The parathyroid hormone regulates skin tumour susceptibility in mice

Targeting PAK1 is effective against cutaneous squamous cell carcinoma in a syngenic mouse model

By taking advantage of forward genetic analysis in mice, we have demonstrated that Pak1 plays a crucial role during DMBA/TPA skin carcinogenesis. Although Pak1 has been considered to promote cancer development, its overall function remains poorly understood. To clarify the functional significance of Pak1 in detail, we sought to evaluate the possible effect of an allosteric inhibitor against PAK1 (NVS-PAK1-1) on a syngeneic mouse model. To this end, we established two cell lines, 9AS1 and 19AS1, derived from DMBA/TPA-induced squamous cell carcinoma (SCC) that engrafted in FVB mice. Based on our present results, NVS-PAK1-1 treatment significantly inhibited the growth of tumors derived from 9AS1 and 19AS1 cells in vitro and in vivo. RNA-sequencing analysis on the engrafted tumors indicates that NVS-PAK1-1 markedly potentiates the epidermal cell differentiation and enhances the immune response in the engrafted tumors. Consistent with these observations, we found an expansion of Pan-keratin-positive regions and potentially elevated infiltration of CD8-positive immune cells in NVS-PAK1-1-treated tumors as examined by immunohistochemical analyses. Together, our present findings strongly suggest that PAK1 is tightly linked to the development of SCC, and that its inhibition is a promising therapeutic strategy against SCC.

AST-120 improved uremic pruritus by lowering indoxyl sulfate and inflammatory cytokines in hemodialysis patients

BACKGROUND AND HYPOTHESIS

Pruritus is a common and distressing symptom that affects patients with chronic kidney disease. The concentration of protein bounded uremic toxin was associated with the uremic pruritus. The aim is to assess the efficacy of AST-120 for uremic pruritus in hemodialysis patients.

MATERIALS AND METHODS

The participants were enrolled and then divided into the AST-120 treatment group and control group with a ratio of 2:1. All participants underwent pre-observation screenings two weeks before the study with three visits. In the treatment phase (week 1 to week 4), the treatment group added 6g/day of AST-120 along with routine anti-pruritic treatment. Visual analog scale (VAS) and biochemical parameters were measured.

RESULTS

The VAS score began to be lower in the AST-120 treatment group after the 5th visiting (p < 0.05). The reduction in indoxyl sulfate (IS) at 5th week along with TNF-alpha. The reduction ratio of indoxyl sulfate correlated with reduction of parathyroid hormone.

CONCLUSION

This study has demonstrated that the four-week treatment of AST-120 decreased the severity of uremic pruritus in patients with ESRD. The concentration of IS and TNF-alpha decreased in the AST-120 treatment group. The reduction of iPTH correlated with the reduction of IS in the AST-120 treatment.

Correlation of Carotid Artery Intima-Media Thickness with Calcium and Phosphorus Metabolism, Parathyroid Hormone, Microinflammatory State, and Cardiovascular Disease

The internal thickness of the carotid artery is the vertical distance between the intima of the carotid artery and the middle mold. Its normal thickness is less than 1 mm. It can be used to judge the degree of arteriosclerosis. Under normal circumstances, the change of the internal thickness of the carotid artery is caused by cardiovascular disease. The purpose of this article is to study the relationship between the thickness of the carotid artery and the metabolism of calcium and phosphorus, parathyroid hormone, microinflammatory state, and cardiovascular disease. This article uses ultrasound measurement to measure the IMT of ESRD patients and carotid arteries with normal renal function. The analysis includes blood pressure, blood phosphorus, blood calcium, blood creatinine, blood urea nitrogen, blood sugar, glycosylated hemoglobin, blood lipids, parathyroid hormone, and C reaction. The correlation between clinical indicators includes protein and carotid IMT in ESRD patients which can be used in designing a diagnostic plan for patients through correlation research. The results showed that the carotid artery IMT of ESRD nondialysis patients was 13% thicker than that of those with normal renal function, and it was significantly positively correlated with age, blood pressure, blood phosphorus, glycosylated hemoglobin, and C-reactive protein. The correlation ratio with calcium and phosphorus was about 0.1.

Functional polymorphism in Pak1-3'UTR alters skin tumor susceptibility by alternative polyadenylation

We identified a functional single nucleotide polymorphism (SNP) in the 3' untranslated region (UTR) of p21-activated kinase 1 (Pak1) that is responsible for the Skin tumor modifier of MSM 1a locus. Candidate SNPs in the 3'UTR of Pak1 from resistance strain MSM/Ms were introduced into susceptible strain FVB/N using CRISPR/Cas9. DMBA/TPA skin carcinogenesis experiments revealed an SNP (Pak1-3'UTR-6^C>T: rs31627325) that strongly suppressed skin tumors. Furthermore, Muscleblind-Like Splicing Regulator 1 bound more strongly to FVB-allele (6^C/C) and regulated the transcript length in the 3'UTR of Pak1 and tumorigenesis via polyadenylation. Therefore, the alternative polyadenylation of Pak1 is cis-regulated by rs31627325.

