Chemical Synthesis, Efficacy, and Safety of Antimalarial Hybrid Drug Comprising of Sarcosine and Aniline Pharmacophores as Scaffolds

Malaria is a disease caused by protozoans transmitted to humans by infected female Anopheles mosquitoes. According to the WHO report of 2015, there were 214 million cases of malaria with 438,000 deaths worldwide. Ninety percent of world’s malaria cases occur in Africa, where the disease is recognized as a serious impediment to economic and social development. Despite advancement in malaria research, the disease continues to be a global problem, especially in developing countries. Currently, there is no effective vaccine for malaria control. In addition, although there are effective drugs for treatment of malaria, this could be lost to the drug resistance in different Plasmodium species. The most lethal form is caused by P. falciparum which has developed resistance to many chemotherapeutic agents and possibly to the current drugs of choice. Reducing the impact of malaria is a key to achieving the sustainable development goals which are geared toward combating the disease. Covalent bitherapy is a rational and logical way of drug design which entails joining a couple of molecules with individual intrinsic action into a unique agent, hence packaging dual activity into one hybrid. This suggests the need to develop new antimalarial drugs that are effective against malaria parasites based on the new mode of action, molecular targets, and chemical structures. In silico studies have shown that sarcosine is able to bind to unique plasmodia proteins (P. falciparum ATCase), whereas aniline can be a ligand to target protein (enoyl acyl carrier protein reductase), hence suppressing the progression of the disease. The main objective of this study was to synthesize and determine the efficacy and safety of antiplasmodial hybrid drug comprising the sarcosine and aniline derivative for management of plasmodial infections. The hybrid drug was synthesized by adding thionyl chloride to sarcosine to form acyl chloride which was then added to aniline to form sarcosine-aniline hybrid molecule. The IC50 of sarcosine-aniline hybrid was 44.80 ± 4.70 ng/ml compared with that of aniline derivative which was 22.86 ± 1.26 ng/ml. The IC50 of control drugs was 2.63 ± 0.38 ng/ml and 5.69 ± 0.39 ng/ml for artesunate and chloroquine, respectively. There was a significant difference between IC50 of sarcosine-aniline hybrid and aniline derivative (p<0.05). There was also a significant difference between sarcosine-aniline hybrid and standard drugs used to treat malaria including artesunate and chloroquine (p<0.05). The ED50 of sarcosine-aniline hybrid drug was 6.49 mg/kg compared with that of aniline derivative which was 3.61 mg/kg. The ED50 of control drugs was 3.56 mg/kg, 2.94 mg/kg, and 1.78 mg/kg for artesunate-aniline hybrid, artesunate, and chloroquine, respectively. There was a significant difference (p<0.05) between ED50 of sarcosine-aniline hybrid and both controls such as aniline derivative, artesunate, artesunate-aniline hybrid, and chloroquine. Cytotoxicity results revealed that sarcosine-aniline hybrid was safe to vero cells with a CC50 of 50.18 ± 3.53 μg/ml. Sarcosine-aniline hybrid was significantly less toxic compared with artesunate, chloroquine, and doxorubicin. Sarcosine-aniline hybrid was efficacious and safe to mice. Therefore, covalent bitherapy should be used in drug development for drug resistance mitigation.

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Chemical Synthesis, Efficacy and Safety of Antimalarial Hybrid Drug Comprising of Sarcosine and Aniline Pharmacophores as Scaffolds

10.20944/preprints201911.0104.v1 ◽

2019 ◽

Author(s):

Jean Baptiste Niyibizi ◽

Peter G. Kirira ◽

Francis T. Kimani ◽

Fiona Oyatsi ◽

Joseph K. Ng’ang’a

Keyword(s):

