• Journal of Life Science
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• v.30 no.10
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• pp.867-876
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• 2020

This study investigated the repair of UVB-induced cell damage by magnolol. We performed a drug-repurposing screen, and, in the STAT3 reporter gene assay, magnolol was identified as a suppressor of STAT3 that improves the cell viability of HDF cells. HDF cells treated with IL-6, UVB, and IFNγ showed the highest expression of Jak2 and phosphorylated STAT3 (p-STAT3), and magnolol was able to decrease the expression of Jak2 and p-STAT3 in UVB-induced cells. Moreover, UVB-damaged cell growth increased significantly in correlation with both reactivation and with magnolol in a dose-dependent manner. Compared with AG490 (a Jak2 inhibitor) treatment of UVB-treated HDF cells, cell proliferation increased significantly. We confirmed that AG490 and magnolol reduced TNF-α concentrations, and Western blotting (protein level) showed decreases in Jak2 and p-STAT3 expression in only the magnolol-treated cells. The expression of Jak2, p-STAT3, and SOCS3 also increased only after treatment with magnolol. Cells were treated with magnolol and ML385 (an NRF2 inhibitor), and these secondary metabolites reduced cell proliferation and NRF2 expression. The amount of MMP9 was also increased by cotreatment with magnolol and ML385. Collectively, these results demonstrate the potential of magnolol for repairing cells after UVB-induced damage by regulating the expression of NRF2, SOCS3, Jak2, and STAT3.

• BMB Reports
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• v.54 no.12
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• pp.626-631
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• 2021

Janus kinase 2 (JAK2), a non-receptor tyrosine kinase, is a critical component of cytokine and growth factor signaling pathways regulating hematopoietic cell proliferation. JAK2 mutations are associated with multiple myeloproliferative neoplasms. Although physiological and pathological functions of JAK2 in hematopoietic tissues are well-known, such functions of JAK2 in the nervous system are not well studied yet. The present study demonstrated that JAK2 could negatively regulate neuronal differentiation of mouse embryonic stem cells (ESCs). Depletion of JAK2 stimulated neuronal differentiation of mouse ESCs and activated glycogen synthase kinase 3β, Fyn, and cyclin-dependent kinase 5. Knockdown of JAK2 resulted in accumulation of GTP-bound Rac1, a Rho GTPase implicated in the regulation of cytoskeletal dynamics. These findings suggest that JAK2 might negatively regulate neuronal differentiation by suppressing the GSK-3β/Fyn/CDK5 signaling pathway responsible for morphological maturation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1053-1055
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• 2016

Background: Polycythemia rubra vera (PV), being a primary polycythemia, is caused by neoplastic proliferation of erythroid, megakaryocytic and granulocytic lineages which result in panmyelosis. PV patients have a somatic acquired mutation in the Janus kinase (JAK2) pathway, rendering cell proliferation independent of the normal regulatory mechanisms that regulate erythropoiesis. The rational of this study was to determine the prevalence of the JAK-2 V617F mutation in Pakistani patients with PV. Materials and Methods: In this cross sectional study, 26 patients with PV were enrolled from January 2010 to December 2014. Patients were diagnosed based on WHO criteria for PV. All were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR. Results: The mean age was $53.4{\pm}9.31years$ (range 36-72) and the male to female ratio was 2:1. The frequency of JAK2 V617F positivity in our PV patients was found to be 92.3%. Overall 30.7% of patients were asymptomatic and remaining 69.3% presented with symptomatic disease. The mean hemoglobin was $18.1{\pm}1.9g/dl$ with the mean hematocrit of $55.6{\pm}8.3%$. The mean total leukocyte count was $12.8{\pm}7.1{\times}10^9/l$ and the platelet count was $511{\pm}341.9{\times}10^9/l$. A positive correlation of JAK2 V617F mutation was established with high TLC count (P=0.01). No correlation of JAK2 V617F could be established with age or gender (P>0.05). Conclusions: The JAK2 V617F mutation frequency in our PV patients was similar to those reported internationally. Screening for the mutation in all suspected PV cases could be beneficial in differentiating patients with reactive and clonal erythrocytosis.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.923-926
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• 2016

