibition of global protein synthesis, while translation of specific factors such as CHOP is induced. We analyzed a 105-nt inhibitory uORF in the transcript of human CHOP (huORFchop ) and found that overexpression of the zebrafish or human ENDOU poly(U)-endoribonuclease (Endouc or ENDOU-1, respectively) increases CHOP mRNA translation also in the absence of stress. We also found that Endouc/ENDOU-1 binds and cleaves the huORFchop transcript at position 80G-81U, which induces CHOP translation independently of phosphorylated eIF2α. However, both ENDOU and phospho-eIF2α are nonetheless required for maximal translation of CHOP mRNA. Increased levels of ENDOU shift a huORFchop reporter as well as endogenous CHOP transcripts from the monosome to polysome fraction, indicating an increase in translation. Furthermore, we found that the uncapped truncated huORFchop -69-105-nt transcript contains an internal ribosome entry site (IRES), facilitating translation of the cleaved transcript. Therefore, we propose a model where ENDOU-mediated transcript cleavage positively regulates CHOP translation resulting in increased CHOP protein levels upon stress. Specifically, CHOP transcript cleavage changes the configuration of huORFchop thereby releasing its inhibition and allowing the stalled ribosomes to resume translation of the downstream ORF.

Selective involvement of UGGT variant: UGGT2 in protecting mouse embryonic fibroblasts from saturated lipid-induced ER stress.

Secretory proteins and lipids are biosynthesized in the endoplasmic reticulum (ER). The "protein quality control" system (PQC) monitors glycoprotein folding and supports the elimination of terminally misfolded polypeptides. A key component of the PQC system is Uridine diphosphate glucose:glycoprotein glucosyltransferase 1 (UGGT1). UGGT1 re-glucosylates unfolded glycoproteins, to enable the re-entry in the protein-folding cycle and impede the aggregation of misfolded glycoproteins. In contrast, a complementary "lipid quality control" (LQC) system that maintains lipid homeostasis remains elusive. Here, we demonstrate that cytotoxic phosphatidic acid derivatives with saturated fatty acyl chains are one of the physiological substrates of UGGT2, an isoform of UGGT1. UGGT2 produces lipid raft-resident phosphatidylglucoside regulating autophagy. Under the disruption of lipid metabolism and hypoxic conditions, UGGT2 inhibits PERK-ATF4-CHOP-mediated apoptosis in mouse embryonic fibroblasts. Moreover, the susceptibility of UGGT2 KO mice to high-fat diet-induced obesity is elevated. We propose that UGGT2 is an ER-localized LQC component that mitigates saturated lipid-associated ER stress via lipid glucosylation.

Blocking CHOP-dependent TXNIP shuttling to mitochondria attenuates albuminuria and mitigates kidney injury in nephrotic syndrome.

Albuminuria is a hallmark of glomerular disease of various etiologies. It is not only a symptom of glomerular disease but also a cause leading to glomerulosclerosis, interstitial fibrosis, and eventually, a decline in kidney function. The molecular mechanism underlying albuminuria-induced kidney injury remains poorly defined. In our genetic model of nephrotic syndrome (NS), we have identified CHOP (C/EBP homologous protein)-TXNIP (thioredoxin-interacting protein) as critical molecular linkers between albuminuria-induced ER dysfunction and mitochondria dyshomeostasis. TXNIP is a ubiquitously expressed redox protein that binds to and inhibits antioxidant enzyme, cytosolic thioredoxin 1 (Trx1), and mitochondrial Trx2. However, very little is known about the regulation and function of TXNIP in NS. By utilizing Chop-/- and Txnip-/- mice as well as 68Ga-Galuminox, our molecular imaging probe for detection of mitochondrial reactive oxygen species (ROS) in vivo, we demonstrate that CHOP up-regulation induced by albuminuria drives TXNIP shuttling from nucleus to mitochondria, where it is required for the induction of mitochondrial ROS. The increased ROS accumulation in mitochondria oxidizes Trx2, thus liberating TXNIP to associate with mitochondrial nod-like receptor protein 3 (NLRP3) to activate inflammasome, as well as releasing mitochondrial apoptosis signal-regulating kinase 1 (ASK1) to induce mitochondria-dependent apoptosis. Importantly, inhibition of TXNIP translocation and mitochondrial ROS overproduction by CHOP deletion suppresses NLRP3 inflammasome activation and p-ASK1-dependent mitochondria apoptosis in NS. Thus, targeting TXNIP represents a promising therapeutic strategy for the treatment of NS.