Drug Resistance ◽

Sustainable Development Goals ◽

Vero Cells ◽

Efficacy And Safety ◽

Hybrid Molecule ◽

Aniline Derivative ◽

The Sustainable Development ◽

Significant Difference ◽

Development Goals ◽

The Impact

Background: Reducing the impact of malaria is a key to achieving the sustainable development goals which are geared towards eradicating the disease. The main objective of this study was to synthesize, determine the efficacy and safety of antiplasmodial hybrid drug comprising of sarcosine and aniline derivative for management of plasmodial infections. Results: The hybrid drug was synthesized by adding thionyl chloride to sarcosine in order to form acyl chloride which was then added to aniline to form sarcosine-aniline hybrid molecule. The IC50 of sarcosine-aniline hybrid was 44.80 ± 4.70 ng/ml compared to that of aniline derivative which was 22.86 ± 1.26 ng/ml. The IC50 of control drugs were 2.63 ± 0.38 ng/ml, 5.69 ± 0.39 ng/ml for artesunate and chloroquine respectively. There was a significant difference between IC50 of sarcosine-aniline hybrid and aniline derivative (P<0.05). There was also a significant difference between sarcosine-aniline hybrid and standard drugs used to treat malaria including artesunate and chloroquine (P<0.05). The ED50 of sarcosine-aniline hybrid drug was 6.49mg/kg compared to that of aniline derivative which was 3.61mg/kg. The ED50 of control drugs were 3.56 mg/kg, 2.94mg/kg and 1.78 mg/kg for artesunate-aniline hybrid, artesunate and chloroquine respectively. There was a significant difference (P<0.05) between ED50 of sarcosine-aniline hybrid and both controls such as aniline derivative, artesunate, artesunate-aniline hybrid and chloroquine. Cytotoxicity results revealed that sarcosine-aniline hybrid was safe to vero cells with a CC50 of 50.18±3.53µg/ml. Sarcosine-aniline hybrid was significantly less toxic compared to artesunate, chloroquine and doxorubicin. Sarcosine-aniline hybrid was also safe to mice. Conclusion: Therefore, covalent bitherapy should be used in drug development for drug resistance mitigation.

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The Impact of IDH1 Mutation and MGMT Promoter Methylation on Recurrence-Free Interval in Glioblastoma Patients Treated With Radiotherapy and Chemotherapeutic Agents

Pathology & Oncology Research ◽

10.3389/pore.2021.1609778 ◽

2021 ◽

Vol 27 ◽

Author(s):

Maher Kurdi ◽

Nadeem Shafique Butt ◽

Saleh Baeesa ◽

Badrah Alghamdi ◽

Yazid Maghrabi ◽

...

Keyword(s):

Promoter Methylation ◽

Tumor Recurrence ◽

Dna Methyltransferase ◽

Chemotherapeutic Agents ◽

Idh1 Mutation ◽

Treatment Modalities ◽

Isocitrate Dehydrogenase 1 ◽

Free Interval ◽

Significant Difference ◽

The Impact

The aim of this study is to investigate the relationship between isocitrate dehydrogenase-1 (IDH1) mutation and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation with recurrence-free interval in glioblastoma patients treated with chemoradiotherapies. Clinical data were collected from 82 patients with totally resected glioblastoma and treated with adjuvant therapies from 2014 to 2019. IDH1 mutation was assessed by immunohistochemistry and MGMT promoter methylation was assessed by different sequencing methods. IDH1 mutation was present in 32 cases and 50 cases were IDH1 wildtype; 54 and 28 patients had unmethylated and methylated MGMT promoter, respectively, Of the 82 patients, 62 patients received chemoradiotherapy while 20 patients only received radiation. Approximately, 61% of patients had a tumor recurrence after 1 year, and 39% showed a recurrence before 1 year of treatment. There was no significant relationship between IDH1 mutation and MGMT promoter methylation (p-value = 0.972). Patients with IDH1 mutation and their age <50 years showed a significant difference in recurrence-free interval (p-value = 0.014). Difference in recurrence-free interval was also statistically observed in patients with unmethylated MGMT promoter and treated with chemoradiotherapies (p-value = 0.031), by which they showed a late tumor recurrence (p-value = 0.016). This revealed that IDH1 mutation and MGMT methylation are independent prognostic factors in glioblastoma. Although IDH1-mutant glioblastomas showed late tumor recurrence in patients less than 50 years old, the type of treatment modalities may not show additional beneficial outcome. Patients with unmethylated MGMT and IDH1 mutation, treated with different chemoradiotherapies, showed a late tumor recurrence.

