The Class I HDAC Inhibitor Valproic Acid Strongly Potentiates Gemcitabine Efficacy in Pancreatic Cancer by Immune System Activation

Synergistic therapeutics: Co-targeting histone deacetylases and ribonucleotide reductase for enhanced cancer treatment

The development of cancer is influenced by several variables, including altered protein expression, and signaling pathways. Cancers are inherently heterogeneous and exhibit genetic and epigenetic aberrations; therefore, developing therapies that act on numerous biological targets is encouraged. To achieve this, two approaches are employed: combination therapy and dual/multiple targeting chemotherapeutics. Two enzymes, histone deacetylases (HDACs) and ribonucleotide reductase (RR), are crucial for several biological functions, including replication and repair of DNA, division of cells, transcription of genes, etc. However, it has been noted that different cancers exhibit abnormal functions of these enzymes. Potent inhibitors for each of these proteins have been extensively researched. Many medications based on these inhibitors have been successfully food and drug administration (FDA) approved, and the majority are undergoing various stages of clinical testing. This review discusses various studies of HDAC and RR inhibitors in combination therapy and dual-targeting chemotherapeutics.

Genetic Signature of Human Pancreatic Cancer and Personalized Targeting

Pancreatic cancer is a highly lethal disease with a 5-year survival rate of around 11-12%. Surgery, being the treatment of choice, is only possible in 20% of symptomatic patients. The main reason is that when it becomes symptomatic, IT IS the tumor is usually locally advanced and/or has metastasized to distant organs; thus, early diagnosis is infrequent. The lack of specific early symptoms is an important cause of late diagnosis. Unfortunately, diagnostic tumor markers become positive at a late stage, and there is a lack of early-stage markers. Surgical and non-surgical cases are treated with neoadjuvant and/or adjuvant chemotherapy, and the results are usually poor. However, personalized targeted therapy directed against tumor drivers may improve this situation. Until recently, many pancreatic tumor driver genes/proteins were considered untargetable. Chemical and physical characteristics of mutated KRAS are a formidable challenge to overcome. This situation is slowly changing. For the first time, there are candidate drugs that can target the main driver gene of pancreatic cancer: KRAS. Indeed, KRAS inhibition has been clinically achieved in lung cancer and, at the pre-clinical level, in pancreatic cancer as well. This will probably change the very poor outlook for this disease. This paper reviews the genetic characteristics of sporadic and hereditary predisposition to pancreatic cancer and the possibilities of a personalized treatment according to the genetic signature.

Emerging therapeutic strategies in cancer therapy by HDAC inhibition as the chemotherapeutic potent and epigenetic regulator

In developing new cancer medications, attention has been focused on novel epigenetic medicines called histone deacetylase (HDAC) inhibitors. Our understanding of cancer behavior is being advanced by research on epigenetics, which also supplies new targets for improving the effectiveness of cancer therapy. Most recently published patents emphasize HDAC selective drugs and multitarget HDAC inhibitors. Though significant progress has been made in emerging HDAC selective antagonists, it is urgently necessary to find new HDAC blockers with novel zinc-binding analogues to avoid the undesirable pharmacological characteristics of hydroxamic acid. HDAC antagonists have lately been explored as a novel approach to treating various diseases, including cancer. The complicated terrain of HDAC inhibitor development is summarized in this article, starting with a discussion of the many HDAC isotypes and their involvement in cancer biology, followed by a discussion of the mechanisms of action of HDAC inhibitors, their current level of development, effect of miRNA, and their combination with immunotherapeutic.

