Thyroid collision tumors (TCTs) are rare thyroid malignancies characterized by the coexistence of distinct tumor types. We investigated the histopathology, immunohistochemistry, and gene mutations to comprehensively characterize the heterogeneity of TCTs.

DNA methylation is a key epigenetic modification catalyzed by DNA methyltransferases (DNMTs) and predominantly occurs at cytosine-phosphate-guanine (CpG) islands, which are often located in gene promoter regions. Hypermethylation of CpG islands within gene promoters can silence tumor suppressor gene expression, thereby disrupting normal cellular functions, including maintenance of genomic stability and regulation of cell growth, and contributing to tumor initiation and progression. In contrast, global hypomethylation may promote genomic instability and oncogene activation. This review discusses the molecular mechanisms underlying DNA methylation and evaluates its functional and clinical significance in colorectal and gastric cancers, with emphasis on its potential application as a noninvasive biomarker for diagnosis.

Neuroblastoma (NB) is the most common extracranial solid tumor among pediatric cancers and accounts for approximately 15% of childhood cancer-related deaths. Neurotrophic receptor tyrosine kinases (NTRKs) are genes that play critical roles in the development and function of the nervous system. Therefore, elucidating the role of NTRKs in NB is important for both understanding basic biological mechanisms and developing novel therapeutic approaches. Specifically, NTRK fusions are being investigated as potential biomarkers and therapeutic targets for targeted therapy strategies. The tumor-agnostic TRK inhibitors larotrectinib and entrectinib are used to treat advanced or metastatic solid tumors with NTRK gene fusions. Accordingly, this study aimed to investigate the clinical significance of NTRK1, NTRK2, and NTRK3 point mutations, gene fusions, and protein expression, and to assess the effectiveness of these in guiding targeted therapy decisions in NB.

Single-stranded DNA gaps (ssDNA gaps) have emerged as a potential indicator of therapeutic response in cancer. Accumulation of ssDNA gaps is associated with increased sensitivity of cancer cells to genotoxic therapies like PARP inhibitors (PARPi) and cisplatin chemotherapy. However, efficient repair or suppression of ssDNA gap formation is associated with therapy resistance and treatment failure. Therefore, understanding how ssDNA gaps form and are repaired can help identify biomarkers that can guide new treatment strategies to overcome resistance. In this review, we discuss different sources of ssDNA gap formation and the repair mechanisms that have been characterized to date. We bring together current knowledge on how these gaps are processed and what their ultimate fate may be. Finally, we discuss how established drugs like PARPi, hydroxyurea, and platinum compounds, induce and/or exploit ssDNA gaps. Throughout this review, we highlight ssDNA gaps as a potential therapeutic vulnerability that can be used to advance personalized cancer therapy.

The recommended first-line therapy for BRAF V600E mutant non-small cell lung cancer (NSCLC) is a combination of dabrafenib and trametinib. Most patients respond to the initial therapy, but some show resistance in the early stages. Additionally, immune checkpoint inhibitors (ICIs) are often used after resistance develops; however, the benefits of ICIs in patients with BRAF V600E mutant NSCLC remain unclear.

Objective. Multiple endocrine neoplasia type 1 (MEN1) is a very rare genetic disorder characterized by an autosomal dominant inheritance. We aim through this case series to delineate the wide spectrum of its clinical features. Methods. In the present study, we report the clinical and genetic findings of four siblings affected by this disorder. DNA was extracted from patients' blood leukocytes using a phenol-chloroform method and assessed for purity with a NanoDrop spectrophotometer. Ten exons of the MEN1 gene were amplified by PCR, verified by gel electrophoresis, and sequenced using Big Dye Terminator chemistry followed by capillary electrophoresis. The sequences were than analyzed with CHROMAS and compared to reference sequences. As for the variant, interpretation and pathogenicity were assessed using Ensembl, ClinVar, dbSNP, gnomAD, Alamut Visual, and VARSOME. Results. We highlight the wide range of phenotypes encompassing primary hyperparathyroidism, macroprolactinoma, lipomas, papillary thyroid carcinoma, ectopic thyroid, multinodular goiter, and bilateral adrenal nodules observed in this family contrasting with the same pathogenic frameshift mutation. We also pinpoint to a second mutation detected in two of the siblings while discussing its pathogenicity. Finally, we provide an overview of the clinical manifestations of MEN1 and its genetic background. Conclusion. This research sets the stage to further investigate the molecular mechanisms underlying the novel nonsense mutation. Additionally, it incites other research to explore the frequency of this mutation in other populations and finally to conduct functional studies.

