Neutrophil gelatinase-associated lipocalin regulates intracellular accumulation of Rh123 in cancer cells.

Multidrug resistance (MDR) is a major problem facing patients with cancer. Although Neutrophil gelatinase-associated lipocalin (NGAL) is highly expressed in various cancers, the possible role of NGAL in MDR is still obscure. In this article, we evaluated the effect of NGAL on Rh123 accumulation in cancer cells. NGAL was first down-regulated by short hairpin RNA-mediated interference. In correlation with the reduced NGAL expression, intracellular Rh123 accumulation was significantly decreased. We finally observed that inhibiting both of the ERK1/2 and p38 MAPK could seriously down-regulate NGAL expression and also decrease the intracellular accumulation of Rh123, indicating that NGAL-mediated Rh123 accumulation is regulated by the phosphorylation of ERK1/2 and p38 MAPK. Pretreatment of MDA-MB-231 with NGAL recombinant protein and antibody had significant effects on the intracellular accumulation of Rh123, whereas little effect was observed in K562 cells treated with the same method, suggesting that NGAL was involved in the regulation of Rh123 accumulation in these two types of cancers, although different pathways. Here we provide new evidence that directly shows the possibility of small chemical substances Rh123 intracellular accumulation that is regulated by NGAL. These results suggest the possibility of NGAL involvement in drug transportation and cancer MDR formation, and indicate the potential of NGAL in cancer therapy.

Basilar dolichoectasia with intermural hematoma accompanied by cerebral microbleeds and white matter hyperintensities: A case report.

RATIONALE: The clinical manifestations of basilar dolichoectasia (BD) are variable. The diagnosis is based on imaging measurements. Digital subtraction angiography displays only the dilated vascular lumen and lacks visualization of the arterial wall. High-resolution Magnetic resonance imaging (MRI) can identify intramural hematoma; therefore, it may be more suitable for the imaging evaluation of BD. However, most of the existing literature pertaining to BD lacks vascular wall assessment. PATIENT CONCERNS: A 65-year-old Chinese man perceived weakness of the left upper and lower limb, double vision, dizziness, nausea, and vomiting was admitted to the emergency department. Fifteen years prior to this admission, he began taking levamlodipine besylate inconsistently for hypertension, but the level of blood pressure control was uncertain. The patient's father had a family history of hypertension. DIAGNOSES: An emergency axial computed tomography scan of the brain showed basilar artery (BA) dilation. Computed tomography angiography further indicated a maximum BA diameter of 38.94 mm. The length was >182 mm. MRI revealed acute infarctions of the right medulla oblongata and pons. Meanwhile, the patient had evidence of cerebral small vessel disease, including cerebral microbleeds and white matter hyperintensities. Whole-exome sequencing eliminated significant genetic variations consistent with clinical phenotypes. BD and intramural hematoma were further confirmed by high-resolution MRI of the arterial wall. INTERVENTIONS: Atorvastatin was admitted according to the results of the high-resolution MRI of the arterial wall. Benidipine hydrochloride was selected as a long-term anti-hypertensive drug. OUTCOMES: The patient had no symptoms of neurological damage during 3-month follow-up. LESSONS: Current evidence shows that BD has no obvious correlation with atherosclerosis. BA dissection and uncontrolled hypertension may be important factors in the progression of BD. BD-related stroke is likely to recur, and there are no standard secondary prevention measures. BD is often accompanied by cerebral microbleeds, and bleeding risk must be assessed during secondary prevention. When the BA diameter is greater than 10 mm, anti-platelet medication should be used with caution, blood pressure should be strictly controlled, and endovascular treatment should be considered.

[Early apoptosis of HL-60 cells induced by anti-CD44 McAb A3D8 inhibiting ERK1/2-upregulated Bim expression].

This study was aimed to investigate the effects of anti-CD44 mAb A3D8 on proliferation and apoptosis of AML cells, to explore the mechanism of ERK1/2 and Bim in this process. Effect of the anti-CD44 mAb A3D8 on the HL-60 cell proliferation was assayed with MTT method, the change of mitochondrial transmembrane potential of HL-60 cells was analyzed by flow cytometry. The mRNA expression of Bim was determined by real-time quantitative RT-PCR. Western blot was used to detect the protein expression of p-ERK1/2. The results showed that mAb A3D8 could remarkably inhibit the proliferation capacity of the HL-60 cells in a dosage- and time-dependent ways. The mitochondrial transmembrane potential in HL-60 cells treated with A3D8 (3.0 µg/ml) was significantly decreased as compared with the control cells. Furthermore, the mRNA expression of Bim was much higher than that in controls. Expression of the p-ERK was much lower than that of the controls. It is concluded that anti-CD44 mAb A3D8 can inhibit the proliferation and induce the apoptosis of HL-60 cells, mechanism of which is enhancing the expression of Bim via inhibiting p-ERK1/2.

[Reversal of multidrug resistance in HL-60, MSC and CD34(+) cells from umbilical cord blood by sustained intracellular acidification].

The aim of this study was to investigate the effect of intracellular acidification on accumulation of rhodamine 123 (rh123) in non-mature cells with none or low expression of multidrug resistance MDR1. The expression of MDR1 mRNA was detected by real-time quantitative RT-PCR. Confocal laser microscopy was used to determine the calibration curve of intracellular acidification (pHi). MTT assay was used to detect the cytotoxicity of intracellular acidification on HL-60, MSC and CD34(+) cells from umbilical cord blood. Flow cytometry was applied to measure the influence of intracellular acidification. The results indicated that the intracellular acidification had no obvious cytotoxicity on HL-60, MSC and CD34(+) cells. The acidification resulted in the increased rhodamine 123 accumulation in HL-60, MSC and CD34(+) cells without P-gp activity. Moreover, the more primitive cells, the less accumulation of intracellular Rh123 were observed. It is concluded that the intracellular acidification can reverse the MDR of HL-60, MSC and CD34(+) cells.

[Na(+)/H(+) exchanger 1 expression and its effect on apoptosis in K562 and HL-60 cells with DNA damage].

This study was aimed to investigate the expression of Na(+)/H(+) exchanger 1 (NHE1) in K562 and HL-60 cells undergoing DNA damage induced by etoposide and to elucidate the regulating mechanism. Real-time quantitative PCR (RQ-PCR) and Western blot methods were used to determine the expression of NHE1 in K562 cells after the treating with etoposide. Meanwhile, the flow cytometry was used to detect the apoptosis of leukemic cells. The luciferase reporter vector containing NHE1 promoter was constructed to measure relative luciferase activity after treating with different etoposide concentrations. The results showed that the mRNA and protein of NHE1 increased in accordance with apoptosis ratio in HL-60 cells after treated with etoposide (p < 0.05), but no such obvious increase in K562 cells. Treatment with NHE1 specific inhibitor could block etoposide induced alkalization and reduce the apoptosis ratio of HL-60 cells. The expression pattern and apoptosis alteration was not similar in K562 cells. Relative luciferase activity of reporter vector containing NHE1 promoter however increased in K562 cells after treated with etoposide. It is concluded that the expression of NHE1 is up-regulated in the process of apoptosis of HL-60 cells induced by etoposide and depends on the pHi increasing caused by NHE1 up-regulation which is not found in K562 cells although the transcriptional activity increased.