Concentrations Of L-OHP Research Articles

High concentration of oxaliplatin may be a risk factor for vascular pain.

Oxaliplatin (L-OHP) is an antineoplastic agent that frequently causes vascular pain. However, the risk factors for vascular pain are unclear, and prevention methods have not been established. We retrospectively investigated patients who were treated with L-OHP to examine the influence of patient characteristics and concomitant analgesic use on the incidence of vascular pain. We collected information about the presence or absence of vascular pain, age, sex, treatment dose and analgesic use of patients who received L-OHP at Tokyo Medical University Hachioji Medical Center. We analysed the relevance of each factor between the vascular pain onset and non-onset groups. Thirty-two patients (average age: 68.6years; 69.8% and 30.2% men and women, respectively) were classified into the vascular pain onset (n=64) and non-onset groups (n=68). The multivariate logistic regression analysis revealed that L-OHP concentration (>358.5mg/L) was an independent determinant of vascular pain development (odds ratio: 2.422, 95% CI: 1.117-5.252). Intergroup differences in age, sex, body mass index, non-steroidal anti-inflammatory drug use, and underlying pain from cancer and other comorbidities were not significant. High L-OHP concentration was identified as a significant risk factor for L-OHP-induced vascular pain. Our results indicate that the dilution of L-OHP may reduce the incidence of vascular pain.

Effect of intact oxaliplatin in plasma on a cold allodynia after multiple administrations in colorectal cancer model rats

Oxaliplatin (L-OHP)-induced acute neuropathy is a major factor for influencing treatment compliance in patients receiving chemotherapy for colorectal cancer (CRC). Acute neuropathy is caused by the intact L-OHP affecting the function of transient receptor potential vanilloid 1 (TRPV1) channel. In this study, the effectiveness of the detection of the intact L-OHP and the association with the severity of L-OHP-induced acute neuropathy were investigated using a rat model of CRC. Wistar male rats were prepared as models of CRC by using 1,2-dimethylhydrazine (DMH) and dextran sulfate. Intravenous L-OHP was administered (weekly) to CRC rats for 4 weeks, at doses of 3, 5, or 8 mg/kg, respectively. Pharmacokinetic and tumor distribution profiles of animals with intact L-OHP were observed on days 1 and 22. Cold allodynia was determined as a read-out of acute neuropathy using the acetone test over the 4 weeks. The mean AUC0-∞ values for the intact L-OHP were increased dose-dependently at the three doses. The accumulation of intact L-OHP was confirmed following an increase in L-OHP concentration on day 22. Acute neuropathy was observed from day 2 at all doses and the withdrawal response correlated with AUC (R2 =0.9816). To prevent the onset of L-OHP-induced acute neuropathy, the timely detection of the intact L-OHP is important. These findings could be a basis of the establishment a pharmacokinetic and toxicodynamic model to aid the planning of therapy cycle completion for CRC.

MiR-200b-3p mitigates oxaliplatin resistance via targeting TUBB3 in colorectal cancer.

Numerous abnormally expressed miRs have been reported involved in oxaliplatin (L-OHP) resistance of colorectal cancer (CRC). The present study aimed to investigate whether miR-200b-3p could regulate L-OHP resistance via targeting TUBB3 in CRC cells. L-OHP resistant HT29 and HCT116 cells were exposed to escalating concentrations of L-OHP up to 30 μm. The effect of miR-200b-3p on L-OHP resistant CRC cells was then evaluated using the cell counting kit-8 (CCK-8) assay. CRC cell apoptosis was detected using Annexin V-FITC/PI double staining. Bioinformatics algorithms and luciferase reporter assays were also performed to investigate whether TUBB3 was a direct target of miR-200b-3p. miR-200b-3p declined in L-OHP resistant CRC tissues and cell lines, and the overexpression of miR-200b-3p elevated the L-OHP sensitivity in L-OHP resistant HT29 and HCT116 cells. In addition, we determined the potential mechanisms underlying miR-200b-3p-mediated reversal of L-OHP resistance by mediating its downstream target TUBB3, and the overexpression of miR-200b-3p could induce migration and growth inhibition and apoptosis in L-OHP resistant HT29 and HCT116 cells by silencing βIII-tubulin protein expression. However, the overexpression of TUBB3 reversed miR-200b-3p mimic-induced migration, as well as growth inhibition and apoptosis, in L-OHP resistant CRC cells. miR-200b-3p improved L-OHP resistance and induced growth inhibition and cell apoptosis in L-OHP resistant CRC cells, and the underlying mechanism was mediated, at least partially, through the suppression of βIII-tubulin protein expression.

