Intellectual disability, macrocephaly and seizures caused by de novo variants in PAK1: a case report / 中华实用儿科临床杂志

The clinical data of a child with intellectual disability, macrocephaly and seizures associated with de novo variants in the PAK1 gene who was treated in the Department of Pediatrics, Peking University First Hospital in March 2022 were retrospectively analyzed.Meanwhile, literature review was performed to analyze the pathogenicity and mutation characteristics of the PAK1 gene.A boy with 4 years and 8 months old presented clinical manifestations of intellectual disability dominated by speech impairment and recurrent epilepsy.The patient had special facial features, including large head circumference, long face and low nose beam.Video electroencephalogram showed slow waves in the bilateral anterior head regions, and sharp wave, spike-slow complex waves and sharp-slow complex waves in the left hemisphere.Head magnetic resonance imaging revealed enlargement of the bilateral cerebral gyri, cerebellum and brainstem, thickening of cortex and corpus callosum, and enrichment of white matter.A de novo heterozygous mutation c. 361C>A(p.Pro121Thr ) was found in exon 4 of PAK1 (NM_001128620). This article for the first time reported a case of intellectual disability, macrocephaly and seizures caused by the de novo variants in the PAK1 gene in China.The pathogenic gene in this family was identified, which provided the possibility for accurate genetic counseling.

The effect of miR-485-5p on cisplatin resistance of colon cancer cells / 中华老年医学杂志

Objective:To investigate the effect of miR-485-5p on cisplatin resistance of colon cancer cells through the PI3K/Akt-PAK1 signaling pathway.Methods:The LoVo/DDP cell lines were constructedand divided into an NC group(without transfection treatment), an miR-485-5p mimics group(transfected with miR-485-5p mimics), an miR-485-5p inhibitors group(transfected with miR-485-5p inhibitors), an IPA-3 group(intervention with IPA-3)and an miR-485-5p mimics+ IPA-3 group(transfection with miR-485-5p mimics andinterventionwith IPA-3), with all given 0, 3, and 5 μmol/L cisplatin treatment.Results:Among the 20 patients, the proportion of negative miR-485-5p detection was 85.0%(17/20), and the proportion of positive detection was 15.0%(3/20); the proportion of negative PAK1 detection was 20.0%(4/20), and the proportion of positive detection was 80.0%(16/20). The expression of miR-485-5p in colon cancer tissue was significantly lower than that in adjacent tissues( P<0.05); the expression of miR-485-5p in the human colon cancer cell lines LoVo, SW620, HCT116, and SW480 was all lower than in normal intestinal mucosal cells( P<0.05); the expression of miR-485-5p in LoVo/DDP was significantly lower than inLoVo( P<0.001). Under the action of 3 μmol/L and 5 μmol/L cisplatin, LoVo/DDP had highercell viability but a lower apoptosis rate than LoVo( P<0.001). The cell survival rate in the miR-485-5p mimics group was significantly lower than that in the miR-485-5p inhibitors group( P<0.001). Compared with the NC mimics group, overexpression of miR-485-5p significantly down-regulated luciferase activity of the wild-type PAK1 reporter gene( P<0.001); P-PI3k, P-Akt and PAK1levels in the miR-485-5p mimics group were significantly lower than in the miR-485-5p inhibitors group( P<0.001); the cell survival rate in the miR-485-5p mimics group, the IPA-3 group and the miR-485-5p mimics+ IPA-3 group was significantly lower than in the NC group( P<0.001)and the cell survival rate in the miR-485-5p mimics+ IPA-3 group was significantly lower than in the miR-485-5p mimics group( P<0.001). Conclusions:Up-regulation of miR-485-5p reverses colon cancer cisplatin resistance through the PI3K/Akt-PAK1signaling pathway, suggesting that overexpression of miR-485-5p or inhibition of the PI3K/Akt-PAK1signaling pathway enhances the therapeutic efficacy of cisplatin in colon cancer.