Epigenetic regulation in epilepsy: A novel mechanism and therapeutic strategy for epilepsy

Epilepsy is a common neurological disorder characterized by recurrent seizures with excessive and abnormal neuronal discharges. Epileptogenesis is usually involved in neuropathological processes such as ion channel dysfunction, neuronal injury, inflammatory response, synaptic plasticity, gliocyte proliferation and mossy fiber sprouting, currently the pathogenesis of epilepsy is not yet completely understood. A growing body of studies have shown that epigenetic regulation, such as histone modifications, DNA methylation, noncoding RNAs (ncRNAs), N6-methyladenosine (m6A) and restrictive element-1 silencing transcription factor/neuron-restrictive silencing factor (REST/NRSF) are also involved in epilepsy. Through epigenetic studies, we found that the synaptic dysfunction, nerve damage, cognitive dysfunction and brain development abnormalities are affected by epigenetic regulation of epilepsy-related genes in patients with epilepsy. However, the functional roles of epigenetics in pathogenesis and treatment of epilepsy are still to be explored. Therefore, profiling the array of genes that are epigenetically dysregulated in epileptogenesis is likely to advance our understanding of the mechanisms underlying the pathophysiology of epilepsy and may for the amelioration of these serious human conditions provide novel insight into therapeutic strategies and diagnostic biomarkers for epilepsy to improve serious human condition.

HDAC inhibition delays photoreceptor loss in Pde6b mutant mice of retinitis pigmentosa: insights from scRNA-seq and CUT&Tag

Purpose

This research aimed to ascertain the neuroprotective effect of histone deacetylase (HDAC) inhibition on retinal photoreceptors in Pde6brd1 mice, a model of retinitis pigmentosa (RP).

Methods

Single-cell RNA-sequencing (scRNA-seq) explored HDAC and poly (ADP-ribose) polymerase (PARP)-related gene expression in both Pde6b-mutant rd1 and wild-type (WT) mice. The CUT&Tag method was employed to examine the functions of HDAC in rd1 mice. Organotypic retinal explant cultures from WT and rd1 mice were exposed to the HDAC inhibitor SAHA (suberoylanilide hydroxamic acid) postnatally, from day 5 to day 11. The terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assay was applied to quantify the percentage of photoreceptor loss in the outer nuclear layer (ONL). HDAC activity was confirmed to be inhibited by SAHA through an HDAC activity assay. Moreover, the study evaluated PARP activity, a key driver of the initial response to DNA damage during photoreceptor degeneration, following HDAC inhibition.

Results

The scRNA-seq revealed that diverse roles of HDAC and PARP isoforms in photoreceptor cell death. HDAC-related genes appeared to regulate cell death and primary immunodeficiency. Alterations in HDAC activity were consistent with the TUNEL-positive cells in the ONL at different time points. Notably, SAHA significantly postponed photoreceptor loss and decreased HDAC and PARP activity, thereby implicating both in the same degenerative pathway.

Conclusions

This study highlights that the interaction between HDAC inhibition and PARP can delay photoreceptor cell death, proposing a promising therapeutic approach for RP.

Exploring Precise Medication Strategies for OSCC Based on Single-Cell Transcriptome Analysis from a Dynamic Perspective

Simple Summary

At the time of diagnosis, most oral squamous cell carcinoma (OSCC) patients are in the middle or advanced stages, and advanced patients usually have poor prognosis after traditional therapy. One of the primary causes has been demonstrated to be heterogeneity. However, most of the current studies on tumor heterogeneity are static, while the development of cancer is dynamic. Thus, understanding the tumor development process from a dynamic perspective is deeply necessary. Here, we combined static and dynamic analysis based on single-cell RNA-Seq data to comprehensively dissect the complex heterogeneity and evolutionary process of OSCC. We pioneered the concept of pseudo-time score, which is closely related to patient’s prognosis. Finally, we identified candidate drugs and proposed precision medication strategies to control OSCC in two respects: treatment and blocking. Our findings offer new insights for clinical practice and could help improve the treatment of advanced OSCC.

