CBL mutations drive PI3K/AKT signaling via increased interaction with LYN and PIK3R1

Recent progress and future challenges in structure-based protein-protein interaction prediction

Protein-protein interactions (PPIs) play a fundamental role in cellular processes, and understanding these interactions is crucial for advances in both basic biological science and biomedical applications. This review presents an overview of recent progress in computational methods for modeling protein complexes and predicting PPIs based on 3D structures, focusing on the transformative role of artificial intelligence-based approaches. We further discuss the expanding biomedical applications of PPI research, including the elucidation of disease mechanisms, drug discovery, and therapeutic design. Despite these advances, significant challenges remain in predicting host-pathogen interactions, interactions between intrinsically disordered regions, and interactions related to immune responses. These challenges are worthwhile for future explorations and represent the frontier of research in this field.

Locking CBL TKBD in its native conformation presents a novel therapeutic opportunity in mutant CBL-dependent leukemia

Casitas B-lineage lymphoma (CBL) is an E3 ubiquitin ligase critical for negatively regulating receptor protein tyrosine kinases (RTKs). Deleterious CBL mutants lose E3 activity, but act as adaptors that gain function to cause myeloproliferative neoplasms. Currently, there is no targeted treatment available for patients with CBL mutant-dependent disorders. By combining phage-display technology and structure-based optimization, we discovered CBLock, a nanomolar affinity peptide inhibitor, that binds the substrate-binding site of CBL's tyrosine kinase binding domain (TKBD). CBLock disrupts the interaction between CBL mutants and RTKs, thereby impairing RTK-mediated priming of adaptor function of CBL mutants and downstream signaling. Notably, CBLock binds TKBD without inducing conformational changes, thereby preserving its ligand-free native conformation. In contrast, when CBL binds RTK substrates, TKBD undergoes a conformational change. Maintaining the native CBL TKBD conformation was crucial for CBLock to inhibit proliferation, induce cell-cycle arrest, and promote apoptosis in leukemia cells harboring CBL mutations. In a mouse xenograft model of acute myeloid leukemia (AML), CBLock reduced tumor burden and improved survival rate. Moreover, CBLock inhibited the proliferation of cells derived from patients with CBL mutations. Therefore, inhibiting CBL TKBD in its native state presents a promising therapeutic opportunity in targeting mutant CBL-dependent leukemia.

SOHO State of the Art Updates and Next Questions. Atypical Chronic Myeloid Leukemia: Pathogenesis, Diagnostic Challenges, and Therapeutic Strategies

Atypical chronic myeloid leukemia (aCML) is a rare and challenging clonal hematopoietic disorder within the myelodysplastic/myeloproliferative neoplasm (MDS/MPN) spectrum. Over the past two decades, substantial progress has been made in understanding the genetic mechanisms driving aCML, revealing a complex and heterogeneous mutational landscape. Key ancestral mutations, such as ASXL1 and ETNK1, have been identified, providing a foundation for the pathogenesis and for the possible emergence of secondary abnormalities, particularly in epigenetic regulation (eg, SETBP1), and in splicing process (eg, SRSF2). These molecular insights have been integrated into current diagnostic classifications, refining disease characterization and offering potential targets for precision therapies. Despite these advances, significant clinical challenges persist due to the disease's rarity and the lack of randomized clinical trials. Therapeutic strategies remain inadequately defined, with allogeneic stem cell transplantation being the only curative option. This review provides an overview of the molecular, clinical, and therapeutic information that may pave the way for essential advancements in the proper management of this disease.

Analysis and identification of potential biomarkers for dysfunctional uterine bleeding

Clinical evidence increasingly suggests that traditional treatments for dysfunctional uterine bleeding (DUB) have limited success. In this study, blood samples from 10 DUB patients and 10 healthy controls were collected for transcriptome sequencing. Then, the differentially expressed genes (DEGs) were screened and crossed with the DUB-related module genes to obtain the target genes. These target genes were analyzed for functional enrichment. Further, the biomarkers were screened by protein-protein interaction (PPI) analysis and analyzed by the gene set enrichment analysis (GSEA) and ingenuity pathway analysis (IPA). To explore the pathogenesis of DUB, immune microenvironment analyses were also performed. Potential drugs targeting these biomarkers were predicted for clinical treatment. The expression of these biomarkers was validated using quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that, a total of 754 target genes were found to be related to cell proliferation and senescence. Five biomarkers-CENPE, KIF11, PIK3R1, SMC3, and SMC4-were identified, all of which were down-regulated in the DUB group, and most of these findings were confirmed by qRT-PCR. Notably, CENPE expression showed a negative association with activated NK cells and a positive association with resting NK cells. In addition, 44 potential drugs were predicted for DUB treatment. In conclusion, five DUB biomarkers were identified, enhancing understanding of gene regulation in DUB and providing a theoretical foundation for clinical diagnosis and treatment.

scPharm: Identifying Pharmacological Subpopulations of Single Cells for Precision Medicine in Cancers

Intratumour heterogeneity significantly hinders the efficacy of anticancer therapies. Compared with drug perturbation experiments, which yield pharmacological data at the bulk cell level, single-cell RNA sequencing (scRNA-seq) technology provides a means to capture molecular heterogeneity at single-cell resolution. Here, scPharm is introduced, a computational framework that integrates pharmacological profiles with scRNA-seq data to identify pharmacological subpopulations of cells within a tumour and prioritize tailored drugs. scPharm uses the normalized enrichment scores (NESs) determined from gene set enrichment analysis to assess the distribution of cell identity genes in drug response-determined gene lists. Based on the strong correlation between the NES and drug response at single-cell resolution, scPharm successfully identified the sensitive subpopulations in ER-positive and HER2-positive human breast cancer tissues, revealed dynamic changes in the resistant subpopulation of human PC9 cells treated with erlotinib, and expanded its ability to a mouse model. Its superior performance and computational efficiency are confirmed through comparative evaluations with other single-cell prediction tools. Additionally, scPharm predicted combination drug strategies by gauging compensation or booster effects between drugs and evaluated drug toxicity in healthy cells in the tumour microenvironment. Overall, scPharm provides a novel approach for precision medicine in cancers by revealing therapeutic heterogeneity at single-cell resolution.