A wild-derived inbred mouse strain, MSM/Ms, provides insights into novel skin tumor susceptibility genes

Cancer is one of the most catastrophic human genetic diseases. Experimental animal cancer models are essential for gaining insights into the complex interactions of different cells and genes in tumor initiation, promotion, and progression. Mouse models have been extensively used to analyze the genetic basis of cancer susceptibility. They have led to the identification of multiple loci that confer, either alone or in specific combinations, an increased susceptibility to cancer, some of which have direct translatability to human cancer. Additionally, wild-derived inbred mouse strains are an advantageous reservoir of novel genetic polymorphisms of cancer susceptibility genes, because of the evolutionary divergence between wild and classical inbred strains. Here, we review mapped Stmm (skintumor modifier of MSM) loci using a Japanese wild-derived inbred mouse strain, MSM/Ms, and describe recent advances in our knowledge of the genes responsible for Stmm loci in the 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) two-stage skin carcinogenesis model.

The Japanese Wild-Derived Inbred Mouse Strain, MSM/Ms in Cancer Research

MSM/Ms is a unique inbred mouse strain derived from the Japanese wild mouse, Mus musculus molossinus, which has been approximately 1 million years genetically distant from standard inbred mouse strains mainly derived from M. m. domesticus. Due to its genetic divergence, MSM/Ms has been broadly used in linkage studies. A bacterial artificial chromosome (BAC) library was constructed for the MSM/Ms genome, and sequence analysis of the MSM/Ms genome showed approximately 1% of nucleotides differed from those in the commonly used inbred mouse strain, C57BL/6J. Therefore, MSM/Ms mice are thought to be useful for functional genome studies. MSM/Ms mice show unique characteristics of phenotypes, including its smaller body size, resistance to high-fat-diet-induced diabetes, high locomotive activity, and resistance to age-onset hearing loss, inflammation, and tumorigenesis, which are distinct from those of common inbred mouse strains. Furthermore, ES (Embryonic Stem) cell lines established from MSM/Ms allow the MSM/Ms genome to be genetically manipulated. Therefore, genomic and phenotypic analyses of MSM/Ms reveal novel insights into gene functions that were previously not obtained from research on common laboratory strains. Tumorigenesis-related MSM/Ms-specific genetic traits have been intensively investigated in Japan. Furthermore, radiation-induced thymic lymphomas and chemically-induced skin tumors have been extensively examined using MSM/Ms.

Genetic modifiers of rodent animal models: the role in cataractogenesis

Visual impairment leads to a decrease in quality of life. Cataract is the most commonly observed ocular disease in humans that causes vision disorders. The risk factors associated with cataract development include aging, infections, eye injuries, environmental causes, such as radiation and exposure to ultraviolet rays in sunlight, and genetic mutations. Additionally, several cataract patients display phenotypic heterogeneity, suggesting the role of genetic modifiers in the modulation of severity and onset time of cataractogenesis. However, the genetic modifiers associated with cataract have not been identified in humans yet. In contrast, the identification and mapping of genetic modifiers have been successfully carried out in mice and rats. In this review, we focus on the genetic modifiers of cataract in the rodent models.

A Polymorphic Variant in p19Arf Confers Resistance to Chemically Induced Skin Tumors by Activating the p53 Pathway

Identification of the specific genetic variants responsible for the increased susceptibility to familial or sporadic cancers is important. Using a forward genetics approach to map such loci in a mouse skin cancer model, we previously identified a strong genetic locus, Stmm3, conferring resistance to chemically induced skin papillomas on chromosome 4. Here, we report the cyclin-dependent kinase inhibitor gene Cdkn2a/p19^Arf as a major responsible gene for the Stmm3 locus. We provide evidence that the function of Stmm3 is dependent on p53 and that p19^ArfMSM confers stronger resistance to papillomas than p16^Ink4aMSMin vivo. In addition, we found that genetic polymorphism in p19^Arf between a resistant strain, MSM/Ms (Val), and a susceptible strain, FVB/N (Leu), alters the susceptibility to papilloma development, malignant conversion, and the epithelial-mesenchymal transition. Moreover, we demonstrated that the p19^ArfMSM allele more efficiently activates the p53 pathway than the p19^ArfFVB allele in vitro and in vivo. Furthermore, we found polymorphisms in CDKN2A in the vicinity of a polymorphism in mouse Cdkn2a associated with the risk of human cancers in the Japanese population. Genetic polymorphisms in Cdkn2a and CDKN2A may affect the cancer risk in both mice and humans.

Mapping of new skin tumor susceptibility loci by a phenotype-driven congenic approach

As cancer susceptibility varies among mouse strains, mouse models are powerful tools for the identification of genes responsible for cancer development. Several cancer susceptibility loci have been mapped by genetic analysis using cancer-resistant and cancer-susceptible mouse strains. However, only a few corresponding genes for these loci have been identified, because most of the cancer susceptibility loci are low-penetrance alleles. We reported previously that wild-derived PWK mice showed no tumor development on treatment with the two-stage skin carcinogenesis protocol [induced by 7.12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)], and that this phenotype is dominant-resistant when crossed with the highly susceptible strain FVB. From the analysis of the F1 backcross generation between PWK and FVB, we have mapped the new significant locus Skts-fp1 on chromosome 4. In the present study, congenic strains were generated with the PWK resistance allele in the FVB background using a phenotype-driven approach, and sought to narrow down the candidate loci and find the responsible gene(s). One of the resistant mice in the N₆ generation carried the remaining PWK allele on chromosomes 4, 7 and 11, and an association study using the progeny of this mouse suggested that the locus on chromosome 11 may affect the cancer susceptibility locus on chromosome 7. On the other hand, no skin tumor susceptibility locus was mapped on chromosome 11 as examined in N2 progeny. These findings suggest that there is at least one tumor-resistance gene on chromosome 7, the function of which could be regulated by gene(s) located on chromosome 11.