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Impact of cytochrome P450 2C19 polymorphisms on the clinical efficacy and safety of voriconazole: an update systematic review and meta-analysis

10.22541/au.162546769.92188192/v1 ◽

2021 ◽

Author(s):

Ying Zhang ◽

Xu Hao ◽

Kelu Hou ◽

Lei Hu ◽

Jingyuan Shang ◽

...

Keyword(s):

Cytochrome P450 ◽

Adverse Events ◽

Success Rate ◽

Clinical Efficacy ◽

Search Algorithm ◽

Efficacy And Safety ◽

Increased Risk ◽

Significant Difference ◽

The Impact ◽

Cyp2c19 Polymorphisms

Aims: To assess the impact of cytochrome P450 (CYP) 2C19 polymorphisms on the clinical efficacy and safety of voriconazole. Methods: We systematically searched PubMed, EMBASE, CENTRAL, ClinicalTrials.gov, and three Chinese databases from their inception to March 18, 2021 using a predefined search algorithm to identify relevant studies. Studies that reported voriconazole-treated patients and information on CYP2C19 polymorphisms were included. The efficacy outcome was success rate. The safety outcomes included overall adverse events, hepatotoxicity and neurotoxicity. Results: A total of 20 studies were included. Intermediate metabolizers (IMs) and Poor metabolizers (PMs) were associated with increased success rates compared with normal metabolizers (NMs) (risk ratio (RR): 1.18, 95% confidence interval (CI): 1.03~1.34, I2=0%, p=0.02; RR: 1.28, 95%CI: 1.06~1.54, I2=0%, p=0.01). PMs were at increased risk of overall adverse events in comparison with NMs and IMs (RR: 2.18, 95%CI: 1.35~3.53, I2=0%, p=0.001; RR: 1.80, 95% CI: 1.23~2.64, I2=0%, p=0.003). PMs demonstrated a trend towards an increased incidence of hepatotoxicity when compared with NMs (RR: 1.60, 95%CI: 0.94~2.74, I2=27%, p=0.08), although there was no statistically significant difference. In addition, there was no significant association between CYP2C19 polymorphisms and neurotoxicity. Conclusions: IMs and PMs were at a significant higher success rate in comparison with NMs. PMs were significantly associated with an increased incidence of all adverse events compared with NMs and IMs. Researches are expected to further confirm these findings. Additionally, the relationship between hepatotoxicity and CYP2C19 polymorphisms deservers clinical attention.

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Effect of Endoscope Flexibility on Tissue Dissection Profile Assessed With Pulsed Water Jet Device: Ensuring Safety, Efficacy, and Handling of Thin Devices for Neuroendoscopic Surgery

10.21203/rs.3.rs-94399/v1 ◽

2020 ◽

Author(s):

Tetsuya Kusunoki ◽

Tomohiro Kawaguchi ◽

Atsuhiro Nakagawa ◽

Yuta Noguchi ◽

Shinichiro Osawa ◽

...

Keyword(s):

Water Jet ◽

Efficacy And Safety ◽

Neuroendoscopic Surgery ◽

Significant Difference ◽

Tissue Dissection ◽

Inner Diameter ◽

The Mean ◽

Pulsed Water Jet ◽

The Impact ◽

The Brain

Abstract Objective: We developed an actuator-driven pulsed water jet device (ADPJ) for flexible neuroendoscopy to achieve effective tissue dissection with vasculature preservation. Although flexibility is a strong advantage for minimally invasiveness, the effect of the ductile curvature on the dissection profiles remains unknown. The purpose of this study was to clarify the impact of the curvature change of the ADPJ connecting tube on the dissection safety and efficacy.Results: Three ADPJ connecting tubes with different inner diameters (1.0, 0.75, 0.5 mm) were used to dissect the brain phantom. They were bent at 3 angles: 0 °, 60 °, and 120 °. The dissection profiles were evaluated using the mean depth and coefficient of variation (CV) for efficacy and safety, respectively.The larger inner diameter connecting tube dissected more deeply. The dissection depth was not changed regardless of the curvature degree in each tube. There was no significant difference in CVs regardless of inner diameter and curvature. The ductile curvature of the flexible neuroendoscope did not affect the efficacy and safety of the ADPJ dissection profile. Among the numerous instruments, tube-formed devices, including suction and injecting devices such as ADPJ, can be used safely and effectively without flexibility-related limitations.