Objective. The BAG cochaperone 1 (BAG1) binds to oncogene BCL2 and markedly enhances its anti-apoptotic effects. This cochaperone represents a link between growth factor receptors and anti-apoptotic mechanisms mediated by endoplasmic reticulum stress. BAG1 interacts with the glucocorticoid receptor and modulates its transcription activity. As a cochaperone for several HSP70 proteins, it participates in control of protein folding. The present study aims to investigate the regulation of the BAG1 mRNA expression in U87MG glioblastoma cells by hypoxia and glucose or glutamine deprivation, depending on the inhibition of ERN1 (endoplasmic reticulum to nucleus signaling 1) with the intent to reveal the role of ERN1 signaling in the regulation of this gene expression and function in oncogenesis. Methods. The U87MG glioblastoma cells (transfected by an empty vector; control) and cells with inhibited ERN1 endoribonuclease and protein kinase (dnERN1) or only ERN1 endoribonuclease (dnrERN1) were used. Silencing of ERN1 and XBP1 mRNAs for suppression of ERN1 function was also used. A hypoxic condition was created by dimethyloxalylglycine (4 h). DMEM medium without glucose or glutamine was used for glucose and glutamine deprivation (16 h). The expression level of the BAG1 mRNA was studied by real-time qPCR and normalized to the beta-actin mRNA. Results. Inhibition of the endoribonuclease activity of ERN1 significantly decreased BAG1 mRNA expression. However, a lesser suppression of this mRNA expression was observed in dnERN1 cells (with inhibited ERN1 endoribonuclease and protein kinase) indicating the involvement of protein kinase in controlling BAG1 expression. The silencing of ERN1 and XBP1 mRNAs also reduced the expression of BAG1 mRNA demonstrating the involvement of XBP1s in this regulation. The expression of the BAG1 gene was resistant to glutamine deprivation and upregulated in response to glucose deprivation in control glioblastoma cells. However, the inhibition of ERN1 increased the sensitivity of BAG1 gene expression to both glucose and glutamine deprivation. Furthermore, the expression of the BAG1 gene was increased under hypoxia in control U87MG cells; however, a greater induction was observed in dnERN1 cells. Conclusion. The results of this study demonstrated that ERN1 inhibition reduces BAG1 mRNA expression through the endoribonuclease activity of ERN1 and that protein kinase activity counteracts endoribonuclease in regulating the expression of BAG1 mRNA. Moreover, ERN1 inhibition also enhances the sensitivity of BAG1 mRNA expression to nutrient supply and hypoxia resulting in reduced resistance of glioblastoma cells.

