• BMB Reports
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• v.52 no.3
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• pp.208-213
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• 2019

Chemoresistance is the primary obstacle in the treatment of locally advanced and metastatic nasopharyngeal carcinoma (NPC). Recent evidence suggests that the transcription factor forkhead box M1 (FoxM1) is involved in chemoresistance. Our group previously confirmed that FoxM1 is overexpressed in NPC. In this study, we investigated the role of FoxM1 in cisplatin resistance of the cell lines 5-8F and HONE-1 and explored its possible mechanism. Our results showed that FoxM1 and NBS1 were both overexpressed in NPC tissues based on data from the GSE cohort (GSE12452). Then, we measured FoxM1 levels in NPC cells and found FoxM1 was overexpressed in NPC cell lines and could be stimulated by cisplatin. MTT and clonogenic assays, flow cytometry, ${\gamma}H2AX$ immunofluorescence, qRT-PCR, and western blotting revealed that downregulation of FoxM1 sensitized NPC cells to cisplatin and reduced the repair of cisplatin-induced DNA double-strand breaks via inhibition of the MRN (MRE11-RAD50-NBS1)-ATM axis, which might be related to the ability of FoxM1 to regulate NBS1. Subsequently, we demonstrated that enhanced sensitivity of FoxM1 knockdown cells could be reduced by overexpression of NBS1. Taken together, our data demonstrate that downregulation of FoxM1 could improve the sensitivity of NPC cells to cisplatin through inhibition of MRN-ATM-mediated DNA repair, which could be related to FoxM1-dependent regulation of NBS1.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4739-4743
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• 2012

Background: Predictive biomarkers for lung cancer recurrence after curative tumor resection remain unclear. This study set out to assess the role of FoxM1 in the recurrence of non-small cell lung cancer. Methods: Immunohistochemistry for FoxM1 expression was performed on paraffin-embedded tumor tissues from 165 NSCLC patients. Association of FoxM1 expression with clinicopathological parameters and disease free survival were evaluated. Results: Our results indicated FoxM1 expression to be significantly associated with poorer tissue differentiation (P =0.03), higher TNM stage (P <0.01), lymph node metastasis (P <0.01), advanced tumor stage (P <0.01), and poorer disease free survival (P <0.01). Multivariable analysis showed that FoxM1 expression increased the hazard of recurrence (hazard ratio= 1.96, 95% CI, 1.04-3.17, P <0.05), indicating that FoxM1 is an independent and significant predictor of lung cancer recurrence. Conclusion: Therefore, FoxM1 is an independent risk factor for recurrence of NSCLC. Elevated FoxM1 expression could be used as an indicator of poor disease free survival.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.23-29
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• 2015

Background: Current cancer therapy mainly focuses on identifying novel targets crucial for tumorigenesis. The FoxM1 is of preference as an anticancer target, due to its significance in execution of mitosis, cell cycle progression, as well as other signal pathways leading to tumorigenesis. FoxM1 is partially regulated by oncoproteins or tumor suppressors, which are often mutated, lost, or overexpressed in human cancer. Since sustaining proliferating signaling is an important hallmark of cancer, FoxM1 is overexpressed in a series of human malignancies. Alarge-scale gene expression analysis also identified FoxM1 as a differentially-expressed gene in most solid tumors. Furthermore, overexpressed FoxM1 is correlated with the prognosis of cancer patients, as verified in a series of malignancies by Cox regression analysis. Thus, extensive studies have been conducted to explore the roles of FoxM1 in tumorigenesis, making it an attractive target for anticancer therapy. Several antitumor drugs have been reported to target or inhibit FoxM1 expression in different cancers, and down-regulation of FoxM1 also abrogates drug resistance in some cancer cell lines, highlighting a promising future for FoxM1 application in the clinic.

• Biomedical Science Letters
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• v.14 no.4
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• pp.243-248
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• 2008

The Forkhead box M1 (FoxM1) has been shown to regulate transcription of cell cycle genes essential for $G_1$-S and $G_2$-M progression, including $p27^{kip1}$. The $p27^{kip1}$ gene is a member of the universal cyclin-dependent kinase inhibitor family. Immunohistochemical studies for FoxM1 and $p27^{kip1}$ were performed in 154 lung cancers (69 squamous cell carcinomas (SCC) and 85 adenocarcinomas (ADC)). Immunoreactivity for FoxM1 and $p27^{kip1}$ were found in 79 (51.3%) and 49 (31.8%) out of 154 cases, respectively. Forty-six (58.2%) of the 79 cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression in 154 lung cancers. According to histologic type, 22 (53.7%) of the 41 SCC cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression and 24 (63.2%) of the 38 ADC cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression. The expression of $p27^{kip1}$ was significantly higher in the SCC than in the ADC (P=0.050). There were no significant associations between the FoxM1 and $p27^{kip1}$ expressions and other clinicopathologic factors. These findings suggest that FoxM1 overexpression may diminish the expression of $p27^{kip1}$ protein in lung cancers. Further studies are needed to define the relation between FoxM1 and $p27^{kip1}$ for examining the mechanisms of tissue-specific FoxM1 expression.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.257-264
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• 2022