Overexpression of Pdx1, reduction of p53, or deletion of CHOP attenuates pancreas hypoplasia in mice with pancreas-specific O-GlcNAc transferase deletion.

Deletion of O-GlcNAc transferase (Ogt) in pancreatic epithelial progenitor cells results in pancreatic hypoplasia at birth, partly due to increased apoptosis during embryonic development. Constitutive loss of Ogt in ß-cells results in increased ER stress and apoptosis, and in the Ogt-deficient pancreas, transcriptomic data previously revealed both tumor suppressor protein p53 and pancreatic duodenal homeobox 1 (Pdx1), key cell survival proteins in the developing pancreas, as upstream regulators of differentially expressed genes. However, the specific roles of these genes in pancreatic hypoplasia are unclear. In this study, we explored the independent roles of p53, ER stress protein CHOP, and Pdx1 in pancreas development and their use in the functional rescue of pancreatic hypoplasia in the context of Ogt loss. Using in vivo genetic manipulation and morphometric analysis, we show that Ogt plays a key regulatory role in pancreas development. Heterozygous, but not homozygous, loss of pancreatic p53 afforded a partial rescue of ß-cell, α-cell, and exocrine cell masses, while whole body loss of CHOP afforded a partial rescue in pancreas weight and a full rescue in exocrine cell mass. However, neither was sufficient to fully mitigate pancreatic hypoplasia at birth in the Ogt-deficient pancreas. Furthermore, overexpression of Pdx1 in the pancreatic epithelium resulted in partial rescues in pancreas weight and ß-cell mass in the Ogt loss background. These findings highlight the requirement of Ogt in pancreas development by targeting multiple proteins such as transcription factor Pdx1 and p53 in the developing pancreas.

The impact of CHOP versus bendamustine on bone mineral density in patients with indolent lymphoma enrolled in the GALLIUM study.

Standard CHOP treatment includes a high cumulative dose of prednisone, and studies have shown increased fracture risk following CHOP. It is unclear whether reductions in bone mineral density (BMD) are caused by glucocorticoids or by the combination with chemotherapy. Our objective was to determine the effect of obinutuzumab (G)/rituximab (R)-bendamustine versus G/R-CHOP on BMD in follicular lymphoma patients. Patients in this GALLIUM post hoc study were ≥60 years old and in complete remission at induction treatment completion (ITC), following treatment with G or R in combination with bendamustine or CHOP. To assess BMD, Hounsfield units (HU) were measured in lumbar vertebra L1 on annual computed tomography. Furthermore, vertebral compression fractures were recorded. Of 173 patients included, 59 (34%) received CHOP and 114 (66%) received bendamustine. At baseline, there was no difference in HU between groups. The mean HU decrease from baseline to ITC was 27.8 after CHOP and 17.3 after bendamustine, corresponding to a difference of 10.4 (95% CI: 3.2-17.6). Vertebral fractures were recorded in 5/59 patients receiving CHOP and in 2/114 receiving bendamustine. CHOP was associated with a significant greater decrease in BMD and more frequent fractures. These results suggest that prophylaxis against BMD loss should be considered.

R-CHOP treatment for patients with advanced follicular lymphoma: Over 15-year follow-up of JCOG0203.

Anti-CD20 antibody in combination with chemotherapy extends overall survival (OS) in untreated advanced-stage follicular lymphoma (FL), yet the optimal associated therapy is unclear. Data on the cumulative incidence of secondary malignancies postrelapse after conventional immunochemotherapy are scarce. A long-term analysis of rituximab combined with cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) as first-line treatment was conducted in a randomised clinical trial. A six-cycle R-CHOP regimen was administered every 2 or 3 weeks without rituximab maintenance. A prespecified evaluation was conducted 15 years after the completion of enrolment, following initial analysis results that showed no significant differences in outcomes at the 3-year mark. In-depth analyses were performed on the cohort of 248 patients with FL who were allocated to the two treatment arms. With a median follow-up period of 15.9 years, the 15-year OS was 76.2%. There were no protocol treatment-related deaths, nor were there any fatal infections attributable to subsequent lymphoma treatment. At 15 years, the cumulative incidence of non-haematological and haematological malignancies was 12.8% and 3.7% respectively. Histological transformation appeared after a median of 8 years. R-CHOP maintains safety and efficacy in patients with advanced FL over extended follow-up, making it a viable first-line option for patients with advanced-stage FL.

miR-616-3p alleviates inflammatory response by targeting C-X-C motif chemokine ligand 5.