Autoinflammation in patients with leukocytic CBL loss of heterozygosity is caused by constitutive ERK-mediated monocyte activation

Patients heterozygous for germline CBL loss-of-function (LOF) variants can develop myeloid malignancy, autoinflammation, or both, if some or all of their leukocytes become homozygous for these variants through somatic loss of heterozygosity (LOH) via uniparental isodisomy. We observed an upregulation of the inflammatory gene expression signature in whole blood from these patients, mimicking monogenic inborn errors underlying autoinflammation. Remarkably, these patients had constitutively activated monocytes that secreted 10 to 100 times more inflammatory cytokines than those of healthy individuals and CBL LOF heterozygotes without LOH. CBL-LOH hematopoietic stem and progenitor cells (HSPCs) outgrew the other cells, accounting for the persistence of peripheral monocytes homozygous for the CBL LOF variant. ERK pathway activation was required for the excessive production of cytokines by both resting and stimulated CBL-LOF monocytes, as shown in monocytic cell lines. Finally, we found that about 1 in 10,000 individuals in the UK Biobank were heterozygous for CBL LOF variants and that these carriers were at high risk of hematological and inflammatory conditions.

Case of B-acute lymphoblastic leukaemia with t(1;19)(q23;p13.3) TCF3::PBX1 and co-occurring CBL mutation in an elderly patient

The t(1;19) (q23;p13) TCF3::PBX1 is a well-described, recurring chromosomal abnormality in B-acute lymphoblastic leukaemia (B-ALL) that has historically been associated with a worse prognosis in paediatric patients. Gene expression profiling has demonstrated that TCF3::PBX1 results in a distinct subtype of B-ALL, leading to its recognition in the most recent WHO and ICC classifications. Though initially believed to be a poor prognostic sign in the adult population, emerging evidence suggests its presence may instead be intermediate or even favourable in B-ALL. However, adults with TCF3::PBX1 are typically younger and often qualify for treatment with paediatric-inspired regimens. Thus, the prognostic significance in this population remains unclear. This translocation appears to be very rare in older adults with B-ALL and its predictive and prognostic nature in this population is unknown. Herein, we explore a case of this translocation occurring in a patient in her 70s. She initially presented to the emergency department with abdominal pain and thrombocytopenia and was subsequently diagnosed with B-ALL. In addition to t(1;19) (q23;p13), a pathologic mutation in the CBL gene was identified. CBL mutations have been implicated in cancer progression and are mostly described in paediatric B-ALL. She was treated with modified Ph-negative EWALL induction (Vincristine, Idarubicin, dexamethasone) and achieved a complete remission. However, she subsequently experienced an early relapse and was refractory to targeted therapy with blinatumomab. After treatment with inotuzumab ozogamicin, she achieved a second complete remission. Unfortunately, she then suffered a central nervous system (CNS) relapse and passed away from complications of her disease. This case serves as an example of the heterogeneous nature of B-ALL. It demonstrates that patients with ostensibly favourable prognostic factors may experience poor response rates to traditional chemotherapy as well as targeted salvage agents. It also illustrates the challenges of treating B-ALL in the elderly population.

Exploiting the potential of the ubiquitin-proteasome system in overcoming tyrosine kinase inhibitor resistance in chronic myeloid leukemia

The advent of tyrosine kinase inhibitors (TKI) targeting BCR-ABL has drastically changed the treatment approach of chronic myeloid leukemia (CML), greatly prolonged the life of CML patients, and improved their prognosis. However, TKI resistance is still a major problem with CML patients, reducing the efficacy of treatment and their quality of life. TKI resistance is mainly divided into BCR-ABL-dependent and BCR-ABL-independent resistance. Now, the main clinical strategy addressing TKI resistance is to switch to newly developed TKIs. However, data have shown that these new drugs may cause serious adverse reactions and intolerance and cannot address all resistance mutations. Therefore, finding new therapeutic targets to overcome TKI resistance is crucial and the ubiquitin-proteasome system (UPS) has emerged as a focus. The UPS mediates the degradation of most proteins in organisms and controls a wide range of physiological processes. In recent years, the study of UPS in hematological malignant tumors has resulted in effective treatments, such as bortezomib in the treatment of multiple myeloma and mantle cell lymphoma. In CML, the components of UPS cooperate or antagonize the efficacy of TKI by directly or indirectly affecting the ubiquitination of BCR-ABL, interfering with CML-related signaling pathways, and negatively or positively affecting leukemia stem cells. Some of these molecules may help overcome TKI resistance and treat CML. In this review, the mechanism of TKI resistance is briefly described, the components of UPS are introduced, existing studies on UPS participating in TKI resistance are listed, and UPS as the therapeutic target and strategies are discussed.