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Resistance at No Cost: The Transmissibility and Potential for Disease Progression of Drug-ResistantM. Tuberculosis

10.1101/475764 ◽

2018 ◽

Cited By ~ 2

Author(s):

Mercedes C. Becerra ◽

Chuan-Chin Huang ◽

Leonid Lecca ◽

Jaime Bayona ◽

Carmen Contreras ◽

...

Keyword(s):

Drug Resistance ◽

Drug Resistant ◽

Resistance Mutations ◽

Pulmonary Tb ◽

Genetic Fingerprint ◽

Resistant Tuberculosis ◽

Significant Difference ◽

Mdr Tb ◽

The Impact

AbstractBackgroundThe future trajectory of drug resistant tuberculosis strongly depends on the fitness costs of drug resistance mutations. Here, we measured the association of phenotypic drug resistance and the risk of TB infection and disease among household contacts (HHCs) of patients with pulmonary TB.MethodsWe evaluated 12767 HHCs of patients with drug sensitive and resistant pulmonary TB at baseline, two, six, and 12 months to ascertain infection status and to determine whether they developed tuberculosis disease. We also assessed the impact of drug resistance phenotype on the likelihood that a TB strain shared a genetic fingerprint with at least one other TB patient in the cohort.FindingsAmong 3339 TB patients for whom were DST available, 1274 (38%) had TB that was resistant to at least one drug and 478 (14⋅3%) had multi-drug resistant (MDR) TB, i.e. TB resistant to both INH and rifampicin. Compared to HHCs of drug sensitive TB patients, those exposed to a patient with MDR-TB had an 8% (95% CI: 4-13%) higher risk of infection by the end of follow up. We found no statistically significant difference in the relative hazard of incident TB disease among HHCs exposed to MDR-TB compared to DS-TB (Adjusted HR 1⋅28 [(95% CI: ⋅9-1⋅83]). Patients with MDR-TB were more likely to be part of a genetic cluster than were DS-TB patients.InterpretationClinical strains of MDR M. tuberculosis are neither less transmissible than drug sensitive strains nor less likely to cause disease. (ClinicalTrials.gov number,NCT00676754)FundingNational Institutes of Health: NIH/NIAID CETR U19AI109755StatementAll authors have seen the manuscript and approved the manuscript.

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The expression of pAKT/survivin and their role in colorectal cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.4_suppl.595 ◽

2018 ◽

Vol 36 (4_suppl) ◽

pp. 595-595

Author(s):

Junjie Gu ◽

Zhao Sun ◽

Chunmei Bai ◽

Fei Luo

Keyword(s):

