Biomedical subjects

Xiaoqing Guo

Publications and source records attributed to Xiaoqing Guo.

6 recordsLinked to original sources

PubMed2026

PDZ-binding kinase promotes ovarian cancer cell proliferation and invasion via CCNB1 regulation.

BACKGROUND: Ovarian cancer is one of the most lethal gynecological malignancies, characterized by late diagnosis, frequent recurrence, and high mortality. PDZ-binding kinase (PBK), a serine/threonine kinase of the mitogen-activated protein kinase kinase (MAPKK) family, has been implicated in the tumorigenesis of multiple cancers, yet its role in ovarian cancer remains incompletely characterized. This study aimed to investigate the effect of PBK on the proliferation and invasion of ovarian cancer cells. METHODS: The expression of PBK and cyclin B1 (CCNB1) in normal ovarian tissues and ovarian cancer tissues was analyzed using online databases including Gene Expression Profiling Interactive Analysis 2 (GEPIA2), Clinical Proteomic Tumor Analysis Consortium (CPTAC), and Kaplan-Meier Plotter. Clinical tissue specimens were collected to detect the expression of PBK and CCNB1 by immunohistochemistry. Quantitative real-time polymerase chain reaction (PCR) was performed to detect PBK messenger RNA (mRNA) expression levels in clinical specimens and cell lines. Western blot was used to detect PBK protein expression in ovarian cancer cell lines. ES2 and A2780 cells with higher PBK expression were selected to construct PBK knockdown cell lines using lentiviral interference vectors. Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EdU) assay were performed to explore the effect of PBK knockdown on cell proliferation. Transwell assay was used to investigate the effect on cell invasion. The Cancer Genome Atlas (TCGA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were utilized to analyze PBK-related pathways and predict CCNB1 as the gene most closely related to PBK. RESULTS: PBK was significantly overexpressed in ovarian cancer tissues and cell lines compared with normal controls, and high PBK expression was associated with poor overall survival (OS) and progression-free survival (PFS). Knockdown of PBK expression inhibited the proliferation, colony formation, and invasion of ovarian cancer cells. Bioinformatics analysis revealed that CCNB1 was significantly overexpressed in ovarian cancer and high CCNB1 expression was associated with poor OS. CCNB1 was also significantly highly expressed in ovarian cancer tissues as validated by immunohistochemistry and was associated with lymph node metastasis. PBK and CCNB1 expression showed a significant positive correlation in TCGA ovarian cancer datasets. Knockdown of PBK inhibited CCNB1 expression in ovarian cancer cells. CONCLUSIONS: PBK promotes ovarian cancer cell proliferation and invasion. PBK knockdown leads to CCNB1 downregulation. These findings suggest that CCNB1 contributes to PBK-mediated oncogenic effects and identify the PBK-CCNB1 axis as a potential therapeutic target for ovarian cancer treatment.

PDZ-binding kinase (PBK)↗

PubMed2006

Erythrocytosis in a scleroderma patient.

A 40-year-old black male with scleroderma lung disease presented with blurry vision and headache. His presenting hemoglobin was 22.3 g/dL and his serum erythropoietin level was surprisingly low. Although nocturnal hypoxemia was evident, his daytime resting arterial oxygen saturation was normal. The patient's symptoms of hyperviscosity improved after phlebotomy, as his hemoglobin gradually decreased to 18.3 g/dL. Repeat serum erythropoietin levels were in normal and high ranges. Patients with chronic interstitial lung disease and erythrocytosis could have normoxemia at rest and a normal or low serum erythropoietin level at the peak of erythrocytosis. A repeat sampling of serum erythropoietin and monitoring of oxygen saturation during sleep and exertion may help in diagnosis. Physicians should prescribe continuous oxygen therapy for patients with chronic interstitial lung disease and erythrocytosis, even if diurnal resting hypoxemia is absent.

Adult↗

PubMed2004

Transduction of functionally active TAT fusion proteins into cornea.