Immunological and hematological findings as major features in a patient with a new germline pathogenic CBL variant

Casitas B-lineage lymphoma (CBL) encodes an adaptor protein with E3-ligase activity negatively controlling intracellular signaling downstream of receptor tyrosine kinases. Somatic CBL mutations play a driver role in a variety of cancers, particularly myeloid malignancies, whereas germline defects in the same gene underlie a RASopathy having clinical overlap with Noonan syndrome (NS) and predisposing to juvenile myelomonocytic leukemia and vasculitis. Other features of the disorder include cardiac defects, postnatal growth delay, cryptorchidism, facial dysmorphisms, and predisposition to develop autoimmune disorders. Here we report a novel CBL variant (c.1202G>T; p.Cys401Phe) occurring de novo in a subject with café-au-lait macules, feeding difficulties, mild dysmorphic features, psychomotor delay, autism spectrum disorder, thrombocytopenia, hepatosplenomegaly, and recurrent hypertransaminasemia. The identified variant affects an evolutionarily conserved residue located in the RING finger domain, a known mutational hot spot of both germline and somatic mutations. Functional studies documented enhanced EGF-induced ERK phosphorylation in transiently transfected COS1 cells. The present findings further support the association of pathogenic CBL variants with immunological and hematological manifestations in the context of a presentation with only minor findings reminiscent of NS or a clinically related RASopathy.

CD58 Alterations Govern Antitumor Immune Responses by Inducing PDL1 and IDO in Diffuse Large B-Cell Lymphoma

Recurrent abnormalities in immune surveillance-related genes affect the progression of diffuse large B-cell lymphoma (DLBCL) and modulate the response to therapeutic interventions. CD58 interacts with the CD2 receptor on T cells and NK cells and is recurrently mutated and deleted in DLBCL, suggesting that it may play a role in regulating antitumor immunity. In this study, we comprehensively analyzed the genomic characteristics of CD58 through targeted next-generation sequencing, RNA sequencing (RNA-seq), whole-exome sequencing, and single-cell RNA-seq in patients with newly diagnosed DLBCL. The CD58 mutation rate was 9.1%, and the copy number loss rate was 44.7% among all enrolled patients with DLBCL. Notably, CD58 genetic alterations, along with low CD58 expression, significantly correlated with reduced rates of response to R-CHOP therapy and inferior progression-free survival and overall survival. Single-cell RNA-seq revealed that CD58 expression in tumor cells was negatively correlated with CD8+ T-cell exhaustion/dysfunction status. Insufficient T-cell activation resulting from CD58 alterations could not be attributed solely to CD2 signaling. CD58 inhibited the activity of the JAK2/STAT1 pathway by activating the LYN/CD22/SH2 domain-containing phosphatase 1 (SHP1) axis, thereby limiting PDL1 and IDO expression. Elevated PDL1 and IDO expression in CD58-deficient DLBCL cells led to immune evasion and tumor-intrinsic resistance to chimeric antigen receptor T-cell therapy. Direct activation of CD58-CD2 costimulatory signaling in combination with anti-PDL1 blockade or IDO inhibitor sensitized CD58-deficient DLBCL to chimeric antigen receptor T-cell therapy. Collectively, this work identified the multiple roles of CD58 in regulating antitumor immune responses in DLBCL. Significance: Loss of CD58 mediates immune evasion and therapy resistance in diffuse large B-cell lymphoma by upregulating PDL1 and IDO through LYN/CD22/SHP1 signaling, providing potential targets and therapeutic strategies to improve patient treatment.

Association between CBL gene polymorphism and susceptibility of microscopic polyangiitis in a Chinese population: A case-control analysis

OBJECTIVE

To assess whether Casitas B-lineage lymphoma (CBL) gene polymorphism influences the risk of microscopic polyangiitis (MPA) in Chinese populations.

METHODS

In total, 266 MPA patients and 297 healthy controls were recruited for a case-control study. Five CBL SNPs were genotyped using multiplex polymerase chain reaction and high-throughput sequencing. The relationship between SNPs and the risk of MPA under different genetic models was evaluated by SNPstats. SNP-SNP interaction was analyzed by generalized multifactor dimensionality reduction (GMDR). Finally, the association between CBL SNPs and treatment effects were assessed.

RESULTS

The results showed that CBL rs2276083 was associated with decreasing MPA risk under dominant (OR: 0.53; p = 0.014) and recessive models (OR: 0.52; p = 0.0034). Stratification analysis indicated that rs2276083 and rs2509671 in age < 60 years, rs2276083 in female or in Han population were protective factors for MPA. The CBL haplotype (A-A-G-C-T) was associated with an increased risk of MPA. GMDR suggested that CBL rs2276083, phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PI3KCA) rs1607237, and autophagy-related gene 7 (ATG7) rs7549008 might interact with each other in MPA development (p = 0.0107). CBL rs1047417 with AG genotype and rs11217234 with AG genotype had better clinical treatment effects than other two genotypes (p = 0.048 and p = 0.025, respectively).

CONCLUSION

The genetic polymorphism of CBL had a potential association with the risk of MPA and clinical treatment effects in Guangxi population in China.