The classic BCR-ABL1-negative myeloproliferative neoplasm is an operational sub-category of MPNs that includes polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The JAK2V617F mutation is found in ~ 95% of PV and 50-60% of ET or PMF. In most of the remaining JAK2V617F-negative PV cases, JAK2 exon 12 mutations are present. Amongst the JAK2V617F-negative ET or PMF 5-10% of patients carry mutations in the MPL gene. Prior to 2013, there was no specific molecular marker described in the remaining 30-40% ET and PMF. In December 2013, two research groups independently reported mutations in the gene CALR found specifically in ET (67-71%) and PMF (56-88%) but not in PV. Initially CALR mutations were reported mutually exclusive with JAK2 or MPL. However, co-occurrence of CALR mutations with JAK2V617F has been reported recently in a few MPN cases. Many studies have reported important diagnostic and prognostic significance of CALR mutations in ET and PMF patients and CALR mutation screening has been proposed to be incorporated into WHO diagnostic criteria for MPN. It is suggestive in diagnostic workup of MPN that CALR mutations should not be studied in MPN patients who carry JAK2 or MPL mutations. However JAK2V617F and CALR positive patients might have a different phenotype and clinical course, distinct from the JAK2-positive or CALR-positive subgroups and identification of the true frequency of these patients may be an important factor for defining the prognosis, risk factors and outcomes for MPN patients.

• Biomolecules & Therapeutics
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• v.30 no.1
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• pp.72-79
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• 2022

Licochalcone H (LCH) is a phenolic compound synthetically derived from licochalcone C (LCC) that exerts anticancer activity. In this study, we investigated the anticancer activity of LCH in human skin cancer A375 and A431 cells. The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay was used to evaluate the antiproliferative activity of LCH. Cell cycle distribution and the induction of apoptosis were analyzed by flow cytometry. Western blotting assays were performed to detect the levels of proteins involved in cell cycle progression, apoptosis, and the JAK2/STAT3 signaling pathway. LCH inhibited the growth of cells in dose- and time-dependent manners. The annexin V/propidium iodide double staining assay revealed that LCH induced apoptosis, and the LCH-induced apoptosis was accompanied by cell cycle arrest in the G1 phase. Western blot analysis showed that the phosphorylation of JAK2 and STAT3 was decreased by treatment with LCH. The inhibition of the JAK2/STAT3 signaling pathway by pharmacological inhibitors against JAK2/STAT3 (cryptotanshinone (CTS) and S3I-201) simulated the antiproliferative effect of LCH suggesting that LCH induced apoptosis by modulating JAK2/STAT3 signaling.

• Biomolecules & Therapeutics
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• v.24 no.5
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• pp.489-494
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• 2016

Neuropathic pain (NPP) is the main culprit among chronic pains affecting the normal life of patients. Procaine is a frequently-used local anesthesia with multiple efficacies in various diseases. However, its role in modulating NPP has not been reported yet. This study aims at uncovering the role of procaine in NPP. Rats were pretreated with procaine by intrathecal injection. Then NPP rat model was induced by sciatic nerve chronic compression injury (CCI) and behavior tests were performed to analyze the pain behaviors upon mechanical, thermal and cold stimulations. Spinal expression of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) was detected by qRT-PCR and western blot. JAK2 was also overexpressed in procaine treated model rats for behavior tests. Results showed that procaine pretreatment improved the pain behaviors of model rats upon mechanical, thermal and cold stimulations, with the best effect occurring on the $15^{th}$ day post model construction (p<0.05). Procaine also inhibited JAK2 and STAT3 expression in both mRNA (p<0.05) and protein levels. Overexpression of JAK2 increased STAT3 level and reversed the improvement effects of procaine in pain behaviors (p<0.01). These findings indicate that procaine is capable of attenuating NPP, suggesting procaine is a potential therapeutic strategy for treating NPP. Its role may be associated with the inhibition on JAK2/STAT3 signaling.

• Journal of Acupuncture Research
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• v.29 no.1
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• pp.47-59
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• 2012