Colorectal Cancer ◽

Drug Resistance ◽

Survivin Expression ◽

Progression Free Survival ◽

Chemotherapeutic Agents ◽

P Value ◽

Chi Square ◽

Free Survival ◽

Significant Difference ◽

Colorectal Cancer Patients

595 Background: Colorectal cancer(CRC) is the fourth most prevalent cancer and the leading cause of cancer mortality worldwide. Drug resistance remains the main obstacle to the success of cytotoxic therapies. It is reported that soluble factors released by carcinoma-associated fibroblasts(CAFs) can induce the translocation of AKT, Survivin, P38 to the nucleus of tumor cells, which might be the mechanism of microenvironment-mediated drug resistance to nonspecific conventional chemotherapeutic agents, such as platinum compounds or 5-FU. Methods: Clinicopathological data of colorectal cancer patients who underwent chemotherapy (XELOX or FOLFOX) were collected, followed up and evaluated. p-AKT and survivin expression were assessed by immunohistochemical (IHC) staining. The relationships between p-AKT and survivin expression and patients’ resistance to chemotherapy were analyzed by Chi square respectively. The expression between p-AKT and survivin expression and progression-free survival(PFS) of patients were analyzed by Kaplan-Meier. Results: 51 CRC patients were enrolled in our research. Among them, 21 patients were resistant to chemotherapy(PD), and 30 patients were sensitive to chemotherapy(PR). P-AKT and survivin were assessed by IHC in 47 patients. Among them, 17 patients were p-AKT positive, and 29 patients were survivin positive. Patients of progressive disease(resistant to chemotherapy) were significantly associated with p-AKT positive and survivin positive(p = 0.009, 0.000). Poorer progression-free survival(PFS) was observed in patients with survivin positive compared to those with survivin negative(6.323±0.9m, 13.857±2.664m, Breslow chi square = 4.885, p value = 0.027). There is no significant difference between p-AKT expression and PFS(Breslow chi square = 2.403, p value = 0.121). Conclusions: CRC patients with p-AKT positive or survivin positive were more likely to be resistant to chemotherapeutic agents. CRC patients with survivin positive had a shorter DFS.

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Monotherapy for Low-Risk Gestational Trophoblastic Neoplasia with score 5-6

10.21203/rs.3.rs-1110494/v1 ◽

2021 ◽

Author(s):

Li Kemin ◽

Zhang Mengpei ◽

Yin Rutie ◽

Li Zhengyu

Keyword(s):

Drug Resistance ◽

Combination Chemotherapy ◽

Prognostic Score ◽

Single Agent ◽

Low Risk ◽

Gestational Trophoblastic Neoplasia ◽

Efficacy And Safety ◽

Significant Difference ◽

Β Hcg ◽

Single Agent Chemotherapy

Abstract Objective To investigate efficacy and safety of monotherapy in low-risk gestational trophoblastic neoplasia (GTN) patients with a high FIGO/WHO prognostic score of 5–6. Methods The low-risk GTN patients with a high FIGO/WHO prognostic score of 5–6 from January 2012 to December 2019 were enrolled. The study is a retrospective report. Real-world data were used to analyze the efficacy and safety of single-agent chemotherapy and combination chemotherapy in patients with a high FIGO/WHO prognostic score of 5–6. Results A total of 224 patients were enrolled, including 75 cases (33.5%) with a FIGO/WHO prognostic score of 5–6. Complete remission was in all patients. Among the 29 cases with a FIGO/WHO prognostic score of 5–6 taking single-agent chemotherapy, 22 cases (75.9%) developed drug resistance, the number of chemotherapy courses was 7.8±2.1, and the number of chemotherapy courses required for β-hCG to return to normal was 5.4±1.8. Among the 46 cases taking combination chemotherapy, 7 patients (15.2%) developed drug resistance, the number of chemotherapy courses was 7.4±2.0, and the number of chemotherapy courses required for β-hCG to return to normal was 4.8±1.6. There was a statistically significant difference in the drug resistance rate between these two subgroups (P < 0.05), but there was not statistically significant difference in the total number of chemotherapy courses or number of chemotherapy courses required for β-hCG to return to normal (<2mIU/ml) (P < 0.05). Conclusion Monotherapy showed remarkable advantages in low-risk GTN patients with a FIGO/WHO prognostic score of 5–6.

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An In Silico Study of a Novel rpoB Insertion in a Cluster of Clinical Strains of Mycobacterium tuberculosis Highly-Rifampicin Resistant

10.20944/preprints201707.0078.v1 ◽

2017 ◽

Author(s):

Maria Lucia R. Rossetti ◽

Pedro Almeida da Silva ◽

Raquel Maschmann ◽

Andrea von Groll ◽

Leonardo S. Esteves ◽

...