Insights into the role of derailed endocytic trafficking pathway in cancer: From the perspective of cancer hallmarks

The endocytic trafficking pathway is a highly organized cellular program responsible for the regulation of membrane components and uptake of extracellular substances. Molecules internalized into the cell through endocytosis will be sorted for degradation or recycled back to membrane, which is determined by a series of sorting events. Many receptors, enzymes, and transporters on the membrane are strictly regulated by endocytic trafficking process, and thus the endocytic pathway has a profound effect on cellular homeostasis. However, the endocytic trafficking process is typically dysregulated in cancers, which leads to the aberrant retention of receptor tyrosine kinases and immunosuppressive molecules on cell membrane, the loss of adhesion protein, as well as excessive uptake of nutrients. Therefore, hijacking endocytic trafficking pathway is an important approach for tumor cells to obtain advantages of proliferation and invasion, and to evade immune attack. Here, we summarize how dysregulated endocytic trafficking process triggers tumorigenesis and progression from the perspective of several typical cancer hallmarks. The impact of endocytic trafficking pathway to cancer therapy efficacy is also discussed.

Long non-coding RNA small nucleolar RNA host gene 29 drives chronic myeloid leukemia progression via microRNA-483-3p/Casitas B-lineage Lymphoma axis-mediated activation of the phosphoinositide 3-kinase/Akt pathway

The aberrant expression of the long non-coding RNA (lncRNA) Small Nucleolar RNA Host Gene 29 (SNHG29) has been associated with various human cancers. However, the role of SNHG29 in chronic myeloid leukemia (CML) remains elusive. Therefore, this study aimed to investigate the function of SNHG29 in CML and unveil its potential underlying mechanisms. Herein, peripheral blood samples from 44 CML patients and 17 healthy subjects were collected. The expressions of SNHG29, microRNA-483-3p (miR-483-3p), and Casitas B-lineage Lymphoma (CBL) were measured using quantitative polymerase chain reaction (qPCR) or Western Blot. Cell viability, apoptosis, and cell cycle progression were evaluated using the Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine incorporation, and flow cytometry, respectively. Western Blot analysis was employed to assess protein expressions related to cellular proliferation, apoptosis, and oncogenesis. RNA immunoprecipitation and dual-luciferase reporter assays were utilized to verify the interactions among SNHG29, miR-483-3p, and CBL. SNHG29 was significantly overexpressed in both blood samples of CML patients and CML cell lines. In CML, increased expression of SNHG29 was positively correlated with clinical staging, and patients with high SNHG29 expression had poorer survival outcomes. Functionally, knocking down SNHG29 effectively inhibited CML cell proliferation and promoted apoptosis. Mechanistically, SNHG29 acted as a competing endogenous RNA for miR-483-3p to modulate CBL expression, thereby activating the Phosphoinositide 3-Kinase/Akt signaling pathway and mediating CML progression. In summary, these findings reveal that SNHG29 promotes tumorigenesis in CML, offering a potential therapeutic strategy for CML treatment.

LncRNA AL645608.3 mediates malignant progression of acute myeloid leukemia

OBJECTIVE

To investigate the role of lncRNA AL645608.3 in the malignant progression of acute myeloid leukemia (AML) cells and explore relevant molecular mechanisms.

METHODS

The expression level of AL645608.3 was measured in AML cell lines (THP-1, HL-60, KG-1, and AML-193) via real-time quantitative polymerase chain reaction (RT-qPCR). Small hairpin RNA (shRNA) and open reading frame of AL645608.3 were cloned into lentiviral vectors and were infected into THP-1 and AML-193 cells. The expression of casitas B-lineage lymphoma (CBL), interferon regulatory factor 6 (IRF6), and interferon beta 1 (IFNB1) was detected through RT-qPCR, and western blot. Co-immunoprecipitation (Co-IP) on IRF6 was conducted. Matrix metalloprotease-9 (MMP-9) activity was evaluated via gelatin zymography assay.

RESULTS

LncRNA AL645608.3 was expressed in the four AML cell lines (THP-1, HL-60, KG-1, and AML-193). Silencing AL645608.3 mitigated the expression of IRF6 and IFNB1 but elevated the expression of CBL in THP-1 cells. Oppositely, AL645608.3 overexpression up-regulated the expression of IRF6 and IFNB1 but decreased the expression of CBL in AML-193 cells. Co-IP results proved that AL645608.3 could directly mediate IRF6 activity in THP-1 and AML-193 cells. MMP-9 activity was decreased by AL645608.3 knockdown and was improved by AL645608.3 overexpression in AML-193 cells.

CONCLUSION

AL645608.3 is expressed in different AML cell lines, and mediates the expression of CBL, IRF6, IFNB1, and MMP-9. These findings might deepen our comprehension of the molecular mechanisms underlying AML.

Myeloproliferative Neoplasms: Diseases Mediated by Chronic Activation of Signal Transducer and Activator of Transcription (STAT) Proteins

Myeloproliferative neoplasms (MPNs) are hematopoietic diseases characterized by the clonal expansion of single or multiple lineages of differentiated myeloid cells that accumulate in the blood and bone marrow. MPNs are grouped into distinct categories based on key clinical presentations and distinctive mutational hallmarks. These include chronic myeloid leukemia (CML), which is strongly associated with the signature BCR::ABL1 gene translocation, polycythemia vera (PV), essential thrombocythemia (ET), and primary (idiopathic) myelofibrosis (PMF), typically accompanied by molecular alterations in the JAK2, MPL, or CALR genes. There are also rarer forms such as chronic neutrophilic leukemia (CNL), which involves mutations in the CSF3R gene. However, rather than focusing on the differences between these alternate disease categories, this review aims to present a unifying molecular etiology in which these overlapping diseases are best understood as disruptions of normal hematopoietic signaling: specifically, the chronic activation of signaling pathways, particularly involving signal transducer and activator of transcription (STAT) transcription factors, most notably STAT5B, leading to the sustained stimulation of myelopoiesis, which underpins the various disease sequalae.