Expressions and Significance of Livin, Survivin, Pak-1 and Caspase-7 in Different Gastric Mucosal Lesions / 胃肠病学

Background: Livin, survivin and Pak-1 are all related to the occurrence and development of gastric cancer. Livin and survivin play their roles by inhibiting the activity of caspase-7. Aims: To investigate the expressions and significance of livin, survivin, Pak-1 and caspase-7 in different gastric mucosal lesions. Methods: A total of 45 cases of gastric cancer and paracancerous tissue, 45 chronic atrophic gastritis with intestinal metaplasia, 45 chronic non-atrophic gastritis from Jan. 2015 to Dec. 2019 at the Second Affiliated Hospital of Baotou Medical College were collected. Immunohistochemistry was used to detect the expressions of livin, survivin, Pak-1 and caspase-7, and their correlations with clinicopathological features of gastric cancer patients were analyzed. Results: Compared with chronic non-atrophic gastritis group and paracancerous group, the positivity expression rates of livin, survivin and Pak-1 in intestinal metaplasia group were significantly increased (P<0.05), while caspase-7 was significantly decreased (P<0.05). Compared with intestinal metaplasia group, the positivity expression rates of livin, survivin and Pak-1 in gastric cancer group were significantly increased (P<0.05), while caspase-7 was significantly decreased (P<0.05). Expressions of livin, survivin, Pak-1 and caspase-7 were correlated with the differentiation degree, TNM stage, depth of infiltration and lymph node metastasis in patients with gastric cancer (P<0.05). Conclusions: Livin, survivin, Pak-1 and caspase-7 play important roles in the occurrence and development of gastric cancer.

A mechanism research of novel inhibitor of PAK1 inducing colorectal cancer DLD-1 apoptosis / 中国药科大学学报

@#PAK1 plays an important role in the development of tumors. It is of great significance to screen and develop new PAK1 inhibitors as targeted drugs for cancer treatment. The traditional PAK1 inhibitor screening method has the problems of high cost and low efficiency. Computer virtual screening can reduce the cost of finding active lead compounds and improve the screening efficiency. In this study, a kind of PAK1 candidate compound was screened by computer assisted virtual screening combined with Z′lyteTM high flux kinase screen. In vitro enzyme activity screening showed that compound 18(K788)had good PAK1 inhibitory activity(inhibition rate was 42. 7%). Furtherly by MTT detection, it was found that K788 had significant PAK1 positive tumor killing activity, which was even better than the positive drug IPA-3. Flow cytometry and Western Blot showed that K788 could activate caspase apoptosis pathway and induce apoptosis of colon cancer cell DLD-1 by inhibiting PAK1 expression and activation. K788 has great potential for clinical development and application, and can be used as a PAK1 target for further research.

A proteomic analysis of effects ofβ-elemene on human gastric cancer cell line SGC7901 / 西安交通大学学报(医学版)

Objective To investigate the effect of β-elemene on SGC7901 gastric cancer cell line and the potential proteins involved. Methods Human SGC7901 gastric cancer cells were treated with different concentrations ofβ-elemene.Cell viability was assessed.A proteomic method,isobaric tags for relative and absolute quantitation (iTRAQ),was employed to detect the proteins altered by β-elemene.Protein expression was validated by Western blot.Results β-elemene inhibited the viability of SGC7901 gastric cancer cells in a dose-dependent manner.Altogether,147 upregulated proteins and 86 downregulated proteins were identified in response to β-elemene treatment in SGC7901 gastric cancer cell line.Among them,the expressions of p21-activated protein kinase-interacting protein 1 (PAK1IP1 ),Bcl-2-associated transcription factor 1 (BTF)and topoisomerase 2-alpha (TOPIIα)were validated by Western blot and the trends were consistent with iTRAQ results.Top pathways involved inβ-elemene treatment in SGC7901 gastric cancer cell line included ribosome signaling,peroxisome proliferator-activated receptors (PPARs)signaling pathway,regulation of actin cytoskeleton,phagosome,biosynthesis and metabolism of some amino acids.Conclusion Our results suggest a promising therapeutic role of β-elemene for gastric cancer.The differentially expressed proteins give us better insights into the potential mechanisms involved in gastric cancer treatment using β-elemene.