Keyword(s):

Drug Resistance ◽

Virtual Screening ◽

Rna Polymerase ◽

In Silico ◽

Chemotherapeutic Agents ◽

Single Amino Acid ◽

Mutant Form ◽

Clinical Strains ◽

In Silico Studies ◽

Biological Cost

Rifampicin is one of the most important chemotherapeutic agents used in the treatment of tuberculosis. M. tuberculosis clinical strains resistant to rifampicin harbor mainly mutation in an 81-base pair region of rpoB. These mutations mainly consist of single amino acid substitutions. However insertions also can be related with rifampicin resistance strains. Herein, we described an insertion of 12 nucleotides in clinical isolates of M. tuberculosis resistant to rifampicin, all obtained from inmates. To evaluate the importance this insertion in surviving and drug resistance, it were carried out fitness experimental assays as well as in silico studies of 3D structural models, molecular docking simulations and virtual screening. The medical records of the seven patients showed all were previously treated to tuberculosis. Growth curves shown that the insertion determines a biological cost when compared to wild type rpoB and katG; or the double mutated rpoB S531L and katG S315T. From docking and molecular dynamics simulations it can be inferred that the insertion does not affect the process of synthesis of RNA transcripts. On the other hand, in the mutant RNAP-RIF complex rifampicin confirmed a low affinity interaction for the mutant form. Interesting, virtual screening for potential inhibitors for wtRNAP and mRNAP using a library of 1446 compounds approved by the FDA showed that the best ligands were mainly compounds with antibiotic activity, although the targets involved in the pharmacological action are other than RNAP. In conclusion, seven strains of M. tuberculosis RIF resistant that present an insertion of four amino acids in RNA polymerase showed by growth curve assays, a biological cost. Further, bioinformatics tools had characterized the putative drug resistance dynamic as well as the maintenance of RNA polymerase activity.

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What if Bevacizumab was discontinued! Can IMpower130 be exchanged for IMpower150 for advanced non-squamous NSCLC patients with PD-L1 <50% and without genomic mutations?

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.11.2.0398 ◽

2021 ◽

Vol 11 (2) ◽

pp. 291-297

Author(s):

Khaled Elmahdi Omran

Keyword(s):

Clinical Trials ◽

Immune Checkpoint ◽

Immune Checkpoint Inhibitor ◽

Checkpoint Inhibitor ◽

Checkpoint Inhibitors ◽

Single Agent ◽

Chemotherapeutic Agents ◽

Significant Difference ◽

Nsclc Patients ◽

The Impact

There was a radical change in the first-line management of advanced NSCLC with negative genetic oncological drive in the last 5 years. Immune checkpoint inhibition is currently recommended for such a group of patients by major international guidelines devoted to lung cancer, as long as there is no contraindication. The recommendations came as a single agent of immune checkpoint inhibitor, combination of an immune checkpoint inhibitor with chemotherapy with an optional anti-angiogenic agent, or combination between two different immune checkpoint inhibitors; based on the level of expression of programmed death-ligand 1 in the tumour microenvironment and the type of immune checkpoint inhibitor is intended to be used. IMpower150 was a clinical trial that illustrated the effectiveness of the addition of Atezolizumab (immune checkpoint inhibitor) to chemotherapy and Bevacizumab (anti-angiogenic agent) in treatment naïve advanced non-squamous NSCLC patients with no genetic aberrations. In the same trial, there was no significant difference between chemotherapy plus either Atezolizumab or Bevacizumab. Moreover, Atezolizumab experienced other disappointing results in different clinical trials in NSCLC and other malignancies such as triple-negative breast cancer when combined with chemotherapeutic agents that require corticosteroids as pre-medications during therapy. This review evaluates the synergistic anti-neoplastic effect of immune checkpoint inhibitor and anti-angiogenic agent in NSCLC which presented in IMpower150 by Atezolizumab and Bevacizumab, especially this combination is the preferred option for other malignancies such as hepatocellular carcinoma and renal cell carcinoma. Additionally, the review overlooks the impact of corticosteroids on Atezolizumab in different clinical trials, particularly in NSCLC.