Semi-Mechanism-Based Pharmacokinetic-Toxicodynamic Model of Oxaliplatin-Induced Acute and Chronic Neuropathy.

Oxaliplatin (L-OHP) is widely prescribed for treating gastroenterological cancer. L-OHP-induced peripheral neuropathy is a critical toxic effect that limits the dosage of L-OHP. An ideal chemotherapeutic strategy that does not result in severe peripheral neuropathy but confers high anticancer efficacy has not been established. To establish an optimal evidence-based dosing regimen, a pharmacokinetic-toxicodynamic (PK-TD) model that can characterize the relationship between drug administration regimen and L-OHP-induced peripheral neuropathy is required. We developed a PK-TD model of L-OHP for peripheral neuropathy using Phoenix® NLME™ Version 8.1. Plasma concentration of L-OHP, the number of withdrawal responses in the acetone test, and the threshold value in the von Frey test following 3, 5, or 8 mg/kg L-OHP administration were used. The PK-TD model consisting of an indirect response model and a transit compartment model adequately described and simulated time-course alterations of onset and grade of L-OHP-induced cold and mechanical allodynia. The results of model analysis suggested that individual fluctuation of plasma L-OHP concentration might be a more important factor for individual variability of neuropathy than cell sensitivity to L-OHP. The current PK-TD model might contribute to investigation and establishment of an optimal dosing strategy that can reduce L-OHP-induced neuropathy.

Taxol-Resistant Gene 1 (Txr1) Mediates Oxaliplatin Resistance by Inducing Autophagy in Human Nasopharyngeal Carcinoma Cells.

BackgroundOxaliplatin (L-OHP) is an important chemotherapy regimen for nasopharyngeal carcinoma (NPC), but can fail due to drug resistance. In this study, the role of Txr1 (taxol-resistant gene 1) in oxaliplatin resistance was investigated.Material/MethodsCell viability assay was carried out using the CellTiter-Glo Luminescent Cell Viability Assay Kit. CNE1 and CNE2 cells were cultured continuously with gradually increasing concentrations of L-OHP for 6 months to establish drug-resistant cell lines. Autophagy was detected by electron microscopy. Txr1 expression in NPC cells was detected via Western blotting and real-time quantitative PCR (qRT-PCR).ResultsIn L-OHP-resistant CNE1/L-OHP and CNE2/L-OHP cells, mRNA and protein expression of Txr1 increased compared to the parental cells, and downregulation of Txr1 re-sensitized drug-resistant cells to L-OHP. Moreover, we found that Txr1-mediated L-OHP resistance was associated with increased autophagy. Txr1-overexpression cells developed L-OHP resistance and a high level of autophagy. Inhibiting autophagy using 2 different methods – inhibition of autophagy-related gene expression and autophagy inhibitor – attenuated L-OHP resistance of NPC cells.ConclusionsWe conclude that the detection of Txr1 might become a good indicator to evaluate the treatment and prognosis of nasopharyngeal carcinoma. Our data suggest that further investigation of Txr1 in the setting of L-OHP resistance is warranted.

Knockdown of ADAM17 inhibits cell proliferation and increases oxaliplatin sensitivity in HCT-8 colorectal cancer through EGFR-PI3K-AKT activation

