Upregulated Histone Deacetylase 6 Associates with Malignant Progression of Melanoma and Predicts the Prognosis of Patients

Neutrophil-to-lymphocyte ratio dynamics: prognostic value and potential for surveilling glioblastoma recurrence

PURPOSE

Glioblastoma (GBM) is a challenging malignancy with a poor prognosis. While the neutrophil-to-lymphocyte ratio (NLR) is reported to correlate with the prognosis, the significance of changes in the NLR and its prognostic value in GBM remain unclear. This study aims to evaluate changes in the NLR and its predictive value for GBM prognosis and recurrence.

METHODS

The cohort included 69 newly-diagnosed GBM patients undergoing a standard treatment protocol. NLR was assessed at multiple time points. The dynamic change in NLR (dNLR), defined as the NLR at the point of interest (post-CCRT or post-Stupp) divided by the preoperative NLR, also was assessed. Univariate and multivariate COX regression analyses were conducted to assess the association between the NLR, dNLR and overall survival (OS) and progression-free survival (PFS).

RESULTS

Univariate analysis revealed that age at diagnosis ≥ 70 (p = 0.019) and post-Stupp dNLR ≥ 1.3 (p = 0.006) were significantly associated with shorter OS. Significant correlations were found between pre-operative KPS ≥ 60 (p = 0.017), gross total resection (p = 0.042), post-Stupp dNLR ≥ 1.3 (p = 0.043) and PFS. Multivariate analysis showed age at diagnosis ≥ 70, pre-operative KPS ≥ 60, post-Stupp NLR ≥ 5 and dNLR ≥ 1.3 were significantly associated with a shorter OS. Significant correlation was found between pre-operative KPS ≥ 60 and PFS.

CONCLUSION

This study revealed that post-Stupp NLR ≥ 5 and dNLR ≥ 1.3 correlated significantly with a worse glioblastoma prognosis in OS, and dNLR might be more reliable. These two parameters are potentially surveilling markers for glioblastoma recurrence, however further studies are warranted.

WT161, a selective HDAC6 inhibitor, decreases growth, enhances chemosensitivity, promotes apoptosis, and suppresses motility of melanoma cells

PURPOSE

Histone deacetylase 6 (HDAC6) plays a critical role in tumorigenesis and tumor progression, contributing to proliferation, chemoresistance, and cell motility by regulating microtubule architecture. Despite its upregulation in melanoma tissues and cell lines, the specific biological roles of HDAC6 in melanoma are not well understood. This study aims to explore the functional effects and underlying mechanisms of WT161, a selective HDAC6 inhibitor, in melanoma cell lines.

METHODS

Cell proliferation was assessed using both 2D and 3D cell culture systems, including MTT assays, spheroid growth analyses, and colony formation assays. The interaction between WT161 and the chemotherapeutic agents temozolomide (TMZ) or dacarbazine (DTIC) was evaluated using the Chou-Talalay method. Apoptotic cell death was analyzed through flow cytometry, while migration, adhesion, and invasion assays were conducted to evaluate the motility capacities of melanoma cells. Western blot assays quantified α-tubulin acetylation (Lys40), PARP cleavage, and protein levels of β-catenin and E-cadherin.

RESULTS

WT161 significantly reduced cell growth in both 2D and 3D cultures, decreased clonogenic capacity, and showed synergistic interactions with TMZ and DTIC. The inhibitor also induced apoptotic cell death and enhanced TMZ-induced apoptosis. Additionally, WT161 reduced cell migration and invasion while increasing cell adhesion. These effects were linked to changes in β-catenin and E-cadherin levels, depending on the specific cell type evaluated.

CONCLUSION

Our study underscores the pivotal role of HDAC6 in melanoma progression, establishing it as a promising therapeutic target. We provide the first comprehensive evidence of WT161's anti-melanoma effects, setting the stage for further research into HDAC6 inhibitors as a potential strategy for melanoma treatment.

