Xia Xi

Dr. Xia Xi

Peking University Shenzhen Hospital, Shenzhen, Guangdong, China

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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21 September 2011 in BMC Cancer
Verified
Journal Article
Open access
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Xia XiXia Xi
Xia Xi
QMQuanfu Ma
Quanfu Ma
XLXiao Li
Xiao Li
TJTeng Ji
Teng Ji
PCPingbo Chen
Pingbo Chen
DMDing Ma
Ding Ma
Background: P21(WAF1/Cip1) binds to cyclin-dependent kinase complexes and inhibits their activities. It was originally described as an inhibitor of cancer cell proliferation. However, many recent studies have shown that p21 promotes tumor progression when accumulated in the cell cytoplasm. So far, little is known about the correlation between cytoplasmic p21 and drug resistance. This study was aimed to investigate the role of p21 in the cisplatin resistance of ovarian cancer. Methods: RT-PCR, western blot and immunofluorescence were used to detect p21 expression and location in cisplatin-resistant ovarian cancer cell line C13* and its parental line OV2008. Regulation of cytoplasmic p21 was performed through transfection of p21 siRNA, Akt2 shRNA and Akt2 constitutively active vector in the two cell lines; their effects on cisplatin-induced apoptosis were evaluated by flow cytometry. Tumor tissue sections of clinical samples were analyzed by immunohistochemistry. Results: p21 predominantly localizes to the cytoplasm in C13* compared to OV2008. Persistent exposure to low dose cisplatin in OV2008 leads to p21 translocation from nuclear to cytoplasm, while it had not impact on p21 localization in C13*. Knockdown of cytoplasmic p21 by p21 siRNA transfection in C13* notably increased cisplatin-induced apoptosis through activation of caspase 3. Inhibition of p21 translocation into the cytoplasm by transfection of Akt2 shRNA into C13* cells significantly increased cisplatin-induced apoptosis, while induction of p21 translocation into the cytoplasm by transfection of constitutively active Akt2 in OV2008 enhanced the resistance to cisplatin. Immunohistochemical analysis of clinical ovarian tumor tissues demonstrated that cytoplasmic p21 was negatively correlated with the response to cisplatin based treatment. Conclusions: Cytoplasmic p21 is a novel biomarker of cisplatin resistance and it may represent a potential therapeutic target for ovarian tumors that are refractory to conventional treatment.

3 November 2011 in Molecular Cancer
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Journal Article
Open access
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Xia XiXia Xi
Xia Xi
TJTeng Ji
Teng Ji
PCPingbo Chen
Pingbo Chen
XLXiao Li
Xiao Li
YFYong Fang
Yong Fang
DMDing Ma
Ding Ma
Background: Mesenchymal stem cells (MSCs) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern, kinetic delivery of adenovirus, and therapeutic efficacy of the MSC loading of E1A mutant conditionally replicative adenovirus Adv-Stat3(-) which selectively replicated and expressed high levels of anti-sense Stat3 complementary DNA in breast cancer and melanoma cells. Methods: We assessed the release ability of conditionally replicative adenovirus (CRAd) from MSC using crystal violet staining, TCID50 assay, and quantitative PCR. In vitro killing competence of MSCs carrying Adv-Stat3(-) toward breast cancer and melanoma was performed using co-culture system of transwell plates. We examined tumor tropism of MSC by Prussian blue staining and immunofluorescence. In vivo killing competence of MSCs carrying Adv-Stat3(-) toward breast tumor was analyzed by comparison of tumor volumes and survival periods. Results: Adv-Stat3(-) amplified in MSCs and were released 4 days after infection. MSCs carrying Adv-Stat3(-) caused viral amplification, depletion of Stat3 and its downstream proteins, and led to significant apoptosis in breast cancer and melanoma cell lines. In vivo experiments confirmed the preferential localization of MSCs in the tumor periphery 24 hours after tail vein injection, and this localization was mainly detected in the tumor parenchyma after 72 hours. Intravenous injection of MSCs carrying Adv-Stat3(-) suppressed the Stat3 pathway, down-regulated Ki67 expression, and recruited CD11b-positive cells in the local tumor, inhibiting tumor growth and increasing the survival of tumor-bearing mice. Conclusions: These results indicate that MSCs migrate to the tumor site in a time-dependent manner and could be an effective platform for the targeted delivery of CRAd and the amplification of tumor killing effects.