We investigated the role of a disintegrin and metalloproteinase 17 (ADAM17) in chemo resistance, and to clarify the mechanism underlying reverse of L-OHP resistance by knockdown of ADAM17. CRC tissues with corresponding adjacent normal tissues were collected. The mRNA and protein expression of ADAM17 in tissues were detected by RT-qPCR, immunohistochemistry and Western blot. The prognostic impact of ADAM17 expression were then validated in TCGA database to confirm the results. Resistance to oxaliplatin was induced in HCT-8 (HCT-8/L-OHP) colorectal cancer cell line by exposing cell to increasing concentrations of L-OHP. MTT were used to evaluate the resistance to L-OHP. Subsequently, Knockdown of ADAM17 in HCT-8 and HCT-8/L-OHP cells to explore the mechanism through which ADAM17 shRNA reverses L-OHP resistance. Our result showed that ADAM17 was higher expression in the cancerous tissue and related to the chemosensitivity. Moreover, ADAM17 shRNA, AG1478 and LY294002 could inhibit cell proliferation, induce apoptosis and increase oxaliplatin sensitivity in HCT-8/L-OHP and parental colorectal cancer cell line, but nonsense shRNA did not show this effect. Western blot analysis further confirmed that EGFR/PI3K/AKT signaling pathway is involved in ADAM17 shRNA inhibiting proliferation and chemosensitivity of HCT-8/L-OHP and HCT-8 cells. The present study provides the evidence that downregulation of ADAM17 could increase the sensitivity to chemotherapy, inhibit cell proliferation, induce apoptosis, and reverse oxaliplatin resistance via suppression of the EGFR/PI3K/AKT signaling pathway in CRC.

Gambogic acid reverses oxaliplatin resistance in colorectal cancer by increasing intracellular platinum levels.

Resistance to oxaliplatin (L-OHP) is a major obstacle to successful chemotherapy in colorectal cancer (CRC). In the present study, the ability of gambogic acid (GA) to reverse L-OHP resistance in CRC LoVo cells was investigated. L-OHP-resistant LoVo/L-OHP cells were established by exposing them to increasing concentrations of L-OHP. GA-reversed L-OHP-sensitive LoVo/L-OHP/GA cells were established by exposure to 0.5 µmol/l GA for 2 weeks. A Cell Counting Kit-8 assay was used to assess levels of proliferation. Flow cytometry was applied to detect apoptosis rates. Transwell assays were used to analyse invasion. Inductively coupled plasma mass spectrometry was used to determine intracellular platinum (Pt) content. Western blot analysis was used to reveal the protein levels of Human copper transporter 1 (hCTR1), Copper-transporting p-type adenosine triphosphatases 1 (ATP7A) and Copper-transporting p-type adenosine triphosphatases 2 (ATP7B). LoVo/L-OHP and LoVo/L-OHP/GA cell lines were successfully established, and it was identified that L-OHP inhibited the proliferation of LoVo, LoVo/L-OHP and LoVo/L-OHP/GA cells in a dose-dependent manner. Compared with the parent LoVo cells, the anti-apoptosis and invasion properties of LoVo/L-OHP cells were enhanced, and were reversed by GA treatment. Intracellular Pt content was highest in the LoVo cells, followed by LoVo/L-OHP/GA cells, and then lowest in the LoVo/L-OHP cells. Downregulated hCTP1 and upregulated ATP7A and ATP7B were associated with L-OHP resistance, and GA reversed the resistance by increasing levels of hCTR1 and decreasing levels of ATP7A and ATP7B. In conclusion, GA has the potential ability to reverse L-OHP resistance in CRC cells by increasing intracellular Pt content, which it achieves by increasing hCTR1 levels and decreasing ATP7A and ATP7B levels. GA may represent a promising treatment agent for L-OHP resistance.

Knockdown of KLK11 reverses oxaliplatin resistance by inhibiting proliferation and activating apoptosis via suppressing the PI3K/AKT signal pathway in colorectal cancer cell.