Objective. Phosphoenolpyruvate carboxykinase (PCK) catalyzes the conversion of oxaloacetate to phosphoenolpyruvate and regulates pyruvate metabolism and gluconeogenesis in response to glucocorticoid and insulin stimuli. Mitochondrial isoform of this enzyme (PCK2) is overexpressed in glioblastoma cells and participates in metabolic reprogramming and cell proliferation. This study aims to examine the impact of ERN1 (endoplasmic reticulum to nucleus signaling 1) inhibition on PCK2 expression and sensitivity to glucose and glutamine deprivation to determine the role of ERN1 signaling in the regulating its expression in glioblastoma cells. Methods. The glioblastoma cell line U87MG and two genetically modified variants of these cells were used. These were glioblastoma cell sublines with suppressed endoribonuclease and protein kinase activities of ERN1 (dnERN1) or only ERN1 endoribonuclease (dnrERN1), and control cells transfected with an empty vector. The suppression of ERN1 function by silencing of ERN1 and XBP1 mRNAs was also used. Hypoxia was generated using the HIF1A prolyl hydroxylase inhibitor dimethyloxalylglycine. For glucose and glutamine deprivation, DMEM medium without glucose or glutamine was used. The expression level of the PCK2 mRNA was analyzed by real-time qPCR and normalized to the beta-actin mRNA. Results. It has been demonstrated that PCK2 mRNA expression is significantly decreased in dnERN1 glioblastoma cells. Similar suppression of this mRNA expression was also observed in cells with only the endoribonuclease activity of ERN1 inhibited, indicating that this enzymatic activity is involved in the regulation of PCK2 expression. The silencing of ERN1 and XBP1 mRNAs also induced similar changes in PCK2 mRNA expression, possibly mediated by XBP1s. The expression of PCK2 was enhanced under glutamine deprivation in control glioblastoma cells, but inhibition of ERN1 activity strongly increased this effect. Upregulated PCK2 expression was also observed in control glioblastoma cells under glucose deprivation. However, the inhibition of ERN1 activity strongly increased the sensitivity of this gene expression to glucose deprivation. Furthermore, PCK2 mRNA expression was resistant to hypoxic conditions in cells with native ERN1. At the same time, in glioblastoma cells with inhibited ERN1 activity, a strong induction of PCK2 expression was observed. Conclusion. The results of this study demonstrated that ERN1 inhibition reduces PCK2 mRNA expression through the ERN1 endoribonuclease activity. This mRNA expression is upregulated under glutamine and glucose deprivation. Moreover, ERN1 inhibition strongly enhanced the sensitivity of PCK2 mRNA expression to glucose and glutamine deprivation as well as to hypoxia.

Mixed-phenotype acute leukemias (MPALs) are a rare and aggressive group of leukemias, accounting for approximately 2%-5% of all leukemia cases. MPAL is characterized by the expression of markers from more than one hematopoietic lineage, either myeloid and lymphoid, which can be identified through flow cytometry immunophenotyping. This study aims to describe the clinicopathological, immunophenotypic, and cytogenetic features of a cohort of 27 patients diagnosed with MPAL at our institution.

Ewing family of tumors (EFT) encompass a group of small blue round cell tumors, including Ewing sarcoma (ES) and EWSR1-negative undifferentiated small round cell sarcoma. The distinction between the EFTs is essential from a clinical perspective due to prognostic and therapeutic differences and is substantiated by the advent of molecular testing in the modern era. In this study, we tried to characterize EFTs by using fluorescent in situ hybridization (FISH) and reverse transcriptase polymerase chain reaction (RT-PCR).

Head and neck cancer (HNC), predominantly head and neck squamous cell carcinoma (HNSCC), poses a significant health burden globally. Intensity-modulated radiation therapy (IMRT) has improved outcomes in HNC; however, radiation-induced toxicities, particularly oral mucositis and dermatitis, remain critical concerns. Genetic variations, such as single-nucleotide polymorphisms (SNPs) in the TGF-β1 gene (-509C>T, rs1800469), may modulate these toxicities and impact treatment response.

The emergence of immune checkpoint inhibitors (ICIs) has transformed the treatment landscape of metastatic melanoma. However, despite its success, reliable biomarkers for predicting primary resistance are not available in clinical practice. This study seeks to identify predictors of primary resistance based on novel gene expression signatures. The transcriptomic profile of the tumor microenvironment was analyzed using tissue samples from 46 metastatic cutaneous melanoma patients collected prior to the initiation of ICIs therapy. A primary resistance predictive model was trained with the Discovery FFPE RNA-seq subcohort and validated using an independent external cohort of 54 samples. Additionally, liquid biopsy samples from peripheral blood mononuclear cells were analyzed in 8 patients using single-cell RNA sequencing (scRNA-seq) and in 46 patients using flow cytometry. We identified an 82-gene transcriptomic signature composed of tumor- and immune-related genes that stratifies metastatic cutaneous melanoma patients based on primary resistance to ICIs, with key markers including CXCL13, WDR63, MZB1, FDCSP, IGKC and GRIK3. This signature achieved an AUC of 0.814. Immune deconvolution guided by scRNA-seq revealed four immune cell subsets (Plasma cells, Pre-B cells, memory CD4⁺ T cells, and naive CD4⁺ T cells) as prognostic indicators of resistance. We propose a transcriptomic biomarker signature that accurately predicts primary resistance to ICIs in metastatic cutaneous melanoma. Through the integration of immune deconvolution with circulating immune cell profiles, we derived an ImmuneSignature linked to patient survival. By combining these approaches, we provide a framework for enhancing the prediction of immunotherapy outcomes and offer a novel strategy for identifying therapeutic targets to overcome resistance.

