Re-survey of 16 Japanese patients with advanced-stage hereditary motor sensory neuropathy with proximal dominant involvement (HMSN-P): Painful muscle cramps for early diagnosis

Hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) is an intractable neurological disease with autosomal dominant inheritance, four-limb weakness, sensory impairment, and a slowly progressive course. HMSN-P patients develop four-limb paralysis at the advanced-stage, as in amyotrophic lateral sclerosis (ALS). There is a natural 20- to 30-year course from initial painful muscle cramps and four-limb paralysis to respiratory dysfunction. A delay in the diagnosis of HMSN-P occurs due to the 20- to 30-year span from the initial symptom(s) to typical quadriplegia. Its early diagnosis is important, but the involvement of painful muscle cramps as an early symptom has not been clear. Following our earlier survey, we conducted a re-survey focusing on painful muscle cramps, assistive-device use, and hope for specific therapies in 16 Japanese patients with advanced-stage HMSN-P. Fifteen patients presented painful muscle cramps as the initial symptom, and muscle cramps in the lower abdomen including the flank were described by 10 of the patients. The presence of painful muscle cramps including those in the abdominal region may be a clue for the early diagnosis of HMSN-P. Painful abdominal cramps have not described in related diseases, e.g., ALS, spinal muscular atrophy, and Charcot-Marie-Tooth disease. Recent patient-welfare improvements and advances in assistive devices including robot-suit assistive limbs are delaying the terminal state of HMSN-P. Regarding specific therapies for HMSN-P, many patients choose both nucleic acid medicine and the application of induced pluripotent stem cells as a specific therapy for HMSN-P.

Acerola exosome-like nanovesicles to systemically deliver nucleic acid medicine via oral administration

Extracellular vesicles derived from mammalian cells could be useful carriers for drug delivery systems (DDSs); however, with regard to clinical application, there are several issues to be overcome. Acerola (Malpighia emarginata DC.) is a popular health food. In this study, the feasibility of orally administered nucleic acid drug delivery by acerola exosome-like nanoparticles (AELNs) was examined. AELNs were recovered from acerola juice using an affinity column instead of ultracentrifugation. MicroRNA (miRNA) was sufficiently encapsulated in AELNs by 30-min incubation on ice and was protected against RNase, strong acid, and base treatments. The administration of an AELN/miRNA mixture in cells achieved downregulation of the miRNA’s target gene, and this mixture showed cytoplasmic localization. AELNs orally delivered small RNA to the digestive system in vivo. The target gene-suppressing effect in the small intestine and liver peaked 1 day after administration, indicating potential for use as an oral DDS for nucleic acid in the digestive system.

Short-Chain Guide RNA for Site-Directed A-to-I RNA Editing

Site-directed RNA editing is a promising genetic modification technology for therapeutic and pharmaceutical applications. We previously constructed adenosine deaminases acting on RNA (ADAR)-guiding RNAs (AD-gRNAs) that direct A-to-I RNA editing activity of native human ADAR2 into a programmable target site. In this study, we developed the short-chain AD-gRNA (shAD-gRNA) as a potential basic framework for practical RNA-editing oligonucleotides. Based on knowledge of previous AD-gRNA, shAD-gRNAs were designed to have the shortest possible sequence for the induction of editing activity. In vitro, compared to the original AD-gRNA, the shAD-gRNAs showed similar or superior editing induction activity, depending on the target RNA sequence, and had lower off-target editing activity around the target site, which is predicted to be a hotspot for off-target editing. Moreover, shAD-gRNAs achieved target RNA editing with both exogenous and endogenous human ADARs in cultured cells. Our results present shAD-gRNA as a short basic framework that would be applicable to further development for practical RNA-editing oligonucleotides.

ARL4C is associated with initiation and progression of lung adenocarcinoma and represents a therapeutic target