IntroductionKallikrein 11 (KLK11) plays a crucial role in drug-resistance to oxaliplatin (L-OHP) in the treatment of metastatic colorectal cancer (mCRC). The study aimed to investigate the role of KLK11 in chemoresistance, and to clarify the mechanism underlying reverse of L-OHP resistance by knockdown of KLK11.Materials and MethodsResistance to oxaliplatin was induced in HCT-8 (HCT-8/L-OHP) colorectal adenocarcinoma cell lines by exposing cells to increasing concentrations of L-OHP. MTT, RT-qPCR, and Western blot were used to evaluate the resistance to L-OHP. We then knocked down KLK11 in HCT-8/L-OHP cells to explore the mechanism through which KLK11 reverses L-OHP resistance. The mRNA and protein expression of KLK11 in tissues from mCRC patients were detected by RT-qPCR and immunohistochemistry.ResultsThe drug resistance index (RI) of HCT-8/L-OHP cell line to L-OHP, 5-Fluorouracil (5-FU), Irinotecan (CPT-11), Vincristine (VCR) and Cis-diamminedichloroplatinum (CDDP) were 10, 5.35, 3.23, 1.28, and 6.64, respectively. Increased expression of multi-drug resistant genes ABCC1, ABCB1, GSTP1 and ERCC1 were detected in HCT-8/L-OHP cell line. Moreover, the activated PI3K/AKT pathway was related to L-OHP-resistance. Knockdown of KLK11 in HCT-8/L-OHP cell reversed L-OHP-resistance by inhibiting cell growth and activating apoptosis via suppressing the PI3K/AKT signaling pathway. Moreover, high expression of KLK11 in chemoresistant-patients was associated with lymph node metastases and histopathology.ConclusionKLK11 was highly expressed in chemoresistant-patients and L-OHP-resistant cell lines. Moreover, L-OHP resistance was associated with activated PI3K/AKT signal pathway. Knockdown of KLK11 can reverse L-OHP resistance by blocking PI3K/AKT signaling pathway.

Organic cation transporter 6 directly confers resistance to anticancer platinum drugs.

Organic cation transporters (OCTs) of the solute carrier family 22 have a critical role in the cellular uptake of anticancer platinum drugs. Recently, we found that a decreased OCT6 expression is associated with a reduced intracellular uptake of cisplatin (CDDP), and concomitant resistance to CDDP. In the present study, we examined whether OCTs directly confer resistance to another platinum drug, oxaliplatin (L-OHP). To address this, we used parental lung cancer cell lines, PC-14 and SBC3; L-OHP-resistant sublines, PC-14/L-OHP and SBC3/L-OHP; and one CDDP-resistant subline PC-14/CDDP, to examine the relationships between the expression of OCTs and intracellular platinum drug concentration or platinum drug resistance. The two L-OHP-resistant sublines showed cross resistance to CDDP and L-OHP, and a decreased expression of OCT6. The intracellular accumulation of L-OHP in PC-14/L-OHP cells was reduced compared with the parental cells. The findings suggested that a reduced OCT6 expression confers platinum drug resistance in the sublines by decreasing the uptake of platinum drugs. Using the PC-14/CDDP cell line engineered to overexpress OCT6, we confirmed that the intracellular L-OHP concentration was increased concomitantly with OCT6 overexpression compared with the parental cell line. Additionally, OCT6 was expressed in a screening panel of lung and colon cancer tissues and matched normal control tissues. Taken together with the previous results, the present findings indicate that OCT6 is directly involved in platinum drug resistance by mediating platinum drug uptake in cancer cells.

Effective anti-tumor activity of oxaliplatin encapsulated in transferrin–PEG-liposome

Oxaliplatin ( trans- l-diaminocyclohexane oxalatoplatinum, l-OHP) is a novel cisplatin derivative that can improve the side effects of cisplatin such as toxicity to the kidneys and peripheral nerve system. However, l-OHP is effective only when combined with 5-Fluorouracil (5-FU) and Leucovorin. The relatively low anti-tumor index of l-OHP alone is because low levels accumulate in tumor tissues due to high partitioning to erythrocytes in vivo. A successful outcome of cancer therapy using l-OHP requires the selective delivery of a relatively high concentration of the drug to tumors. The present study examines tumor-selective delivery of l-OHP using liposomes modified with transferrin-conjugated polyethyleneglycol (TF–PEG-liposomes). Delivery using these liposomes significantly reduced l-OHP partitioning to erythrocytes and improved the circulation time of l-OHP in vivo, resulting in enhanced extravasation of liposomes into tumors. The TF–PEG-liposomes maintained a high l-OHP concentration in tumors for over 72 h after intravenous injection, which was longer than that of the liposomes modified with PEG (PEG-liposomes). Intravenously administered l-OHP encapsulated within TF–PEG-liposomes ( l-OHP: 5 mg/kg) suppressed tumor growth more effectively than PEG-liposomes, Bare-liposomes and free l-OHP. Although l-OHP is usually combined with 5-FU and Leucovorin, our results suggest that l-OHP encapsulated within TF–PEG-liposomes has potential for cancer therapy.