1 January 2021 in International Journal of Biological Sciences
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Journal Article
Open access
CCCan-Hui Cao
Can-Hui Cao
RLRang Liu
Rang Liu
XLXin-Ran Lin
Xin-Ran Lin
JLJia-Qi Luo
Jia-Qi Luo
LCLi-Juan Cao
Li-Juan Cao
Xia XiXia Xi
Xia Xi
Human papillomavirus (HPV) infection and gene mutations were reputed as key factors in cervical carcinoma (CC) and head and neck squamous cell carcinoma (HNSCC). However, the associations of HPV status and gene mutations remain to be determined. This study aims to identify molecular patterns of LRP1B mutation and HPV status via rewiring tumor samples of HNSCC (n=1478) and CC (n=178) from the TCGA dataset. Here, we found that LRP1B mutation was associated with HPV status in CC (P=0.040) and HNSCC (P=0.044), especially in HPV 16 integrated CC (P=0.036). Cancer survival analysis demonstrated that samples with LRP1B mutation showed poor disease outcomes in CC (P=0.013) and HNSCC (P=0.0124). In addition, the expression status of LPR1B was more favorable for prediction than TP53 or RB1 in CC and HNSCC. Mutation clustering analysis showed that samples with LRP1B mutation showed higher mutation count in CC (P=1.76e-67) and HNSCC (P<10e-10). Further analysis identified 289 co-occurrence genes in these two cancer types, which were enriched in PI3K signaling, cell division process, and chromosome segregation process, et al. The 289-co-occurrence gene signature identified a cluster of patients with a higher portion of copy number variation (CNV) lost in the genome, different tumor HPV status (P<10e-10), higher mutation count (P<10e-10), higher fraction genome altered value (P=2.078e-4), higher aneuploidy score (P=3.362e-4), and earlier started the smoking year (P=2.572e-4), which were associated with shorter overall survival (P=0.0103) in CC and HNSCC samples. Overall, LRP1B mutation was associated with tumor HPV status and was an unfavorable prognostic biomarker for CC and HNSCC.

15 April 2022 in Journal of Leather Science and Engineering
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Journal Article
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RLRang Liu
Rang Liu
MDMengyuan Dai
Mengyuan Dai
GGGuidong Gong
Guidong Gong
MCMei Chen
Mei Chen
CCCanhui Cao
Canhui Cao
Xia XiXia Xi
Xia Xi
Extracellular matrix (ECM) is characterized as widespread, abundant, and pluripotent. Among ECM members, collagen is widely accepted as one of the most prominent components for its essential structural property that can provide a scaffold for other components of ECM and the rich biological functions, which has been extensively used in tissue engineering. Emerging evidence has shown that the balance of ECM degradation and remodeling is vital to regulations of maternal–fetal interface including menstrual cycling, decidualization, embryo implantation and pregnancy maintenance. Moreover, disorders in these events may eventually lead to failure of pregnancy. Although the improvement of assisted conception and embryo culture technologies bring hope to many infertile couples, some unfavorable outcomes, such as recurrent implantation failure (RIF), recurrent pregnancy loss (RPL) or recurrent miscarriage (RM), keep troubling the clinicians and patients. Recently, in vitro three-dimensional (3D) model mimicking the microenvironment of the maternal–fetal interface is developed to investigate the physiological and pathological conditions of conception and pregnancy. The progress of this technology is based on clarifying the role of ECM in the endometrium and the interaction between endometrium and conceptus. Focusing on collagen, the present review summarized the degradation and regulation of ECM and its role in normal menstruation, endometrium receptivity and unsatisfying events occurring in infertility treatments, as well as the application in therapeutic approaches to improve pregnancy outcomes. More investigations about ECM focusing on the maternal–fetal interface interaction with mesenchymal stem cells or local immunoregulation may inspire new thoughts and advancements in the clinical application of infertility treatments.Graphical abstract