Echinacoside regulates PI3K/AKT/HIF-1α/VEGF cross signaling axis in proliferation and apoptosis of breast cancer

CONTEXT

Echinacoside (ECH) is a natural anti-cancer compound and is of great value in cancer treatment. However, the mechanism underlying this effect on breast cancer (BC) was unclear.

OBJECTIVE

To explore the mechanism of ECH treating BC by network pharmacology and experimental validation.

MATERIALS & METHODS

Several databases were searched to screen potential targets of ECH and obtain information on targets related to BC. STRING was applied to construct a Protein-protein interaction (PPI) network. DAVID was applied for Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Gene Expression Profiling Interactive Analysis (GEPIA) was searched for the relationship between the expression profile and overall survival of major targets in normal breast and BC tissues. Finally, the results of network pharmacology analysis were validated by experiments.

RESULTS

Seventeen targets of ECH overlapped with targets in BC. Ten hub targets were determined through PPI. By GO and KEGG analysis 15 entries and 25 pathways were obtained, in which phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), hypoxia inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) played greater roles. Validation of key targets in the GEPIA database showed that PIK3R1 and PIK3CD remained consistent with the results of the study. Experiments in vitro showed ECH inhibited proliferation, induced apoptosis and reduced mRNA levels and protein expression of PI3K, AKT, hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGFA) in MCF-7 cells. Furthermore, experiments in vivo revealed that ECH significantly reduced tumor growth, promoted apoptosis and decreased the related mRNA levels and protein expression, suggesting ECH works on BC by regulating PI3K/AKT/HIF-1α/VEGF signaling pathway.

DISCUSSION & CONCLUSION

In summary, ECH played an important role in anti-BC by regulating PI3K/AKT/HIF-1α/VEGF signaling pathway. Furthermore, ECH had multi-target and multi-pathway effects, which may be a promising natural compound for treating BC.

Clinical significance of genetic profiling based on different anatomic sites in patients with mucosal melanoma who received or did not receive immune checkpoint inhibitors

BACKGROUND

To date, data on the efficacy of targeted therapies for mucosal melanoma (MM) are limited. In this study, we analyzed genetic alterations according to the primary site of origin, which could provide clues for targeted therapy for MM.

METHODS

We conducted a retrospective cohort study of 112 patients with MM. Targeted sequencing was performed to analyze genetic aberrations. Kaplan-Meier analysis was conducted with the log-rank test to compare the significance among subgroups.

RESULTS

In total, 112 patients with MM were included according to the anatomic sites: 38 (33.9%) in the head and neck, 22 (19.6%) in the genitourinary tract, 21 (18.8%) in the anorectum, 19 (17.0%) in the esophagus, 10 (8.9%) in the uvea, and 2 (1.8%) in the small bowel. The most significantly mutated genes included BRAF (17%), KIT (15%), RAS (15%), TP53 (13%), NF1 (12%), SF3B1 (11%), GNA11 (7%), GNAQ (5%), and FBXW7 (4%). A large number of chromosomal structural variants was found. The anatomic sites of esophagus and small bowel were independent risk factors for progression-free survival (PFS, hazard ratio [HR] 4.78, 95% confidence interval [CI] 2.42-9.45, P < 0.0001) and overall survival (OS, HR 5.26, 95% CI 2.51-11.03, P < 0.0001). Casitas B-lineage lymphoma (CBL) mutants showed significantly poorer PFS and OS. In contrast, MM patients who received immune checkpoint inhibitors (ICIs) had a significantly more favorable OS (HR 0.39, 95% CI 0.20-0.75, P = 0.008).

CONCLUSIONS

Our findings reveal the genetic features of patients with MM, mainly across six anatomic sites, offering a potential avenue for targeted therapies.

Endocytosis in cancer and cancer therapy

Endocytosis is a complex process whereby cell surface proteins, lipids and fluid from the extracellular environment are packaged, sorted and internalized into cells. Endocytosis is also a mechanism of drug internalization into cells. There are multiple routes of endocytosis that determine the fate of molecules, from degradation in the lysosomes to recycling back to the plasma membrane. The overall rates of endocytosis and temporal regulation of molecules transiting through endocytic pathways are also intricately linked with signalling outcomes. This process relies on an array of factors, such as intrinsic amino acid motifs and post-translational modifications. Endocytosis is frequently disrupted in cancer. These disruptions lead to inappropriate retention of receptor tyrosine kinases on the tumour cell membrane, changes in the recycling of oncogenic molecules, defective signalling feedback loops and loss of cell polarity. In the past decade, endocytosis has emerged as a pivotal regulator of nutrient scavenging, response to and regulation of immune surveillance and tumour immune evasion, tumour metastasis and therapeutic drug delivery. This Review summarizes and integrates these advances into the understanding of endocytosis in cancer. The potential to regulate these pathways in the clinic to improve cancer therapy is also discussed.

[CBL inhibits proliferation and invasion of breast cancer cells by ubiquitylation-mediated degradation of NCK2]

OBJECTIVE

To observe the effects of Casitas B lymphoma (CBL) protein on proliferation, migration and invasion of breast cancer cells and explore its mechanism of action.

