The Expressions and Mechanisms of Sarcomeric Proteins in Cancers

Mechanotransduction and Skeletal Muscle Atrophy: The Interplay Between Focal Adhesions and Oxidative Stress

Mechanical unloading leads to profound musculoskeletal degeneration, muscle wasting, and weakness. Understanding the specific signaling pathways involved is essential for uncovering effective interventions. This review provides new perspectives on mechanotransduction pathways, focusing on the critical roles of focal adhesions (FAs) and oxidative stress in skeletal muscle atrophy under mechanical unloading. As pivotal mechanosensors, FAs integrate mechanical and biochemical signals to sustain muscle structural integrity. When disrupted, these complexes impair force transmission, activating proteolytic pathways (e.g., ubiquitin-proteasome system) that accelerate atrophy. Oxidative stress, driven by mitochondrial dysfunction and NADPH oxidase-2 (NOX2) hyperactivation, exacerbates muscle degeneration through excessive reactive oxygen species (ROS) production, impaired repair mechanisms, and dysregulated redox signaling. The interplay between FA dysfunction and oxidative stress underscores the complexity of muscle atrophy pathogenesis: FA destabilization heightens oxidative damage, while ROS overproduction further disrupts FA integrity, creating a self-amplifying vicious cycle. Therapeutic strategies, such as NOX2 inhibitors, mitochondrial-targeted antioxidants, and FAK-activating compounds, promise to mitigate muscle atrophy by preserving mechanotransduction signaling and restoring redox balance. By elucidating these pathways, this review advances the understanding of muscle degeneration during unloading and identifies promising synergistic therapeutic targets, emphasizing the need for combinatorial approaches to disrupt the FA-ROS feedback loop.

Multi-omics insights into the molecular signature and prognosis of hypopharyngeal squamous cell carcinoma

Approximately two-thirds of hypopharyngeal squamous cell carcinoma (HPSCC) cases are diagnosed at advanced stages, with the worst prognosis among head and neck squamous cell carcinomas (HNSCCs). Identifying biomarkers for high-risk patients requiring aggressive treatment is crucial. We present mutational, transcriptomic, and proteomic studies of 103 Chinese HPSCC patients and observe a higher prevalence and poorer prognosis in males. Estrogen response pathways are up-regulated, and proteins phosphorylated by protein kinase C (PKC) and cyclin-dependent kinases (CDKs) are aberrantly regulated in HPSCC. We identify aberrant copy number regions including SOX2(3q26.33), FGFR(8p11.23), CCND1(11q13.3), CDKN2A/2B(9p21.3), and MYC(8q24.21). Human papillomavirus (HPV) status combined with highly mutated genes, such as SYNE1 in HPV(-) and MUC4 in HPV(+) patients, were assessed as prognosis markers. A predictive model involving clinical factors and expression of six genes was established and cross-site validated. These findings open new opportunities for stratifying high-risk patients and molecular targets for personalized therapeutic strategies.

Colonic Tubular Adenoma with Clear Cell Change: Case Report with Whole-Exome Sequencing and Updated Review of the Literature

INTRODUCTION

Colorectal tubular adenomas displaying clear cell change are rare entities, with unknown clinical relevance, prognosis, immunohistochemical, and molecular features.

CASE PRESENTATION

Hereby we report a case of a 43-year-old female patient with a rectosigmoid polyp. Histologically, conventional dysplasia was visible with scattered areas displaying clear cell change. Whole-exome sequencing (WES) was carried out and revealed high tumour mutation burden and 7 pathogenic mutations, including TP53, APC, FGFR4, EHBP1, IL4R, TYR, and ACTN3.

CONCLUSION

Clear cell change may only be present in less than 0.1% of adenomas. Aetiology is not well understood; additionally, few authors suggest autolysis or fixation problems. Our WES resulted in newly found pathogenic mutations, and high mutation burden, proving the lesion's neoplastic origin. Hitherto, neither special stainings nor immunohistochemical markers proved to be useful in the diagnostic process. From a differential diagnostic perspective, enteroblastic differentiation, primary and secondary clear cell adenocarcinoma has to be excluded.

FOLFIRINOX chemotherapy modulates the peripheral immune landscape in pancreatic cancer: Implications for combination therapies and early response prediction

BACKGROUND

FOLFIRINOX chemotherapy has improved outcomes for pancreatic cancer patients, but poor long-term survival outcomes and high toxicity remain challenges. This study investigates the impact of FOLFIRINOX on plasma proteins and peripheral immune cells to guide immune-based combination therapies and, ideally, to identify a potential biomarker to predict early disease progression during FOLFIRINOX.

METHODS

Blood samples were collected from 86 pancreatic cancer patients before and two weeks after the first FOLFIRINOX cycle and subjected to comprehensive immune cell and proteome profiling. Principal Component Analysis and Linear Mixed Effect Regression models were used for data analysis. FOLFIRINOX efficacy was radiologically evaluated after the fourth cycle.

RESULTS

One cycle of FOLFIRINOX diminished tumour-cell-related pathways and enhanced pathways related to immune activation, illustrated by an increase in pro-inflammatory IL-18, IL-15, and TNFRSF4. Similarly, FOLFIRINOX promoted the activation of CD4 + and CD8 + T cells, the proliferation of NK(T), and the activation of antigen-presenting cells. Furthermore, high pre-treatment levels of VEGFA and PRDX3 and an elevation in FCRL3 levels after one cycle predicted early progression under FOLFIRINOX. Finally, patients with progressive disease exhibited high levels of inhibitory markers on B cells and CD8 + T cells, while responding patients exhibited high levels of activation markers on CD4 + and CD8 + T cell subsets.