Abstract

At present, most patients with oral squamous cell carcinoma (OSCC) are in the middle or advanced stages at the time of diagnosis. Advanced OSCC patients have a poor prognosis after traditional therapy, and the complex heterogeneity of OSCC has been proven to be one of the main reasons. Single-cell sequencing technology provides a powerful tool for dissecting the heterogeneity of cancer. However, most of the current studies at the single-cell level are static, while the development of cancer is a dynamic process. Thus, understanding the development of cancer from a dynamic perspective and formulating corresponding therapeutic measures for achieving precise treatment are highly necessary, and this is also one of the main study directions in the field of oncology. In this study, we combined the static and dynamic analysis methods based on single-cell RNA-Seq data to comprehensively dissect the complex heterogeneity and evolutionary process of OSCC. Subsequently, for clinical practice, we revealed the association between cancer heterogeneity and the prognosis of patients. More importantly, we pioneered the concept of pseudo-time score of patients, and we quantified the levels of heterogeneity based on the dynamic development process to evaluate the relationship between the score and the survival status at the same stage, finding that it is closely related to the prognostic status. The pseudo-time score of patients could not only reflect the tumor status of patients but also be used as an indicator of the effects of drugs on the patients so that the medication strategy can be adjusted on time. Finally, we identified candidate drugs and proposed precision medication strategies to control the condition of OSCC in two respects: treatment and blocking.

The impact of Omicron pandemic and COVID-19 vaccination on the pancreatic adenocarcinoma patients

Background

The coronavirus disease 2019 (COVID-19) pandemic resulted in enormous medical and economic burden worldwide during the past 3 years. The vaccination was deemed the effective option to prevent the severe symptoms, and especially recommended among cancer patients. Shanghai experienced the first lockdown during the recent Omicron pandemic since 2019. How patients with pancreatic adenocarcinoma (PAC) suffered from the pandemic and how vaccination influenced their oncological outcomes were unexplored yet.

Method

The retrospective study was carried out in a high-volume referral center including 1157 consecutively enrolled patients with PAC experiencing the COVID-19 pandemic. The primary outcome was the overall survival (OS).

Results

Limited postoperative patients (9.21%) received the vaccination. The lockdown in Shanghai (April to May, 2022) was not observed impacting the survival prognoses of patients with PAC. Though vaccination was not significantly associated with OS itself (adjusted hazard ratio (aHR): 2.032 [0.940-4.391], p = 0.071), it was discovered to synergistically improve the chemotherapy effect in the multivariate analyses (interaction p = 0.023).

Conclusion

The vaccination itself did not influence the survival prognoses of patients with PAC. A potential positive interaction was observed between chemotherapy and vaccination despite the limited follow-up time. The postoperative patients should consider the vaccination more. The patients with PAC did not suffer worse prognostic outcomes from the strict sanitary policy during the wave of COVID-19 pandemic in Shanghai.

Immunomodulatory antitumor effect of interferon‑beta combined with gemcitabine in pancreatic cancer

Resistance to gemcitabine is common and critically limits its therapeutic efficacy in patients with pancreatic cancer. Interferon‑beta (IFN‑β) induces numerous antitumor effects and synergizes with gemcitabine treatment. The immunomodulatory effects of this treatment regimen have not yet been described. In the present study, the antitumor effect of IFN‑β combined with gemcitabine was investigated in immune competent mice. Mouse KPC3 cells were used in all experiments. Treatment effects were determined with cell proliferation assay. Reverse transcription‑quantitative PCR was used to measure gene expression. For in vivo experiments, cells were subcutaneously injected in immune competent mice. For immune profiling, NanoString analysis was performed on tumor samples of treated and untreated mice. Baseline expression of Ifnar‑1 and Ifnar‑2c in KPC3 cells was 1.42±0.16 and 1.50±0.17, respectively. IC50 value of IFN‑β on cell growth was high (>1,000 IU/ml). IFN‑β pre‑treatment increased the in vitro response to gemcitabine (1.3‑fold decrease in EC50; P<0.001). In vivo, tumor size was not statistically significant smaller in mice treated with IFN‑β plus gemcitabine (707±92 mm3 vs. 1,239±338 mm3 in vehicle‑treated mice; P=0.16). IFN‑β alone upregulated expression of numerous immune‑related genes. This effect was less pronounced when combined with gemcitabine. For the first time, to the best of our knowledge, the immunomodulatory effects of IFN‑β, alone and combined with gemcitabine, in pancreatic cancer were reported. Prognostic markers for predicting effective responses to IFN‑β therapy are urgently needed.