목적 : 이 연구는 봉독이 사람의 난소암 세포인 SKOV3와 PA-1에서 death receptor의 발현을 높여 세포자멸사를 촉진함으로써 암세포의 성장을 억제하는지 밝히고자 하였다. 방법 : 난소암의 세포자멸사의 관찰에는 DAPI, TUNEL staining assay를 시행하였으며, 세포자멸사 조절 단백질의 변동 관찰에는 western blot analysis를 시행하였고, 난소암 세포에서 death receptor의 변화를 관찰하기 위해 RT-PCR analysis를 시행하였다. 결과 : 1. DAPI, TUNEL staining assay 결과, 봉독은 투여량에 따라 세포자멸사의 유도를 통해 SKOV3와 PA-1 난소암세포의 증식을 억제하였고, 세포자멸사와 동반하여 DR4와 DR6의 발현이 두 암세포 모두에서 증가하였고, DR3의 출현은 PA-1 세포에서 증가하였다. 2. Death Receptor의 발현 증가에 따라 caspase-3, 8, 9 and Bax를 포함하는 세포자멸사 촉진 단백질의 발현이 동반하여 상승하였고 JAK2, STAT3의 인산화와 Bcl-2의 발현은 억제되었다. 3. siRNA 처리 시 봉독에 의한 DR3, DR4, DR6 발현증가와 STAT3의 활성억제가 역전되었다. 결론 : 이러한 결과는 봉독이 난소암 세포에서 DR3, DR4, DR6의 증가와 JAK2/STAT3 pathway의 억제를 통하여 세포자멸사를 유발한다는 것을 시사하며, 난소암의 예방과 치료에 효과적으로 활용될 수 있을 것으로 기대된다.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.10
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• pp.4647-4653
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• 2016

Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical presentation, disease progression, and treatment outcome. Material and Methods: Pyrosequencing was performed to detect JAK2 (V617F) and MPL (W515K/L) and capillary electrophoresis to identify CALR exon 9 mutations in 100 samples of Ph-negative MPNs (38.0 PV, 55 ET, 4 PMF, and 3 MPN-U). Results: The results showed somatic mutations of JAK2 (V617F) in 94.7% of PV, 74.5% of ET, 25.0% of PMF, and all MPN-U. A high proportion of JAK2 (V617F) mutant allele burden (mutational load > 50.0%) was predominantly observed in PV when compared with ET. Although a high level of JAK2 (V617F) allele burden was strongly associated with high WBC counts in both PV and ET, several hematological parameters (hemoglobin, hematocrit, and platelet count) were independent of JAK2 (V617F) mutational load. MPL (W515K/L) mutations could not be detected whereas CALR exon 9 mutations were identified in 35.7% of patients with JAK2 negative ET and 33.3% with JAK2 negative PMF. Conclusions: The JAK2 (V617F) allele burden may be involved in progression of MPNs. Furthermore, a high level of JAK2 (V617F) mutant allele appears strongly associated with leukocytosis in both PV and ET.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7889-7892
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• 2015

Background: Primary idiopathic myelofibrosis (PMF) is a clonal Ph-chromosome negative myeloproliferative neoplasm characterized by dysregulated kinase signaling and release of abnormal cytokines. In the recent past, following JAK2 V617F mutation invention, important revolution has been made in the molecular diagnostic biology of this disease. The rational of this study was to determine the mutational status of JAK2 V617F in Pakistan patients with PMF. Materials and Methods: In this cross sectional study, 20 patients with PMF were enrolled from January 2011 to December 2014. Diagnosis was based on WHO criteria for PMF. All patients were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by allele specific PCR. Results: The mean age was $57.9{\pm}16.5years$. The male to female ratio was 3:1. The frequency of JAK2 V617F positivity in our PMF patients was found to be 55%. Positive correlations of JAK2 V617F mutation were established with high TLC count, raised LDH and marked splenomegaly (P<0.05). No correlation of JAK2 V617F could be established with age and gender (P>0.05). Conclusions: The JAK2 V617F mutation frequency in our PMF patients was similar to those reported previously. In our hands JAK2 V617F mutated patients expressed an aggressive disease phenotype. Screening for the mutation in all suspected PMF cases could be beneficial in differentiating patients with reactive and clonal marrow fibrosis.

• Molecules and Cells
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• v.23 no.1
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• pp.94-99
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• 2007

Suppressors of cytokine signaling (SOCS) family members are negative feedback regulators of the Jak/Stat pathway, which is an essential inflammatory signaling pathway. We investigated expression of eight members of the SOCS family in rat astrocytes, using two inflammatory stimulants, PMA and IFN-${\gamma}$. Only a few SOCS genes were induced by both stimulants, and we detected an increase in SOCS5 protein with PMA. PMA activated the Jnk, Erk, p38, and Jak/Stat signal pathways. In addition, it increased the level of activated-Stat3 resulting from tyrosine phosphorylation. A gel-shift assay showed that a protein in nuclear extracts from PMA-treated cells was able to bind to Stat binding elements. These results suggest that activated Stat3 binds to SOCS promoters and leads to their transcriptional induction.