A new tale of p21 activated protein kinase in the heart:pathophysiology to drug discovery / 中国药理学与毒理学杂志

CardiovascuIar disease is the number one cause for morbidity and mortaIity worIdwide. Possi-biIities for new therapies in the emerging fieId of cardiac signaIIing prompted extensive research on myocardiaI re-modeIIing over the past decades. In this review,we as-sembIe an overview of the recent findings on the muIti-functionaI enzyme,p21-activated kinase 1( Pak1),a member of a serine/ threonine protein kinase famiIy in the heart,particuIarIy its cardiac protective effects. We pres-ent a modeI for Pak1 signaIing that provides a mecha-nism for specificaIIy affecting cardiac ceIIuIar processes. We discuss its cardiac protective effects such as anti-hy-pertrophy,anti-ischaemic injury and roIe in maintaining ventricuIar Ca2+ homeostasis and eIectrophysioIogicaI stabiIity under physioIogicaI, β-adrenergic and hyper-trophic stress conditions.We aIso discuss the potentiaIs of Pak1 activation by naturaIIy occurring sphingosine and its anaIogues FTY720,and bioactive peptides designed to diminish Pak1 auto-inhibition as noveI thera-peutics for major cardiovascuIar diseases.

Pak1/LIMK1/Cofilin Pathway Contributes to Tumor Migration and Invasion in Human Non-Small Cell Lung Carcinomas and Cell Lines

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) are the major histological types of non-small cell lung carcinoma (NSCLC). Although both SCCs and ACs have been characterized histologically and clinically, the precise mechanisms underlying their migration and invasion are not yet known. Here, we address the involvement in NSCLC of the p21-associated kinase1 (Pak1)/LIM kinase1 (LIMK1)/cofilin pathway, which recently has been reported to play a critical role in tumor migration and invasion. The Pak1/LIMK1/cofilin pathway was evaluated in tumors from SCC (n=35) and AC (n=35) patients and in SCC- and AC-type cell lines by western blotting, immunohistochemistry, and in vitro migration and invasion assays. The levels of phosphorylated Pak1, LIMK1, and cofilin in lung tumor tissues from SCC patients were increased as compared to normal tissues. In addition, immunohistochemistry showed greater expression of phosphorylated cofilin in SCC tissues. Expression of phosphorylated Pak1 and LIMK1 proteins was also significantly higher in SCC-type cells than in AC-type cells. Moreover, migration and invasion assays revealed that a higher percentage of SCC type cells exhibited migration and invasion compared to AC type cells. Migration was also decreased in LIMK1 knockdown SK-MES-1 cells. These findings suggest that the activation of the Pak1/LIMK1/cofilin pathway could preferentially contribute to greater tumor migration and invasion in SCC, relative to that in AC.

Expression and clinical significance of p21-activated kinase 1 in colorectal carcinoma / 肿瘤研究与临床

Objective To investigate the expression of p21-activated kinase 1 (PAK1) protein in patients with colorectal carcinoma and evaluate its clinicopathological significance. Methods The expression of PAK1 was detected by the immunohistochemical method (SABC) in 50 cases of colorectal carcinoma and pericancerous normal specimens, and the relationship between the expression of PAK1 protein and clinicopathological parameters was analyzed. Results The positive rate of PAK1 in colorectal carcinoma was significantly higher than that in normal pulmonary tissues (58 % vs 22 %, P <0.01), and the expression of PAK1 protein was significantly correlated to lymph node metastasis (χ2 =8.872, P =0.003) and degree of differentiation (χ2 =6.344, P =0.042), but not to tumor location, size, age and sex (P >0.05). The positive staining of PAK1 protein was mainly located in the cytoplasm of tumor cells. Conclusion Overexpression of PAK1 is closely related with tumor biological behavior and it may play important role in the development of colorectal carcinoma.