13 May 2020 in Reproductive Biology and Endocrinology
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Journal Article
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Xia XiXia Xi
Xia Xi
MBMartina S. Burn
Martina S. Burn
YCYong Chen
Yong Chen
CKCengiz Karakaya
Cengiz Karakaya
AKAmanda N. Kallen
Amanda N. Kallen
Context: The H19 long noncoding RNA (lncRNA) belongs to a highly conserved, imprinted gene cluster involved in embryonic development and growth control. We previously described a novel mechanism whereby the Anti-mullerian hormone (Amh)appears to be regulated byH19.However, the relationship between circulatingH19and markers of ovarian reserve including AMH not been investigated.Objective: To determine whetherH19expression is altered in women with decreased ovarian reserve.Design: Experimental study.Setting: Yale School of Medicine (New Haven, USA) and Gazi University School of Medicine (Ankara, Turkey).Patients or other participants: A total of 141 women undergoing infertility evaluation and treatment.Intervention: Collection of discarded blood samples and cumulus cells at the time of baseline infertility evaluation and transvaginal oocyte retrieval, respectively.Main outcome measure: Serum and cumulus cellH19expression.Results: Women with diminished ovarian reserve (as determined by AMH) had significantly lower serum H19 expression levels as compared to controls (p < 0.01). Serum H19 was moderately positively correlated with serum AMH. H19 expression was increased 3.7-fold in cumulus cells of IVF patients who demonstrated a high response to gonadotropins, compared to low responders (p < 0.05).Conclusion: In this study, we show that downregulation ofH19in serum and cumulus cells is closely associated with decreased ovarian reserve, as measured by decreased AMH levels and reduced oocyte yield at oocyte retrieval. Further study with expanded sample sizes is necessary to determine whetherH19may be of use as a novel biomarker for diminished ovarian reserve.

1 November 2019 in Medicine
Verified
Journal Article
Open access
JLJiaqi Luo
Jiaqi Luo
YSYu Shi
Yu Shi
DLDan Liu
Dan Liu
DYDanni Yang
Danni Yang
JWJiahui Wu
Jiahui Wu
Xia XiXia Xi
Xia Xi
Background: Salpingectomy is routinely performed in ectopic pregnancy (EP). However, the effect of the surgery on the ovarian reserve and ovarian response in EP patients is still uncertain and has not been systematically evaluated. Therefore, we conducted this meta-analysis to provide a comparison of the ovarian reserve and ovarian response between the pre-salpingectomy and post-salpingectomy in EP patients. Methods: Pubmed, Embase, and Cochrane Library were searched for all relevant articles published up to December 2018. We retrieved the basic information and data of the included studies. The data was analyzed by Review Manager 5.3 software (Cochrane Collaboration, Oxford, UK). Results: A total of 243 articles were extracted from the databases, and 7 studies were included in the meta-analysis. The ovarian reserve including anti-Mullerian hormone (inverse variance [IV] −0.7 [95% confidence interval [CI] −0.63, 0.49]), antral follicle count (IV 1.7 [95% CI −2.02, 5.42]) and basal follicle stimulating hormone (IV 0.02 [95% CI −0.63, 0.68]) was comparable between the pre-salpingectomy group and the post-salpingectomy group. The amount of gonadotropin was significantly higher in the post-salpingectomy group when compared with that in the pre-salpingectomy group (IV −212.65 [95% CI −383.59, −41.71]). There was no significant difference in the left parameters of the ovarian response including the duration of gonadotropin stimulation (IV −0.32 [95% CI −0.76, 0.12]), the estrogen level on the human chorionic gonadotropin triggering day (IV −4.12 [95% CI −236.27, −228.04]) and the number of retrieved oocytes (IV 0.35 [95% CI −0.76, 1.46]) between 2 groups. Conclusions: The current results suggest that salpingectomy has no negative effect on the ovarian reserve and ovarian response.