C/EBP homologous protein (CHOP) is a key regulator in ER stress-mediated signaling pathway via PERK-dependent unfolded protein response. It has been known that microRNA-616 (miR-616) is produced from the intron of the human DDIT3 gene encoding CHOP and increased by ER stress. However, the role of miR-616 and its targets are not fully addressed yet. Here we try to identify a novel target of miR-616 in human lung epithelial cells. Microarray analysis showed that CXCL5 is the most downregulated gene by miR-616 overexpression in A549 cells. We also found that CXCL5 mRNA and protein levels were significantly reduced by miR-616 mimic in the presence or absence of TNFα, while anti-miR-616 enhanced CXCL5 expression. In addition, miR-616-3p targeting sequence in 3'UTR of CXCL5 was confirmed by luciferase reporter assay suggesting that miR-616-3p directly binds to 3'UTR of CXCL5 and inhibits CXCL5 expression. Finally, we confirmed that conditioned medium from A549 cells treated with TNFα or Streptococcus pneumoniae lysates increased intra-alveolar neutrophil infiltration in a mouse model of pulmonary inflammation, while this induction was significantly reduced in a conditioned medium from cells transfected with miR-616-3p. These results suggest that miR-616-3p can alleviate CXCL5-induced pulmonary inflammatory response via targeting 3'UTR of CXCL5 gene.

Recent insights into the effect of endoplasmic reticulum stress in the pathophysiology of intestinal ischaemia‒reperfusion injury.

Intestinal ischaemia‒reperfusion (I/R) injury is a surgical emergency. This condition is associated with a high mortality rate. At present, there are limited number of efficient therapeutic measures for this injury, and the prognosis is poor. Therefore, the pathophysiological mechanisms of intestinal I/R injury must be elucidated to develop a rapid and specific diagnostic and treatment protocol. Numerous studies have indicated the involvement of endoplasmic reticulum (ER) stress in the development of intestinal I/R injury. Specifically, the levels of unfolded and misfolded proteins in the ER lumen are increased due to unfolded protein response. However, persistent ER stress promotes apoptosis of intestinal mucosal epithelial cells through three signalling pathways in the ER, impairing intestinal mucosal barrier function and leading to the dysfunction of intestinal tissues and distant organ compartments. This review summarises the mechanisms of ER stress in intestinal I/R injury, diagnostic indicators, and related treatment strategies with the objective of providing novel insights into future therapies for this condition.

Phenylbutyric acid inhibits hypoxia-induced trophoblast apoptosis and autophagy in preeclampsia via the PERK/ATF-4/CHOP pathway.

Preeclampsia (PE) is a common pregnancy complication with a high mortality rate. Abnormally activated endoplasmic reticulum stress (ERS) is believed to be responsible for the destruction of key placental cells-trophoblasts. Phenylbutyric acid (4-PBA), an ERS inhibitor, is involved in regulating the development of ERS-related diseases. At present, how 4-PBA affects trophoblasts and its mechanisms is still unclear. In this study, PE cell models were established by stimulating HTR-8/SVneo cells with hypoxia. To verify the underlying mechanisms of 4-PBA on PE, CCT020312, an activator of PERK, was also used. The results showed that 4-PBA restored hypoxia-induced trophoblast viability, inhibited HIF-1α protein expression, inflammation, and PERK/ATF-4/CHOP pathway. Hoechst 33342 staining and flow cytometry results confirmed that 4-PBA decreased hypoxia-induced apoptosis in trophoblasts. The results of the JC-1 analysis and apoptosis initiation enzyme activity assay also demonstrated that 4-PBA inhibited apoptosis related to the mitochondrial pathway. Furthermore, by detecting autophagy in trophoblasts, an increased number of autophagic vesicles, damaged mitochondria, enhanced dansylcadaverine fluorescence, enhanced levels of autophagy proteins Beclin-1, LC3II, and decreased p62 were seen in hypoxia-stimulated cells. These changes were reversed by 4-PBA. Furthermore, it was observed that CCT020312 reversed the effects of 4-PBA on the viability, apoptosis, and autophagosome number of hypoxia-induced trophoblasts. In summary, 4-PBA reduces autophagy and apoptosis via the PERK/ATF-4/CHOP pathway and mitochondrial pathway, thereby restoring the viability of hypoxic trophoblasts. These findings provide a solid evidence base for the use of 4-PBA in PE treatment and guide a new direction for improving the outcomes of patients with PE.