CONCLUSION

FOLFIRINOX has immunomodulatory effects, providing a foundation for clinical trials exploring immune-based combination therapies that harness the immune system to treat pancreatic cancer. In addition, several plasma proteins hold potential as circulating predictive biomarkers for early prediction of FOLFIRINOX response in patients with pancreatic cancer.

CHRNA1 and its correlated-myogenesis/cell cycle genes are prognosis-related markers of metastatic melanoma

Nicotinic acetylcholine receptors (CHRNs) expression and their critical role in various types of cancer have been reported. However, it is still unclear which CHRNs and their associated genes play essential roles in metastasis in melanoma patients. Here, we performed bioinformatics analyses on publicly available bulk RNA sequencing (RNA-seq) data of patients with melanoma to identify the CHRNs highly expressed in metastatic melanoma. We found that CHRNA1 was highly expressed in metastatic melanoma samples compared to primary melanoma samples and was strongly associated with CHRNB1 and CHRNG. These muscle-type CHRNs (CHRNA1, CHRNB1, and CHRNG) were correlated with the ZEB1 and Rho/ROCK pathway-related genes in metastatic melanoma samples. Pairwise correlations and enrichment analyses revealed that CHRNA1 was significantly associated with myogenesis/muscle contraction and cell cycle genes. Kaplan-Meier curves illustrated the involvement of CHRNA1, four of its correlated genes (DES, FLNC, CDK1, and CDC20), and the myogenesis gene signature in the prognosis of melanoma patients. Following the bulk RNA-seq analysis, single-cell RNA-seq (scRNA-seq) analysis showed that the CHRNA1-expressing melanoma cells are primarily metastatic and had high expression levels of CHRNB1, CHRNG, and myogenesis/cell cycle-related genes. Our bioinformatics analyses of the bulk RNA-seq and scRNA-seq data of patients with melanoma revealed that CHRNA1 and its correlated myogenesis/cell-related cycle genes are critical prognosis-related markers of metastatic melanoma.

Leucine zipper protein 2 serves as a prognostic biomarker for prostate cancer correlating with immune infiltration and epigenetic regulation

Background

We sought to determine whether leucine zipper protein 2 (LUZP2) could benefit men with prostate cancer (PCa) undergoing radical radiotherapy (RT) or prostatectomy (RP).

Methods

Analysis was done on differentiating expression, clinical prognosis, co-expressed genes, immune infiltration, and epigenetic changes. All of our analyses were done using the R software (version 3.6.3) and the appropriate packages.

Results

In terms of PCa, tumor samples expressed LUZP2 more than normal samples did. In the TCGA database and GSE116918, we found that LUZP2 was the only independent risk factor for PCa. The shared enriched pathways for patients undergoing RP or RT were cell-cell adhesion, regulation of filopodium assembly, and extracellular matrix containing collagen. With the exception of TNFRSF14, we discovered that LUZP2 was negatively correlated with 21 immune checkpoints in PCa patients receiving RT. We found a significant inverse relationship between LUZP2 expression and the tumor immune environment, which included B cells, CD4+ T cells, neutrophils, macrophages, dendritic cells, stromal score, immune score, and estimate score, in patients receiving RP or RT. Additionally, tumor purity was positively correlated with LUZP2. We found that the drug bortezomib may be susceptible to the LUZP2. DNA methylation was significantly associated with the mRNA expression of LUZP2 in PCa patients from the TCGA database, and LUZP2 methylation was positively correlated with immune cells. The proliferative activity of various PCa cells, which correlated to different stages of this disease, was also found to be significantly reduced by LUZP2 reduction, according to the results of our experimental work.

Conclusions

We proposed a relatively comprehensive understanding of the roles of LUZP2 on PCa from the fresh perspective of senescence.

Targeted massively parallel sequencing of candidate regions on chromosome 22q predisposing to multiple schwannomas: An analysis of 51 individuals in a single-center experience

Constitutional LZTR1 or SMARCB1 pathogenic variants (PVs) have been found in ∼86% of familial and ∼40% of sporadic schwannomatosis cases. Hence, we performed massively parallel sequencing of the entire LZTR1, SMARCB1, and NF2 genomic loci in 35 individuals with schwannomas negative for constitutional first-hit PVs in the LZTR1/SMARCB1/NF2 coding sequences; however, with 22q deletion and/or a different NF2 PV in each tumor, including six cases with only one tumor available. Furthermore, we verified whether any other LZTR1/SMARCB1/NF2 (likely) PVs could be found in 16 cases carrying a SMARCB1 constitutional variant in the 3'-untranslated region (3'-UTR) c.*17C>T, c.*70C>T, or c.*82C>T. As no additional variants were found, functional studies were performed to clarify the effect of these 3'-UTR variants on the transcript. The 3'-UTR variants c.*17C>T and c.*82C>T showed pathogenicity by negatively affecting the SMARCB1 transcript level. Two novel deep intronic SMARCB1 variants, c.500+883T>G and c.500+887G>A, resulting in out-of-frame missplicing of intron 4, were identified in two unrelated individuals. Further resequencing of the entire repeat-masked genomics sequences of chromosome 22q in individuals negative for PVs in the SMARCB1/LZTR1/NF2 coding- and noncoding regions revealed five potential schwannomatosis-predisposing candidate genes, that is, MYO18B, NEFH, SGSM1, SGSM3, and SBF1, pending further verification.