A technology has recently been developed that allows for the rapid transduction of full-length functionally active proteins into intact tissue through intravenous injection and into cultured cells. This technology involves the fusion of an 11 amino acid sequence of the HIV TAT protein to the protein of interest. In the current investigation, we determined whether functionally active TAT fusion proteins could be transduced into intact corneas by topical application. TAT-beta-galactosidase was purified from bacterial cells and applied in serial dilutions (12.5-250 nm) to cultured epithelial cells for 5 or 15 min. In addition, enucleated globes and excised corneas with or without a central 3-mm epithelial debridement were incubated with TAT-beta-galactosidase for 1 or 2 hr. Excised corneas were allowed to heal in organ culture. Transduction of active beta-galactosidase was detected by incubating the cells or corneas with X-gal. TAT-beta-galactosidase was transduced into nearly all cultured cells in a concentration-dependent manner. When TAT-beta-galactosidase was topically applied to intact corneas, only the most superficial layer of epithelium was highly transduced. When the superficial layer was removed with nitrocellulose, two to four layers of cells were transduced. In corneas with a central debridement, epithelial cells at the edge of the debridement were transduced as well as the stromal cells subjacent to the debridement. Active beta-galactosidase was maintained at least 1 day in organ culture. No X-gal reaction was seen in either cells or corneas not incubated with TAT-beta-galactosidase. Functionally active proteins can be efficiently transduced into corneal epithelial and stromal cells using TAT fusion protein technology. The intact epithelium provides a barrier to penetration of TAT proteins. This barrier can be overcome by disrupting the epithelium. TAT-mediated protein transduction may be extremely useful in studies of corneal wound healing and homeostasis.

Animals↗

PubMed2004

Cell cycle regulators at the ocular surface.

The ocular surface provides an outstanding model to examine the regulation of the proliferative cell cycle. Cells within the cornea and conjunctiva exhibit a wide range of proliferative abilities ranging from the rapidly proliferating cells in the basal cell layer of the epithelium to the quiescent keratocytes and endothelial cells. In this review, dedicated to Dr David Maurice, we will discuss four families of proteins known to regulate the cell cycle. These families include: (1) the cyclins; (2) the CIP/KIP family of cell cycle inhibitors--consisting of p21, p27, and p57; (3) the INK4 family of cell cycle inhibitors--including p16, p15, p18, and p19; and (4) the retinoblastoma family--consisting of pRb, p107, and p130. Members of all of these families have been localized in various cells in the ocular surface. We will discuss how these proteins are involved in regulating cell proliferation both in normal homeostasis and during wound healing.

Cell Cycle↗

PubMed2004

TAT-mediated protein transduction into human corneal epithelial cells: p15(INK4b) inhibits cell proliferation and stimulates cell migration.

PURPOSE: The cell cycle inhibitor p15(INK4b) has been localized in migrating corneal epithelial cells. In this study, TAT-fusion protein technology was used to transduce p15(INK4b) into human corneal epithelial cells to examine the effect on cell proliferation and migration. METHODS: Human p15(INK4b), obtained by RT-PCR, was cloned into a TAT-HA vector, and the fusion protein was purified from bacteria transformed with the TAT-HA-p15 construct. Various dilutions of TAT-HA-p15 were applied to primary human corneal epithelial cells to test potency. In addition, the effect of exposure time was examined. Cells were labeled with bromodeoxyuridine to detect proliferation, and indirect immunofluorescence was performed. Ki67 expression was also examined. To assay cell migration, human corneal epithelial cells were plated inside a cylinder and exposed to TAT-HA-p15. The cylinder was removed, the cells were allowed to spread for 2 days, and the area of cell coverage was calculated. TAT-HA-beta-galactosidase served as the control in all experiments. Finally, the extent of retinoblastoma protein phosphorylation was assayed by Western blot in cells cultured with and without TAT-HA-p15. RESULTS: TAT-HA-p15 was successfully transduced into primary human corneal epithelial cells. TAT-HA-p15 decreased proliferation in a concentration- and time-dependent manner. The migration assay showed that TAT-HA-p15 stimulated cell migration 1.8-fold. TAT-HA-beta-galactosidase had no effect on proliferation or migration. Finally, TAT-HA-p15 decreased the level of phosphorylated retinoblastoma protein by 4.9-fold. CONCLUSIONS: Active p15(INK4b) can be efficiently transduced into primary human corneal epithelial cells using TAT-fusion protein technology. p15(INK4b) appears to be sufficient to inhibit corneal epithelial cell proliferation and to stimulate cell migration.

Base Sequence↗

PubMed2002

How to prevent, recognize, and treat drug-induced nephrotoxicity.

Many drugs can injure the kidneys, but they cause renal injury via only a few common mechanisms. Many patients who develop renal injury after drug exposure have identifiable risk factors that could be modified or that should preclude the use of these drugs in the first place.

Acute Kidney Injury↗