CHOP regulated by METTL14-m6A affects cell cycle arrest and regorafenib sensitivity in HCC cells.

BACKGROUND: Regorafenib, a multi-targeted kinase inhibitor, has been used in the treatment of Hepatocellular carcinoma (HCC). The purpose of this study is to investigate the mechanism of Regorafenib in HCC. METHODS: Regorafenib's impact on the sensitivity of HCC cells was assessed using CCK8. Differential gene expression analysis was performed by conducting mRNA sequencing after treatment with Regorafenib. The m6A methylation status of CHOP and differential expression of m6A methylation-related proteins were assessed by RIP and Western Blot. To explore the molecular mechanisms involved in the therapeutic effects of Regorafenib in HCC and the impact of METTL14 and CHOP on Regorafenib treatment, we employed shRNA/overexpression approaches to transfect METTL14 and CHOP genes, as well as conducted in vivo experiments. RESULTS: Treatment with Regorafenib led to a notable decrease in viability and proliferation of SK-Hep-1 and HCC-LM3 cells. The expression level of CHOP was upregulated after Regorafenib intervention, and CHOP underwent m6A methylation. Among the m6A methylation-related proteins, METTL14 exhibited the most significant downregulation. Mechanistic studies revealed that Regorafenib regulated the cell cycle arrest in HCC through METTL14-mediated modulation of CHOP, and the METTL14/CHOP axis affected the sensitivity of HCC to Regorafenib. In vivo, CHOP enhanced the anticancer effect of Regorafenib. CONCLUSION: The inhibition of HCC development by Regorafenib is attributed to its modulation of m6A expression of CHOP, mediated by METTL14, and the METTL14/CHOP axis enhances the sensitivity of HCC to Regorafenib. These findings provide insights into the treatment of HCC and the issue of drug resistance to Regorafenib.

Modified R-BAC plus BTK inhibitor regimen in newly diagnosed young patients with mantle cell lymphoma: a real-world retrospective study.

To explore the optimal treatment for young patients with untreated mantle cell lymphoma (MCL), we compared the efficacy and safety of R-CHOP/R-DHAP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone/rituximab, dexamethasone, cytarabine and cisplatin) and R-BAP (rituximab, bendamustine, cytarabine, and prednisone) plus BTK (Bruton's tyrosine kinase) inhibitors in newly diagnosed patients. Eighty-three young patients (≤ 65 years old) with newly diagnosed MCL admitted to the First Affiliated Hospital of Zhengzhou University from January 1, 2014, to June 1, 2023, using R-CHOP/R-DHAP or R-BAP plus BTK inhibitor were assessed in this study. The median age at presentation was 60 (42-65) years in 83 patients, including 64 males and 19 females; 59 were treated with R-CHOP/R-DHAP regimen chemotherapy, and 24 were treated with R-BAP in combination with the BTK inhibitor regimen. The median follow-up was 17 months (2-86 months) in 83 patients, and the median PFS (progression-free survival) time was not reached. The CRR (complete response rate) of the R-BAP group was higher than that of the R-CHOP/R-DHAP group (87.5% vs. 54.2%, P = 0.005). The ORR (overall response rate) was not significantly different between the two groups (ORR: 91.7% vs. 84.7%, P = 0.497). The PFS (progression-free survival) of the R-BAP group was longer than that of the R-CHOP/R-DHAP group (P = 0.013), whereas OS was not significantly different between the two groups (P = 0.499). The most common adverse effect in both groups was hematotoxicity, with a higher incidence of grade 3-4 lymphopenia and grade 3-4 thrombocytopenia in the R-BAP group than in the R-CHOP/R-DHAP group (P = 0.015 and P = 0.039). Male sex (HR = 4.257, P = 0.013), LDH (lactate dehydrogenase) ≥ 245 U/L (HR = 3.221, P = 0.012), pleomorphic-blastoid (HR = 2.802, P = 0.043) and R-CHOP/R-DHAP regimen (HR = 7.704, P = 0.047) were independent risk factors for PFS. Ki67 ≥ 30% (HR = 8.539, P = 0.005) was an independent risk factor for OS. First-line treatment with R-BAP in combination with BTK inhibitor improved CRR and prolonged PFS in young patients with mantle cell lymphoma and adverse events were tolerable.