Colorectal cancer (CRC) is one of the most common malignant tumor. 5-FU is commonly used for the treatment of CRC. However, the development of drug resistance in tumor chemotherapy can seriously reduce therapeutic efficacy of 5-FU. Recent data show that FoxM1 is associated with 5-FU resistance in CRC. FoxM1 plays a critical role in the carcinogenesis and drug resistance of several malignancies. It has been reported that urushiol V isolated from the cortex of Rhus verniciflua Stokes is cytotoxic to several types of cancer cells. However, the underlying molecular mechanisms for its antitumor activity and its potential to attenuate the chemotherapeutic resistance in CRC cells remain unknown. Here, we found that urushiol V could inhibit the cell proliferation and induced S-phase arrest of SW480 colon cancer cells. It inhibited protein expression level of FoxM1 through activation of AMPK. We also investigated the combined effect of urushiol V and 5-FU. The combination treatment reduced FoxM1 expression and consequently reduced cell growth and colony formation in 5-FU resistant colon cancer cells (SW480/5-FUR). Taken together, these result suggest that urushiol V from Rhus verniciflua Stokes can suppress cell proliferation by inhibiting FoxM1 and enhance the antitumor capacity of 5-FU. Therefore, urushiol V may be a potential bioactive compound for CRC therapy.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.241-247
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• 2020

The effect of radiofrequency radiation (RF) exposure on mouse associated with the exercise was investigated in the brain at the molecular level. The expression of tyrosine hydroxylase(TH), FoxO3a, AMPKα and mRNA was investigated by real-time RT-PCR in striatum and the hypothalamus. In the striatum, TH mRNA expression was decreased in the exercise and RF exposure group. FoxO3a mRNA expression was significantly increased in the spontaneous exercise group and a significant decrease was observed in the RF exposure and spontaneous exercise group. In the hypothalamus, TH mRNA expression was significantly decreased in the RF exposure and spontaneous exercise group. But, FoxO3a mRNA expression was significantly increased in the RF exposure and spontaneous exercise group. We will further investigate the expression of protein molecules in the hippocampus of the brain to reveal the effects of RF radiation on memory.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.4
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• pp.499-509
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• 2008

Foxo1 plays an important role in the integration of hormone-activated signaling pathways with the complex transcriptional cascade that promotes preadipocyte differentiation of clonal cell lines from rodents. We isolated the full-length cDNA of porcine FoxO1 gene using RACE, confirmed by visual Northern blotting. The deduced amino acids indicated 94% and 90% identities with the corresponding human and mice aa. Analysis of the aa sequence, showed that it included a Forkhead domain (aa 167-247), a transmembrane structure domain (aa 90-113), a LXXLL motif (aa 469-473), and 51 Ser, 8 Thr, and 4 Tyr phosphorylation sites, indicating a potential important role for FoxO1 transcriptional activity in vivo. Using the IMpRH panel, we mapped FoxO1 gene to chromosome 11p13. Our data provide basic molecular information useful for the further investigation on the function of FoxO1 gene. Time-course analysis of FoxO1 expressions indicated that levels of mRNA and protein gradually increased from day 0 to 3, and it reached almost maximal level at day 3, then decreased from day 5 to 7 in porcine primary preadipocyte differentiation. After induction by IGF-1, GPDH activity and accumulation of lipid increased, however, expressions of FoxO1 mRNA and protein were inhibited in a dose dependent manner. These results suggest that FoxO1 takes part in porcine preadipocyte differentiation and expressions of FoxO1 were regulated by IGF-1.

• The Plant Pathology Journal
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• v.30 no.2
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• pp.136-150
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• 2014

Although multiple transcription factors (TFs) have been characterized via mutagenesis to understand their roles in controlling pathogenicity and infection-related development in Magnaporthe oryzae, the causal agent of rice blast, if and how forkhead-box (FOX) TFs contribute to these processes remain to be characterized. Four putative FOX TF genes were identified in the genome of M. oryzae, and phylogenetic analysis suggested that two of them (MoFKH1 and MoHCM1) correspond to Ascomycota-specific members of the FOX TF family while the others (MoFOX1 and MoFOX2) are Pezizomycotina-specific members. Deletion of MoFKH1 (${\Delta}Mofkh1$) resulted in reduced mycelial growth and conidial germination, abnormal septation and stress response, and reduced virulence. Similarly, ${\Delta}Mohcm1$ exhibited reduced mycelial growth and conidial germination. Conidia of ${\Delta}Mofkh1$ and ${\Delta}Mohcm1$ were more sensitive to one or both of the cell cycle inhibitors hydroxyurea and benomyl, suggesting their role in cell cycle control. On the other hand, loss of MoFOX1 (${\Delta}Mofox1$) did not show any noticeable changes in development, pathogenicity, and stress response. Deletion of MoFOX2 was not successful even after repeated attempts. Taken together, these results suggested that MoFKH1 and MoHCM1 are important in fungal development and that MoFKH1 is further implicated in pathogenicity and stress response in M. oryzae.

• Communications of the Korean Mathematical Society
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• v.30 no.2
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• pp.103-108
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• 2015

Fox [2] presented an interesting identity for $_pF_q$ which is expressed in terms of a finite summation of $_pF_q$'s whose involved numerator and denominator parameters are different from those in the starting one. Moreover Fox [2] found a very interesting and general summation formula for $_3F_2(1/2)$ as a special case of his above-mentioned general identity with the help of Kummer's second summation theorem for $_2F_1(1/2)$. Here, in this paper, we show how two general summation formulas for $$_3F_2\[\array{\hspace{110}{\alpha},{\beta},{\gamma};\\{\alpha}-m,\;\frac{1}{2}({\beta}+{\gamma}+i+1);}\;{\frac{1}{2}}\]$$, m being a nonnegative integer and i any integer, can be easily established by suitably specializing the above-mentioned Fox's general identity with, here, the aid of generalizations of Kummer's second summation theorem for $_2F_1(1/2)$ obtained recently by Rakha and Rathie [7]. Several known results are also seen to be certain special cases of our main identities.

• Journal of the Korean Mathematical Society
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• v.13 no.1
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• pp.15-18
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• 1976