Enhanced Immunotherapy with LHRH-R Targeted Lytic Peptide in Ovarian Cancer

Peptides for diagnosis and treatment of ovarian cancer

Ovarian cancer is the most deadly gynecologic malignancy, and its incidence is gradually increasing. Despite improvements after treatment, the results are unsatisfactory and survival rates are relatively low. Therefore, early diagnosis and effective treatment remain two major challenges. Peptides have received significant attention in the search for new diagnostic and therapeutic approaches. Radiolabeled peptides specifically bind to cancer cell surface receptors for diagnostic purposes, while differential peptides in bodily fluids can also be used as new diagnostic markers. In terms of treatment, peptides can exert cytotoxic effects directly or act as ligands for targeted drug delivery. Peptide-based vaccines are an effective approach for tumor immunotherapy and have achieved clinical benefit. In addition, several advantages of peptides, such as specific targeting, low immunogenicity, ease of synthesis and high biosafety, make peptides attractive alternative tools for the diagnosis and treatment of cancer, particularly ovarian cancer. In this review, we focus on the recent research progress regarding peptides in the diagnosis and treatment of ovarian cancer, and their potential applications in the clinical setting.

Peptides as Pharmacological Carriers to the Brain: Promises, Shortcomings and Challenges

Central nervous system (CNS) diseases are among the most difficult to treat, mainly because the vast majority of the drugs fail to cross the blood-brain barrier (BBB) or to reach the brain at concentrations adequate to exert a pharmacological activity. The obstacle posed by the BBB has led to the in-depth study of strategies allowing the brain delivery of CNS-active drugs. Among the most promising strategies is the use of peptides addressed to the BBB. Peptides are versatile molecules that can be used to decorate nanoparticles or can be conjugated to drugs, with either a stable link or as pro-drugs. They have been used to deliver to the brain both small molecules and proteins, with applications in diverse therapeutic areas such as brain cancers, neurodegenerative diseases and imaging. Peptides can be generally classified as receptor-targeted, recognizing membrane proteins expressed by the BBB microvessels (e.g., Angiopep2, CDX, and iRGD), "cell-penetrating peptides" (CPPs; e.g. TAT_47-57, SynB1/3, and Penetratin), undergoing transcytosis through unspecific mechanisms, or those exploiting a mixed approach. The advantages of peptides have been extensively pointed out, but so far few studies have focused on the potential negative aspects. Indeed, despite having a generally good safety profile, some peptide conjugates may display toxicological characteristics distinct from those of the peptide itself, causing for instance antigenicity, cardiovascular alterations or hemolysis. Other shortcomings are the often brief lifetime in vivo, caused by the presence of peptidases, the vulnerability to endosomal/lysosomal degradation, and the frequently still insufficient attainable increase of brain drug levels, which remain below the therapeutically useful concentrations. The aim of this review is to analyze not only the successful and promising aspects of the use of peptides in brain targeting but also the problems posed by this strategy for drug delivery.

Effect of CRISPR/Cas9-Edited PD-1/PD-L1 on Tumor Immunity and Immunotherapy

Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease9 (CRISPR/Cas9) gene editing technology implements precise programming of the human genome through RNA guidance. At present, it has been widely used in the construction of animal tumor models, the study of drug resistance regulation mechanisms, epigenetic control and innovation in cancer treatment. Tumor immunotherapy restores the normal antitumor immune response by restarting and maintaining the tumor-immune cycle. CRISPR/Cas9 technology has occupied a central position in further optimizing anti-programmed cell death 1(PD-1) tumor immunotherapy. In this review, we summarize the recent progress in exploring the regulatory mechanism of tumor immune PD-1 and programmed death ligand 1(PD-L1) based on CRISPR/Cas9 technology and its clinical application in different cancer types. In addition, CRISPR genome-wide screening identifies new drug targets and biomarkers to identify potentially sensitive populations for anti-PD-1/PD-L1 therapy and maximize antitumor effects. Finally, the strong potential and challenges of CRISPR/Cas9 for future clinical applications are discussed.

CACNA1C is a prognostic predictor for patients with ovarian cancer

BACKGROUND

CACNA1C, as a type of voltage-dependent calcium ion transmembrane channel, played regulatory roles in the development and progress of multiple tumors. This study was aimed to analyze the roles of CACNA1C in ovarian cancer (OC) of overall survival (OS) and to explore its relationships with immunity.

METHODS

Single gene mRNA sequencing data and corresponding clinical information were obtained from The Cancer Genome Atlas Database (TCGA) and the International Cancer Genome Consortium (ICGC) datasets. Gene set enrichment analysis (GSEA) was used to identify CACNA1C-related signal pathways. Univariate and multivariate Cox regression analyses were applied to evaluate independent prognostic factors. Besides, associations between CACNA1C and immunity were also explored.

RESULTS

CACNA1C had a lower expression in OC tumor tissues than in normal tissues (P < 0.001), with significant OS (P = 0.013) and a low diagnostic efficiency. We further validated the expression levels of CACNA1C in OC by means of the ICGC dataset (P = 0.01), qRT-PCR results (P < 0.001) and the HPA database. Univariate and multivariate Cox hazard regression analyses indicated that CACNA1C could be an independent risk factor of OS for OC patients (both P < 0.001). Five significant CACNA1C-related signaling pathways were identified by means of GSEA. As for genetic alteration analysis, altered CACNA1C groups were significantly associated with OS (P = 0.0169), progression-free survival (P = 0.0404), disease-free survival (P = 0.0417) and disease-specific survival (P = 9.280e-3), compared with unaltered groups in OC. Besides, CACNA1C was dramatically associated with microsatellite instability (MSI) and immunity.

CONCLUSIONS

Our results shed light on that CACNA1C could be a prognostic predictor of OS in OC and it was closely related to immunity.

Therapeutic Peptides Targeting PPI in Clinical Development: Overview, Mechanism of Action and Perspectives

Targeting protein-protein interactions (PPIs) has been recently recognized as an emerging therapeutic approach for several diseases. Up today, more than half a million PPI dysregulations have been found to be involved in pathological events. The dynamic nature of these processes and the involvement of large protein surfaces discouraged anyway the scientific community in considering them promising therapeutic targets. More recently peptide drugs received renewed attention since drug discovery has offered a broad range of structural diverse sequences, moving from traditionally endogenous peptides to sequences possessing improved pharmaceutical profiles. About 70 peptides are currently on the marked but several others are in clinical development. In this review we want to report the update on these novel APIs, focusing our attention on the molecules in clinical development, representing the direct consequence of the drug discovery process of the last 10 years. The comprehensive collection will be classified in function of the structural characteristics (native, analogous, heterologous) and on the basis of the therapeutic targets. The mechanism of interference on PPI will also be reported to offer useful information for novel peptide design.

Targeting Cancer Heterogeneity with Immune Responses Driven by Oncolytic Peptides

Accumulating preclinical and clinical evidence indicates that high degrees of heterogeneity among malignant cells constitute a considerable obstacle to the success of cancer therapy. This calls for the development of approaches that operate - or enable established treatments to operate - despite such intratumoral heterogeneity (ITH). In this context, oncolytic peptides stand out as promising therapeutic tools based on their ability to drive immunogenic cell death associated with robust anticancer immune responses independently of ITH. We review the main molecular and immunological pathways engaged by oncolytic peptides, and discuss potential approaches to combine these agents with modern immunotherapeutics in support of superior tumor-targeting immunity and efficacy in patients with cancer.