Quality of life assessment in diffuse large B-cell lymphoma (DLBCL) in REFLECT: a prospective, non-interventional, multicenter, German study, assessing Sandoz rituximab in combination with CHOP.

Health-related quality of life (HRQoL) data are important indicators of health status in patients with lymphoma. The objective of this analysis was to assess the impact of treatment with Sandoz rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on HRQoL in treatment-naïve adult patients with diffuse large B-cell lymphoma (DLBCL) included in the prospective, real-world REFLECT study. REFLECT is the first prospective study to assess HRQoL in patients with DLBCL treated with a rituximab biosimilar. HRQoL was assessed via the patient-reported European Organization for Research and Treatment of Cancer Core Quality of Life questionnaire at baseline, mid-treatment (month 3), end of treatment (month 6), and follow-up (months 9 and 12). Subgroup analyses were performed to evaluate the influence of baseline characteristics on HRQoL, and associations between baseline HRQoL and treatment response. HRQoL was assessed in 169 patients. Mean global health status score remained stable from baseline (54.8) to mid-treatment (month 3; 54.7), before steadily improving through to end of treatment (month 6; 61.4), and follow-up month 9 (64.9) and month 12 (68.8). Similar trends were observed across most functional and symptom subscales. Higher cognitive, physical, or role functioning, and less appetite loss, diarrhea, fatigue, or pain at baseline, were all associated with an improved likelihood of reaching a complete versus partial response at the end of treatment. Overall, these findings confirm the HRQoL benefits of R-CHOP therapy in treatment-naïve adult patients with DLBCL, and suggest that baseline HRQoL may be predictive of treatment response.

The integrated stress response-related expression of CHOP due to mitochondrial toxicity is a warning sign for DILI liability.

BACKGROUND AND AIMS: Drug-induced liver injury (DILI) is one of the most frequent reasons for failure of drugs in clinical trials or market withdrawal. Early assessment of DILI risk remains a major challenge during drug development. Here, we present a mechanism-based weight-of-evidence approach able to identify certain candidate compounds with DILI liabilities due to mitochondrial toxicity. METHODS: A total of 1587 FDA-approved drugs and 378 kinase inhibitors were screened for cellular stress response activation associated with DILI using an imaging-based HepG2 BAC-GFP reporter platform including the integrated stress response (CHOP), DNA damage response (P21) and oxidative stress response (SRXN1). RESULTS: In total 389, 219 and 104 drugs were able to induce CHOP-GFP, P21-GFP and SRXN1-GFP expression at 50 µM respectively. Concentration response analysis identified 154 FDA-approved drugs as critical CHOP-GFP inducers. Based on predicted and observed (pre-)clinical DILI liabilities of these drugs, nine antimycotic drugs (e.g. butoconazole, miconazole, tioconazole) and 13 central nervous system (CNS) agents (e.g. duloxetine, fluoxetine) were selected for transcriptomic evaluation using whole-genome RNA-sequencing of primary human hepatocytes. Gene network analysis uncovered mitochondrial processes, NRF2 signalling and xenobiotic metabolism as most affected by the antimycotic drugs and CNS agents. Both the selected antimycotics and CNS agents caused impairment of mitochondrial oxygen consumption in both HepG2 and primary human hepatocytes. CONCLUSIONS: Together, the results suggest that early pre-clinical screening for CHOP expression could indicate liability of mitochondrial toxicity in the context of DILI, and, therefore, could serve as an important warning signal to consider during decision-making in drug development.