METHODS

Cultured breast cancer cell lines MDA-MB-231 and MCF7A were transfected with a CBL-overexpressing plasmid and a specific siRNA targeting CBL (siRNA-CBL), respectively, and the changes in cell proliferation, migration and invasion were examined using colony-forming assay, cell counting kit-8 (CCK-8), scratch test and Transwell assay. Flow cytometry and Western blotting were performed to examine the effects of CBL overexpression on cell cycle and epithelial-mesenchymal transition (EMT) of MDA-MB-231 cells, and the changes in the number of filamentous pseudopodia were observed by rhodamine- labeled phalloidin staining of the cytoskeleton. IP-mass spectrometry identified NCK2 as the interacting proteins of CBL, and their interaction was verified by immunoprecipitation and immunofluorescence co-localization experiments in HEK-293T cells transfected with the plasmids for overexpression of CBL, NCK2, or both. Cycloheximide tracking and ubiquitination assays were used for assessing the effects of CBL on stability and ubiquitination of NCK2 protein in MDA-MB-231 cells; CCK-8 and Transwell assays were used to determine the effect of NCK2 overexpression on CBL-mediated proliferation and migration of the cells.

RESULTS

The proliferation, migration and invasion were significantly suppressed in MDA-MB-231 cells overexpressing CBL (P < 0.05) and significantly enhanced in MCF7 cells with CBL silencing (P < 0.01). Silencing of CBL promoted G1/S transition in MCF7 cells (P < 0.05). Overexpression of CBL significantly decreased the expressions of CDK2/4 (P < 0.01), cyclinA2/B1/D1/D3/E2 (P < 0.05), Snail, N-cadherin, claudin-1 (P < 0.05), and upregulated the expression of E-cadherin (P < 0.05). CBL silencing upregulated the expressions of CDK2/4/6 (P < 0.05), cyclin A2/B1/D1/D3/E2 (P < 0.05), Snail, vimentin, and claudin-1 (P < 0.05) and down-regulated E-cadherin expression (P < 0.05). CBL overexpression obviously reduced the number of filamentous pseudopodia in MDA-MB-231 cells, and the reverse changes were observed in MCF7 cells with CBL silencing. In MDA-MB-231 cells, CBL overexpression lowered NCK2 protein stability (P < 0.05) and promoted its ubiquitin-mediated degradation (P < 0.01). Overexpression of NCK2 obviously reversed CBL-mediated inhibition of cell proliferation and migration (P < 0.01).

CONCLUSION

CBL can inhibit the proliferation, migration and invasion of breast cancer cells through ubiquitination-mediated degradation of NCK2.

TRPV1 Is a Potential Tumor Suppressor for Its Negative Association with Tumor Proliferation and Positive Association with Antitumor Immune Responses in Pan-Cancer

Background

Although numerous studies have shown that the expression and activation of TRPV1 have an important role in cancer development, a comprehensive exploration of associations between TRPV1 expression and tumor proliferation, microenvironment, and clinical outcomes in pan-cancer remains insufficient.

Methods

From The Cancer Genome Atlas (TCGA) program, we downloaded multiomics data of ten cancer cohorts and investigated the correlations between TRPV1 expression and immune signatures' enrichment, stromal content, genomic features, oncogenic signaling, and clinical features in these cancer cohorts and pan-cancer.

Results

Elevated expression of TRPV1 correlated with better clinical outcomes in pan-cancer and diverse cancer types. In multiple cancer types, TRPV1 expression correlated negatively with the expression of tumor proliferation marker genes (MKI67 and RACGAP1), proliferation scores, cell cycle scores, stemness scores, epithelial-mesenchymal transition scores, oncogenic pathways' enrichment, tumor immunosuppressive signals, intratumor heterogeneity, homologous recombination deficiency, tumor mutation burden, and stromal content. Moreover, TRPV1 expression was downregulated in late-stage versus early-stage tumors. In breast cancer, bladder cancer, and low-grade glioma, TRPV1 expression was more inferior in invasive than in noninvasive subtypes. Pathway analysis showed that the enrichment of cancer-associated pathways correlated inversely with TRPV1 expression levels.

Conclusion

TRPV1 upregulation correlates with decreased tumor proliferation, tumor driver gene expression, genomic instability, and tumor immunosuppressive signals in various cancers. Our results provide new understanding of the role of TRPV1 in both cancer biology and clinical practice.

Integrated Machine Learning and Single-Sample Gene Set Enrichment Analysis Identifies a TGF-Beta Signaling Pathway Derived Score in Headneck Squamous Cell Carcinoma

Background

The TGF-β signaling pathway is clinically predictive of pan-cancer. Nevertheless, its clinical prognosis and regulation of immune microenvironment (TME) characteristics as well as the prediction of immunotherapy efficacy need to be further elucidated in head and neck squamous cell carcinoma.

Method

At first, we summarized TGF-β related genes from previous published articles, used ssGSEA to establish the TGF-β risk score. Considering the complexity of its clinical application, we improved it with the LASSO-COX algorithm to construct the model. In addition, we explored the predictive efficacy of TGF-β risk score in the observation of TME phenotype and immunotherapy effect. Finally, the potency of TGF-β risk score in adjusting precise treatment of HNSC was evaluated.

Results

We systematically established TGF-β risk score with multi-level predictive ability. TGF-β risk score was employed to predict the tumor microenvironment status, which was negatively associated with NK cells but positively related to macrophages and fibroblasts. It reveals that patients with high TGF-β risk score predict “cold” TME status. In addition, higher risk scores indicate higher sensitivity to immunotherapy.