Upgrading Melanoma Treatment: Promising Immunotherapies Combinations in the Preclinical Mouse Model

Background:

Melanoma, known for its high metastatic potential, does not respond well to existing treatments in advanced stages. As a solution, immunotherapy-based treatments, including anti-PD-1/L1 and anti-CTLA-4, have been developed and evaluated in preclinical mouse models to overcome resistance. Although these treatments display the potential to suppress tumor growth, there remains a crucial requirement for a thorough assessment of long-term efficacy in preventing metastasis or recurrence and improving survival rates.

Methods:

From 2016 onwards, a thorough examination of combined immunotherapies for the treatment of cutaneous melanoma in preclinical mouse models was conducted. The search was conducted using MeSH Terms algorithms in PubMed®, resulting in the identification of forty-five studies that met the rigorous inclusion criteria for screening.

Results:

The C57 mouse model bearing B16-melanoma has been widely utilized to assess the efficacy of immunotherapies. The combination of therapies has demonstrated a synergistic impact, leading to potent antitumor activity. One extensively studied method for establishing metastatic models involves the intravenous administration of malignant cells, with several combined therapies under investigation. The primary focus of evaluation has been on combined immunotherapies utilizing PD- 1/L1 and CTLA-4 blockade, although alternative immunotherapies not involving PD-1/L1 and CTLA-4 blockade have also been identified. Additionally, the review provides detailed treatment regimens for each combined approach.

Conclusion:

The identification of techniques for generating simulated models of metastatic melanoma and investigating various therapeutic combinations will greatly aid in evaluating the overall systemic efficacy of immunotherapy. This will be especially valuable for conducting short-term preclinical experiments that have the potential for clinical studies.

Histone deacetylase 6: at the interface of cancer and neurodegeneration

With the recognition in the early 1960s that histones can be post-translationally modified, the list of different post-translational modifications of histones and their biological consequences has continued to expand. In addition, the idea of the 'histone code' hypothesis, later introduced by David Allis and colleagues, further broaden the horizon of chromatin biology. Currently, there is a wealth of knowledge about the transition between the active and the repressive state of chromatin, and modifications of histones remains at the center of chromatin biology. Histone deacetylases (HDACs) in particular are of great importance for the therapeutic success of cancer treatment. Focusing primarily on HDAC6, herein we have briefly highlighted its unique involvement in cancer and also apparently in neurodegeneration.

Prognostic biomarker CCR6 and its correlation with immune infiltration in cutaneous melanoma

Background

Cutaneous melanoma (CM) is an aggressive type of skin cancer. Even after standard treatment, the recurrence and malignant progression of CM were almost inevitable. The overall survival (OS) of patients with CM varied widely, making it critical for prognostic prediction. Based on the correlation between CCR6 and melanoma incidence, we aimed to investigate the prognostic role of CCR6 and its relationship with immune infiltration in CM.

Methods

We obtained RNA sequencing data from The Cancer Genome Atlas (TCGA) to analyze the CM expression. Functional enrichment analyses, immune infiltration analyses, immune checkpoint analyses, and clinicopathology analyses were performed. Univariate and multivariate Cox regression analyses were used to identify independent prognostic factors. A nomogram model had been developed. Kaplan-Meier survival analysis and log-rank test were used to estimate the relationship between OS and CCR6 expression.

Results

CCR6 was significantly upregulated in CM. Functional enrichment analyses revealed that CCR6 was correlated with immune response. Most immune cells and immune checkpoints were positively correlated with CCR6 expression. Kaplan-Meier analyses showed that high CCR6 expression was associated with a good outcome in CM and its subtypes. Cox regression showed that CCR6 was an independent prognostic factor in patients with CM (HR = 0.550, 95% CI = 0.332-0.912, p<0.05).

Conclusions

CCR6 is considered to be a new prognostic biomarker for patients with CM, and our study provides a potential therapeutic target for CM treatment.