Real-world treatment patterns, healthcare resource utilization and costs among patients with peripheral T-cell lymphoma.

Objective: To evaluate treatment patterns, healthcare resource utilization (HRU) and costs among peripheral T-cell lymphoma (PTCL) patients in the USA. Methods: A retrospective cohort study, using the IQVIA PharMetrics® Plus claims database from 1 April 2011 to 30 November 2021, identified PTCL patients receiving systemic treatments. Three mutually exclusive subcohorts were created based on line of therapy (LOT): 1LOT, 2LOT and ≥3LOT. Common treatment regimens, median time on treatment, all-cause and PTCL-related HRU and costs were estimated. Results: Among 189 PTCL patients identified, 61.9% had 1LOT, 21.7% had 2LOT and 16.4% had ≥3LOT. The most common treatment regimens in the 1LOT were CHOP/CHOP-like, CHOEP/CHOEP-like and brentuximab vedotin; monotherapies were most common in the 2LOT and ≥3LOT. All-cause and PTCL-related hospitalizations and prescriptions PPPM increased with increasing LOT. Nearly 70% of total treatment costs were PTCL related. Conclusion: Higher utilization of combination therapies in the 1LOT and monotherapies in subsequent LOTs were observed, alongside high PTCL-related costs.

Peripheral T-cell lymphomas (PTCL) are a rare and fast-growing form of blood cancer. About 8000­12,000 people in the USA are diagnosed with PTCL every year. As it is a rare disease and has many types, and there is a limited understanding of the patients who have PTCL and the treatments they receive in the real world. The purpose of this study was to evaluate how these patients are treated, what are they treated with and what are the costs of these treatments in the USA. The data collected on these patients was divided into three groups based upon the number of lines of treatment/therapy (LOT) they received: 1LOT, 2LOT and ≥3LOT. This study researched different treatments and their duration in each line of therapy. Among 189 PTCL patients included in the study, the average age of patients was 55 years and 62% were male. Among these patients, 62% had 1LOT, 22% had 2LOT and 16% had ≥3LOT. The most common treatments in the 1LOT were traditional chemotherapy regimens followed by targeted therapies: CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) or CHOP-like, CHOEP (cyclophosphamide, doxorubicin, vincristine, etoposide and prednisone) or CHOEP-like, and brentuximab vedotin. Treatment regimens with only one drug were most common in the 2LOT and ≥3LOT. The total cost of PTCL treatment in the USA is very high; 70% of this cost is related to their treatment with various drugs. More research is needed to better understand the treatment and cost of this rare cancer.

Treatment patterns and costs among US patients with diffuse large B-cell lymphoma not treated with 2L stem cell transplantation.

Aim: To assess treatment patterns, healthcare resource utilization (HCRU), and costs for patients with diffuse large B-cell lymphoma (DLBCL) who did not receive stem cell transplantation in second-line. Patients & methods: An administrative MarketScan® database study to assess DLBCL claims from 01/01/2009-30/09/2020. Results: Most patients (n = 750) received rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone in first-line (86.8%) and rituximab (39.5%) or bendamustine ± rituximab ± other (16.3%) in second-line. Over half were hospitalized (mean duration: 16.5 (standard deviation [SD]: 25.8) days per patient per year). Mean medical/pharmacy costs were US$141,532 per patient per year (SD: $189,579), driven by DLBCL-related claims. Conclusion: Healthcare resource utilization and costs for DLBCL-related claims were due to hospitalizations and outpatient visits. Novel therapies to reduce clinical and economic burdens are needed.

Identification of genomic binding sites and direct target genes for the transcription factor DDIT3/CHOP.