Conclusion

We first construct and validate TGF-β characteristics that can predict immune microenvironment phenotypes and immunotherapeutic effect in multiple datasets. Noteworthy, TGF-β risk score is helpful for individualized precise treatment of patients with the head and neck squamous cell carcinoma.

The interactions of CAP and LYN with the insulin signaling transducer CBL play an important role in polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a hormonal disorder characterized by hyperandrogenism, ovulatory dysfunction, and insulin resistance. Evidence suggests that aberrations in insulin signaling-associated pathways may underlie PCOS pathogenesis. Our aim was to investigate the molecular mechanisms underlying PCOS and associated insulin resistance using in silico analyses, in vitro cell models, and in vivo murine models.

METHODS

R-based bioinformatics analysis was performed on granulosa cell microarray data from three human cohorts: healthy control, PCOS patients without insulin resistance, and PCOS patients with insulin resistance. Transgenic human granulosa cell models were utilized for in vitro studies. Transgenic murine models of dehydroepiandrosterone (DHEA)-induced PCOS were utilized for in vivo studies.

RESULTS

Sorbin and SH3 Domain Containing 1 (SORBS1), the parent gene of the insulin receptor-associated Casitas B-lineage lymphoma protein (CBL)-associated protein (CAP), is a key downregulated gene in PCOS patients with insulin resistance. CAP binding to CBL reduced CBL^Y731 phosphorylation, CBL-phosphoinositide 3-kinase (PI3K) p85α interactivity, protein kinase B (Akt)^S473 phosphorylation, and NFκB-induced inflammatory marker expression but enhanced CRKII-mediated membrane GLUT4 translocation in granulosa cells. In contrast, the tyrosine kinase Lck/Yes-Related Novel Protein (LYN) is upregulated in PCOS patients with insulin resistance. LYN binding to CBL enhanced CBL^Y731 phosphorylation, CBL-PI3K p85α interactivity, Akt^S473 phosphorylation, and NFκB-induced inflammatory marker expression but did not impact membrane GLUT4 translocation. In PCOS mice, Cap overexpression, Cap transactivation by metformin, or enhancing Cbl-CrkII binding improved insulin sensitivity and ovarian dysfunction (i.e., estrous cycle disruption, cyst-like follicle formation, and sex hormone dysregulation). In contrast, Lyn knockdown, Lyn inhibition by PP2, or CBL-PI3K p85α blockade improved only ovarian dysfunction. Cbl^3YF phosphomutant overexpression (which enhances Cbl-CrkII binding but blocks Cbl-PI3K p85α binding) ameliorated both ovarian dysfunction and insulin resistance.

CONCLUSIONS

The interactions of CAP and LYN with CBL, and the resulting effects on CBL phosphorylation and activity, may play an important role in PCOS pathogenesis. Targeting these players may be a viable therapeutic strategy for PCOS.

Inhibitory role of proguanil on the growth of bladder cancer via enhancing EGFR degradation and inhibiting its downstream signaling pathway to induce autophagy

A major reason for the high mortality of patients with bladder cancer (BC) is that chemotherapy and surgery are only effective for very limited patients. Thus, developing novel treatment options becomes an urgent need for improving clinical outcomes and the quality of life for BC patients. Here, we demonstrated that proguanil significantly inhibited the growth of BC in vitro and in vivo. Importantly, our results indicated that the sensitivity of BC cells to proguanil is positively correlated with the expression of epidermal growth factor receptor (EGFR). Mechanistically, proguanil specifically targeted EGFR and promoted EGFR binding to Caveolin-1, enhanced its endocytosis in a Clathrin-independent manner, and then recruited c-Cbl to promote EGFR ubiquitination and degradation through the lysosomal pathway. Further studies suggested that proguanil induced autophagy by destabilizing EGFR and inhibiting its downstream signaling pathway. Thus, this study reveals the novel mechanism of proguanil on anticancer activity and implies the potential benefits of this drug in the treatment of BC.

Molecular Pathogenesis of Myeloproliferative Neoplasms: From Molecular Landscape to Therapeutic Implications

Despite distinct clinical entities, the myeloproliferative neoplasms (MPN) share morphological similarities, propensity to thrombotic events and leukemic evolution, and a complex molecular pathogenesis. Well-known driver mutations, JAK2, MPL and CALR, determining constitutive activation of JAK-STAT signaling pathway are the hallmark of MPN pathogenesis. Recent data in MPN patients identified the presence of co-occurrence somatic mutations associated with epigenetic regulation, messenger RNA splicing, transcriptional mechanism, signal transduction, and DNA repair mechanism. The integration of genetic information within clinical setting is already improving patient management in terms of disease monitoring and prognostic information on disease progression. Even the current therapeutic approaches are limited in disease-modifying activity, the expanding insight into the genetic basis of MPN poses novel candidates for targeted therapeutic approaches. This review aims to explore the molecular landscape of MPN, providing a comprehensive overview of the role of drive mutations and additional mutations, their impact on pathogenesis as well as their prognostic value, and how they may have future implications in therapeutic management.