New insights into epigenetic regulation of resistance to PD-1/PD-L1 blockade cancer immunotherapy: mechanisms and therapeutic opportunities

Programmed cell death protein 1(PD-1) is a type of immune-inhibitory checkpoint protein, which delivers inhibitory signals to cytotoxic T cells by binding to the programmed death ligand-1 (PD-L1) displayed on the surface of cancer cells. Antibodies blocking PD-1/PD-L1 interaction have been extensively used in treatment of human malignancies and have achieved promising outcomes in recent years. However, gradual development of resistance to PD-1/PD-L1 blockade has decreased the effectiveness of this immunotherapy in cancer patients. The underlying epigenetic mechanisms need to be elucidated for application of novel strategies overcoming this immunotherapy resistance. Epigenetic aberrations contribute to cancerogenesis by promoting different hallmarks of cancer. Moreover, these alterations may lead to therapy resistance, thereby leading to poor prognosis. Recently, the epigenetic regulatory drugs have been shown to decrease the resistance to PD-1/PD-L1 inhibitors in certain cancer patients. Inhibitors of the non-coding RNAs, DNA methyltransferases, and histone deacetylases combined with PD-1/PD-L1 inhibitors have shown considerable therapeutic efficacy against carcinomas as well as blood cancers. Importantly, DNA methylation-mediated epigenetic silencing can inhibit antigen processing and presentation, which promotes cancerogenesis and aggravates resistance to PD-1/PD-L1 blockade immunotherapy. These observations altogether suggest that the combination of the epigenetic regulatory drugs with PD-1/PD-L1 inhibitors may present potential solution to the resistance caused by monotherapy of PD-1/PD-L1 immunotherapy.

Histone Modification on Parathyroid Tumors: A Review of Epigenetics

Parathyroid tumors are very prevalent conditions among endocrine tumors, being the second most common behind thyroid tumors. Secondary hyperplasia can occur beyond benign and malignant neoplasia in parathyroid glands. Adenomas are the leading cause of hyperparathyroidism, while carcinomas represent less than 1% of the cases. Tumor suppressor gene mutations such as MEN1 and CDC73 were demonstrated to be involved in tumor development in both familiar and sporadic types; however, the epigenetic features of the parathyroid tumors are still a little-explored subject. We present a review of epigenetic mechanisms related to parathyroid tumors, emphasizing advances in histone modification and its perspective of becoming a promising area in parathyroid tumor research.

Histone deacetylase 6-mediated downregulation of TMEM100 expedites the development and progression of non-small cell lung cancer

The significance of epigenetic modulation, involving acetylation, methylation, as well as ubiquitination has been indicated in the regulation of gene expression and tumor progression. Here, we elucidated the role of histone deacetylase 6 (HDAC6) in regulating epithelial-mesenchymal transition (EMT)-mediated metastasis via mRNA in non-small cell lung cancer (NSCLC). Three microarrays associated with lung cancer metastasis or recurrence, GSE23361, GSE7880 and GSE162102, were downloaded from the GEO database. Transmembrane protein 100 (TMEM100) was revealed to be the only one mRNA that was significantly downregulated in three microarrays. TMEM100, poorly expressed in lung cancer tissues, was associated with poor prognosis of lung cancer patients. Moreover, TMEM100 transcription was regulated by HDAC6 which repressed TMEM100 expression by deacetylation modification on the TMEM100 promoter. Knockdown of HDAC6 or overexpression of TMEM100 in NSCLC cells significantly inhibited TGF-β1-induced EMT and metastasis and suppressed the activation of Wnt/β-catenin signaling pathway. Altogether, our study highlights HDAC6 as a lung cancer metastasis supporter through the suppression of TMEM100 and the induction of Wnt/β-catenin signaling pathway.

Interrogating Epigenome toward Personalized Approach in Cutaneous Melanoma

Epigenetic alterations have emerged as essential contributors in the pathogenesis of various human diseases, including cutaneous melanoma (CM). Unlike genetic changes, epigenetic modifications are highly dynamic and reversible and thus easy to regulate. Here, we present a comprehensive review of the latest research findings on the role of genetic and epigenetic alterations in CM initiation and development. We believe that a better understanding of how aberrant DNA methylation and histone modifications, along with other molecular processes, affect the genesis and clinical behavior of CM can provide the clinical management of this disease a wide range of diagnostic and prognostic biomarkers, as well as potential therapeutic targets that can be used to prevent or abrogate drug resistance. We will also approach the modalities by which these epigenetic alterations can be used to customize the therapeutic algorithms in CM, the current status of epi-therapies, and the preliminary results of epigenetic and traditional combinatorial pharmacological approaches in this fatal disease.