DDIT3 is a tightly regulated basic leucine zipper (bZIP) transcription factor and key regulator in cellular stress responses. It is involved in a variety of pathological conditions and may cause cell cycle block and apoptosis. It is also implicated in differentiation of some specialized cell types and as an oncogene in several types of cancer. DDIT3 was originally believed to act as a dominant-negative inhibitor by forming heterodimers with other bZIP transcription factors, preventing their DNA binding and transactivating functions. DDIT3 has, however, been reported to bind DNA and regulate target genes. Here, we employed ChIP sequencing combined with microarray-based expression analysis to identify direct binding motifs and target genes of DDIT3. The results reveal DDIT3 binding to motifs similar to other bZIP transcription factors, known to form heterodimers with DDIT3. Binding to a class III satellite DNA repeat sequence was also detected. DDIT3 acted as a DNA-binding transcription factor and bound mainly to the promotor region of regulated genes. ChIP sequencing analysis of histone H3K27 methylation and acetylation showed a strong overlap between H3K27-acetylated marks and DDIT3 binding. These results support a role for DDIT3 as a transcriptional regulator of H3K27ac-marked genes in transcriptionally active chromatin.

Activation of the PERK-CHOP signaling pathway during endoplasmic reticulum stress contributes to olanzapine-induced dyslipidemia.

Olanzapine (OLZ) is a widely prescribed antipsychotic drug with a relatively ideal effect in the treatment of schizophrenia (SCZ). However, its severe metabolic side effects often deteriorate clinical therapeutic compliance and mental rehabilitation. The peripheral mechanism of OLZ-induced metabolic disorders remains abstruse for its muti-target activities. Endoplasmic reticulum (ER) stress is implicated in cellular energy metabolism and the progression of psychiatric disorders. In this study, we investigated the role of ER stress in the development of OLZ-induced dyslipidemia. A cohort of 146 SCZ patients receiving OLZ monotherapy was recruited, and blood samples and clinical data were collected at baseline, and in the 4th week, 12th week, and 24th week of the treatment. This case-control study revealed that OLZ treatment significantly elevated serum levels of endoplasmic reticulum (ER) stress markers GRP78, ATF4, and CHOP in SCZ patients with dyslipidemia. In HepG2 cells, treatment with OLZ (25, 50 µM) dose-dependently enhanced hepatic de novo lipogenesis accompanied by SREBPs activation, and simultaneously triggered ER stress. Inhibition of ER stress by tauroursodeoxycholate (TUDCA) and 4-phenyl butyric acid (4-PBA) attenuated OLZ-induced lipid dysregulation in vitro and in vivo. Moreover, we demonstrated that activation of PERK-CHOP signaling during ER stress was a major contributor to OLZ-triggered abnormal lipid metabolism in the liver, suggesting that PERK could be a potential target for ameliorating the development of OLZ-mediated lipid dysfunction. Taken together, ER stress inhibitors could be a potentially effective intervention against OLZ-induced dyslipidemia in SCZ.

Oncoprotein LAMTOR5-mediated CHOP silence via DNA hypermethylation and miR-182/miR-769 in promotion of liver cancer growth.

C/EBP homologous protein (CHOP) triggers the death of multiple cancers via endoplasmic reticulum (ER) stress. However, the function and regulatory mechanism of CHOP in liver cancer remain elusive. We have reported that late endosomal/lysosomal adapter, mitogen-activated protein kinase and mTOR activator 5 (LAMTOR5) suppresses apoptosis in various cancers. Here, we show that the transcriptional and posttranscriptional inactivation of CHOP mediated by LAMTOR5 accelerates liver cancer growth. Clinical bioinformatic analysis revealed that the expression of CHOP was low in liver cancer tissues and that its increased expression predicted a good prognosis. Elevated CHOP contributed to destruction of LAMTOR5-induced apoptotic suppression and proliferation. Mechanistically, LAMTOR5-recruited DNA methyltransferase 1 (DNMT1) to the CpG3 region (-559/-429) of the CHOP promoter and potentiated its hypermethylation to block its interaction with general transcription factor IIi (TFII-I), resulting in its inactivation. Moreover, LAMTOR5-enhanced miR-182/miR-769 reduced CHOP expression by targeting its 3'UTR. Notably, lenvatinib, a first-line targeted therapy for liver cancer, could target the LAMTOR5/CHOP axis to prevent liver cancer progression. Accordingly, LAMTOR5-mediated silencing of CHOP via the regulation of ER stress-related apoptosis promotes liver cancer growth, providing a theoretical basis for the use of lenvatinib for the treatment of liver cancer.