Lung adenocarcinoma is the most common histological type of lung cancer and is classified into adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA). Atypical adenomatous hyperplasia (AAH) lesions are possible precursors to adenocarcinoma. However, the mechanism underlying the stepwise continuum of lung adenocarcinoma is unclear. In this study, the involvement of ADP‐ribosylation factor (ARF)‐like (ARL) 4C (ARL4C), a member of the small GTP‐binding protein family, in the progression of lung adenocarcinoma and the possibility of ARL4C as a molecular target for lung cancer therapy were explored. ARL4C was frequently expressed in AAH and ARL4C expression in immortalized human small airway epithelial cells promoted cell proliferation and suppressed cell death. In addition, ARL4C was expressed with increased frequency in AIS, MIA and IA in a stage‐dependent manner, and the expression was correlated with histologic grade, fluorine‐18 fluorodeoxyglucose uptake and poor prognosis. An anti–sense oligonucleotide (ASO) against ARL4C (ARL4C ASO‐1316) inhibited RAS‐related C3 botulinum toxin substrate activity and nuclear import of Yes‐associated protein and transcriptional coactivator with PDZ‐binding motif, and suppressed in vitro proliferation and migration of lung cancer cells with KRAS or epidermal growth factor receptor (EGFR) mutations. In addition, transbronchial administration of ARL4C ASO‐1316 suppressed orthotopic tumor formation induced by these cancer cells. Thus, ARL4C is involved in the initiation of the premalignant stage and is associated with the stepwise continuum of lung adenocarcinoma. ARL4C ASO‐1316 would be useful for lung adenocarcinoma patients expressing ARL4C regardless of the KRAS or EGFR mutation.

Development and Clinical Trials of Nucleic Acid Medicines for Pancreatic Cancer Treatment

Approximately 30% of pancreatic cancer patients harbor targetable mutations. However, there has been no therapy targeting these molecules clinically. Nucleic acid medicines show high specificity and can target RNAs. Nucleic acid medicine is expected to be the next-generation treatment next to small molecules and antibodies. There are several kinds of nucleic acid drugs, including antisense oligonucleotides, small interfering RNAs, microRNAs, aptamers, decoys, and CpG oligodeoxynucleotides. In this review, we provide an update on current research of nucleic acid-based therapies. Despite the challenging obstacles, we hope that nucleic acid drugs will have a significant impact on the treatment of pancreatic cancer. The combination of genetic diagnosis using next generation sequencing and targeted therapy may provide effective precision medicine for pancreatic cancer patients.

NEK2 Is an Effective Target for Cancer Therapy With Potential to Induce Regression of Multiple Human Malignancies

Cancer is characterized by uncontrolled cell proliferation due to the aberrant activity of various proteins. Cell cycle-related proteins are thought to be important in several functions, such as proliferation, invasion and drug resistance in human malignancies. Never in mitosis gene A-related kinase 2 (NEK2) is a cell cycle-related protein. NEK2 is highly expressed in various tumor types and cancer cell lines. NEK2 expression is correlated with rapid relapse and poor outcome in multiple cancer types. Several researchers have demonstrated that NEK2 inhibition results in anticancer effects against many types of cancers, both in vitro and in vivo. Recent research strongly indicates the advantages of NEK2-targeted therapy for cancer. This review focuses on the current understanding of NEK2 in cancer and the rationale of a xenograft cancer model for cancer treatment. A possible therapeutic strategy, such as inhibitor and nucleic acid medicine targeting of NEK2, is also discussed.

Silencing PRDM14 expression by an innovative RNAi therapy inhibits stemness, tumorigenicity, and metastasis of breast cancer

PR domain zinc finger protein 14 (PRDM14) maintains stemness in embryonic stem cells via epigenetic mechanisms. Although PRDM14 is elevated in several cancers, it is unclear if and how PRDM14 confers stem cell-like properties and epigenetic changes to cancer cells. Here, we examined the phenotypic characteristics and epigenetic and gene expression profiles of cancer cells that differentially express PRDM14, and assessed the potential of PRDM14-targeted cancer therapy. PRDM14 expression was markedly increased in many different cancer types and correlated with poor survival of breast cancer patients. PRDM14 conferred stem cell-like phenotypes to cancer cells and regulated the expression of genes involved in cancer stemness, metastasis, and chemoresistance. PRDM14 also reduced the methylation of proto-oncogene and stemness gene promoters and PRDM14-binding regions were primarily occupied by histone H3 Lys-4 trimethylation (H3K4me3), both of which are positively correlated with gene expression. Moreover, strong PRDM14 binding sites coincided with promoters containing both H3K4me3 and H3K27me3 histone marks. Using calcium phosphate hybrid micelles as an RNAi delivery system, silencing of PRDM14 expression by chimera RNAi reduced tumor size and metastasis in vivo without causing adverse effects. Conditional loss of PRDM14 function also improved survival of MMTV-Wnt-1 transgenic mice, a spontaneous model of murine breast cancer. Our findings suggest that PRDM14 inhibition may be an effective and novel therapy for cancer stem cells.