Genomic and Epigenomic Landscape of Juvenile Myelomonocytic Leukemia

Simple Summary

Juvenile myelomonocytic leukemia (JMML) is a rare pediatric myelodysplastic/myeloproliferative neoplasm characterized by the constitutive activation of the RAS pathway. In spite of the recent progresses in the molecular characterization of JMML, this disease is still a clinical challenge due to its heterogeneity, difficult diagnosis, poor prognosis, and the lack of curative treatment options other than hematopoietic stem cell transplantation (HSCT). In this review, we will provide a detailed overview of the genetic and epigenetic alterations occurring in JMML, and discuss their clinical relevance in terms of disease prognosis and risk of relapse after HSCT. We will also present the most recent advances on novel preclinical and clinical therapeutic approaches directed against JMML molecular targets. Finally, we will outline future research perspectives to further explore the oncogenic mechanism driving JMML leukemogenesis and progression, with special attention to the application of single-cell next-generation sequencing technologies.

Abstract

Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/myeloproliferative neoplasm of early childhood. Most of JMML patients experience an aggressive clinical course of the disease and require hematopoietic stem cell transplantation, which is currently the only curative treatment. JMML is characterized by RAS signaling hyperactivation, which is mainly driven by mutations in one of five genes of the RAS pathway, including PTPN11, KRAS, NRAS, NF1, and CBL. These driving mutations define different disease subtypes with specific clinico-biological features. Secondary mutations affecting other genes inside and outside the RAS pathway contribute to JMML pathogenesis and are associated with a poorer prognosis. In addition to these genetic alterations, JMML commonly presents aberrant epigenetic profiles that strongly correlate with the clinical outcome of the patients. This observation led to the recent publication of an international JMML stratification consensus, which defines three JMML clinical groups based on DNA methylation status. Although the characterization of the genomic and epigenomic landscapes in JMML has significantly contributed to better understand the molecular mechanisms driving the disease, our knowledge on JMML origin, cell identity, and intratumor and interpatient heterogeneity is still scarce. The application of new single-cell sequencing technologies will be critical to address these questions in the future.

Role of CBL Mutations in Cancer and Non-Malignant Phenotype

Simple Summary

CBL mutations are progressively being described as involved in different clinical manifestations. Somatic CBL mutations can be found in different type of cancer. The clinical spectrum of germline mutations configures the so-called CBL syndrome, a cancer-predisposing condition that includes multisystemic involvement characterized by variable phenotypic expression and expressivity. In this review we provide an up-to-date review of the clinical manifestation of CBL mutations and of the molecular mechanisms in which CBL exerts its pathogenic role.

Abstract

CBL plays a key role in different cell pathways, mainly related to cancer onset and progression, hematopoietic development and T cell receptor regulation. Somatic CBL mutations have been reported in a variety of malignancies, ranging from acute myeloid leukemia to lung cancer. Growing evidence have defined the clinical spectrum of germline CBL mutations configuring the so-called CBL syndrome; a cancer-predisposing condition that also includes multisystemic involvement characterized by variable phenotypic expression and expressivity. This review provides a comprehensive overview of the molecular mechanisms in which CBL exerts its function and describes the clinical manifestation of CBL mutations in humans.

Increasing recognition and emerging therapies argue for dedicated clinical trials in chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). Median overall survival of this aggressive myeloid malignancy is only 2-3 years, with a 15-30% risk of acute leukemic transformation. The paucity of clinical trials specifically designed for CMML has made therapeutic management of CMML patients challenging. As a result, treatment paradigms for CMML patients are largely borrowed from MDS and MPN. The standard of care still relies on hydroxyurea, hypomethylating agents (HMA), and allogeneic stem cell transplantation, this latter option remaining the only potentially curative therapy. To date, approved drugs for CMML treatment are HMA, including azacitidine, decitabine, and more recently the oral combination of decitabine and cedazuridine. However, HMA treatment does not meaningfully alter the natural course of this disease. New treatment approaches for improving CMML-associated cytopenias or targeting the CMML malignant clone are emerging. More than 25 therapeutic agents are currently being evaluated in phase 1 or phase 2 clinical trials for CMML and other myeloid malignancies, often in combination with a HMA backbone. Several novel agents, such as sotatercept, ruxolitinib, lenzilumab, and tagraxofusp have shown promising clinical efficacy in CMML. Current evidence supports the idea that effective treatment in CMML will likely require combination therapy targeting multiple pathways, which emphasizes the need for additional new therapeutic options. This review focuses on recent therapeutic advances and innovative treatment strategies in CMML, including global and molecularly targeted approaches. We also discuss what may help to make progress in the design of rationally derived and disease-modifying therapies for CMML.

Targeting Akt in cancer for precision therapy

Biomarkers-guided precision therapeutics has revolutionized the clinical development and administration of molecular-targeted anticancer agents. Tailored precision cancer therapy exhibits better response rate compared to unselective treatment. Protein kinases have critical roles in cell signaling, metabolism, proliferation, survival and migration. Aberrant activation of protein kinases is critical for tumor growth and progression. Hence, protein kinases are key targets for molecular targeted cancer therapy. The serine/threonine kinase Akt is frequently activated in various types of cancer. Activation of Akt promotes tumor progression and drug resistance. Since the first Akt inhibitor was reported in 2000, many Akt inhibitors have been developed and evaluated in either early or late stage of clinical trials, which take advantage of liquid biopsy and genomic or molecular profiling to realize personalized cancer therapy. Two inhibitors, capivasertib and ipatasertib, are being tested in phase III clinical trials for cancer therapy. Here, we highlight recent progress of Akt signaling pathway, review the up-to-date data from clinical studies of Akt inhibitors and discuss the potential biomarkers that may help personalized treatment of cancer with Akt inhibitors. In addition, we also discuss how Akt may confer the vulnerability of cancer cells to some kinds of anticancer agents.