Uterine leiomyosarcoma (uLMS) is a rare but aggressive malignant mesenchymal tumor, accounting for 2-5% of uterine malignancies. Because its symptoms and imaging features often resemble those of benign uterine leiomyoma (LM), accurate preoperative diagnosis remain difficult. This review summarizes recent advances in liquid biopsy for uLMS and explores its potential for early detection, molecular characterization, and treatment monitoring.

Acromegaly is a rare endocrine disorder characterized by the excessive production of growth hormone (GH) in adulthood, usually (95 percent of the time) due to a benign tumor in the pituitary gland (PitNET). Although GNAS variants are the most prevalent cause of sporadic somatotroph tumors, these can rarely occur in a familial setting (5 percent). Hereditary GH-secreting PitNETs can manifest as isolated tumors, such as in familial isolated pituitary adenoma (FIPA) including cases with AIP variants or GPR101 microduplications, (X- linked acrogigantism) or can be part of syndromes like multiple endocrine neoplasia type 1 or type 4, McCune-Albright syndrome, Carney complex or phaeochromocytoma/paraganglioma-pituitary adenoma association. Identifying genetic defects allows an early detection and prompt intervention, essential for preventing complications and improving the quality of life in affected individuals, as well as finding affected relatives before the clinical manifestations of the disease.

Combination immunotherapies such as atezolizumab plus bevacizumab (Atez/Bev) and durvalumab plus tremelimumab (Dur/Tre) improve outcomes in advanced hepatocellular carcinoma (HCC), yet systemic immune mechanisms underlying response remain incompletely defined.

Chimeric antigen receptor (CAR) T-cell therapy has demonstrated safety and modest efficacy against diffuse midline gliomas (DMGs), a highly aggressive pediatric brain tumor. However, mechanisms of CAR T-cell resistance in DMG settings remain unknown.

This study explores the locations and distribution of mutations in the exons of the TP53 gene in pulmonary large cell neuroendocrine carcinomas (LCNEC) and the corresponding expression of p53 as well as the Ki-67 proliferation index. Real-world data from routine diagnostics were collected retrospectively from 149 consecutive cases of pulmonary LCNEC. They included next-generation sequencing (NGS) of the TP53 gene along with evaluation of p53 and Ki-67 expression with immunohistochemistry (IHC). Abnormal p53 expression was defined as strong positive nuclear reaction in more than 20% of the tumor cells or complete absence of immunostaining in tumor cells. Both p53 expression and Ki-67 proliferation index correlated with TP53 mutations. In addition, a statistically significant increase in Ki-67 expression was found for cases with abnormal staining of p53 compared to samples with normal staining. We found that IHC staining for p53 can identify TP53 mutations in pulmonary LCNEC with an overall concordance of 76.6%. Moreover, both pathological patterns of p53 immunostaining and NGS-detected TP53 mutations were associated with higher Ki-67 proliferation indices.

Triple-negative breast cancer (TNBC) is known for its more aggressive clinical behavior, poor prognosis, and distinctive patterns of metastasis. Neoadjuvant chemotherapy (NAC) can influence both tumor cells and the tumor microenvironment. Emerging evidence highlights the critical role of actin cytoskeletal dynamics in cancer progression.

Deficient DNA mismatch repair (dMMR) and microsatellite instability-high (MSI-H) status, which sensitizes tumors to immune checkpoint inhibitors (ICIs), is three times more common with upper tract urothelial carcinoma (UTUC) than with bladder cancer. However, data on ICI efficacy against dMMR/MSI-H advanced UTUC remain limited.

Advanced esophageal squamous cell carcinoma (ESCC) has a poor prognosis, and current treatments provide limited survival benefits. This study aimed to identify prognostic biomarkers and therapeutic targets by genomic profiling of advanced ESCC using circulating tumor DNA (ctDNA).