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Galectin-3 Is the Molecular Target for Overcoming Multidrug Resistance Due to the Cell Protection by Bone Marrow Leukemia Microenvironment in Chronic Myeloid Leukemia,

Blood ◽

10.1182/blood.v118.21.3746.3746 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3746-3746

Author(s):

Mio Yamamoto ◽

Junya Kuroda ◽

Tsutomu Kobayashi ◽

Nana Sasaki ◽

Hisao Nagoshi ◽

...

Keyword(s):

Bone Marrow ◽

Drug Resistance ◽

Cell Death ◽

Chronic Myeloid Leukemia ◽

Cell Lines ◽

Myeloid Leukemia ◽

Chemotherapeutic Agents ◽

Leukemic Cells ◽

Galectin 3 ◽

The Impact

Abstract Abstract 3746 Recent advances in molecular targeted therapy using tyrosine kinase (TK) inhibitors (TKIs) for Bcr-Abl TK have greatly improved treatment outcomes for chronic myeloid leukemia (CML). However, complete elimination of CML clones has been rarely achieved by TKIs due to both intrinsic and extrinsic cell mechanisms. In this study, we investigated the molecular mechanisms for bone marrow microenvironment (BMME)-mediated leukemia progression and drug resistance in CML. CML cell lines MYL and K562 acquired drug resistance to imatinib mesylate (IM), dasatinib (Das), doxorubicin (DOX), cytarabine (CA), etoposide (VP16), or vincristine (VCR) through co-culture with HS-5, an immortalized human bone marrow stromal cell (BMSC)-derived cell line. We used microarray-based assays to investigate the changes in gene expression profiles in Philadelphia (Ph)-positive MYL as a result of co-culture with HS-5 and of adhesion to fibronectin (FN). In MYL with HS-5 or with FN, 902 and 910 genes, respectively, were upregulated more than 2.0-fold compared with control. Among the 284 genes commonly upregulated in MYL with HS-5 and with FN, we focused on galectin-3 (Gal-3) as one of the candidate mediators of BMME-mediated leukemia progression because of its pleiotropic cellular function. The levels of galectin-3 mRNA increased 3.84-fold as a result of co-culture with HS-5, and 2.83-fold as a result of adhesion to FN in MYL. The induction of Gal-3 by the co-culture with HS-5 or the adhesion to FN was also confirmed at the protein level, not only in MYL, but also in all Ph+ leukemic cell lines examined (K562, KBM5, KCL22, BV173), while Gal-3 protein expression was either absent or extremely low in normal liquid culture. To investigate the clinical significance of Gal-3 in CML, we examined its expression in BM-derived primary CML cells. Approval was obtained from the institutional review board at Kyoto Prefectural University of Medicine for a study using patient-derived samples, and the study was conducted in accordance with the ethical principles of the Declaration of Helsinki. Of the leukemic cells of 20 CML patients, those of all but one CML-blast crisis phase patient were positive for Gal-3. Ph+ cells from the CML-chronic phase were especially highly positive for Gal-3. In contrast, the frequency of Gal-3-positive cells from most acute leukemia patients was as low as that of BM hematopoietic cells from healthy volunteers. These results suggest that in the clinical setting Gal-3 expression in the BM milieu is more predominant in CML. To further characterize the role of Gal-3 in CML, Gal-3 overexpressing subcell lines of MYL and K562 were generated by transfection of pEF1Galec3.neo plasmid and designated as MYL/G3 and K562/G3, respectively. Gal-3 overexpression was found to confer moderately higher in vitro proliferation potency in medium containing 10% FCS as well as in low nutrient 1% FCS-containing medium compared with the cells transfected with the mock plasmid. We also examined the impact of Gal-3 overexpression on cell death induced by chemotherapeutic agents. Both MYL/G3 and K562/G3 were less sensitive than their parental cells to cell death induced by chemotherapeutic agents. This diminished sensitivity to cell death caused by chemotherapeutic agents was due to a reduction in apoptosis, as reflected by the reduced frequency of subG1 populations detected in DNA content analyses (FACS SubG1 analysis of results for 48-hour treatment: MYL 54.9%, MYL/G3 15.7% with IM 0.25uM; MYL 47.1%, MYL/G3 23.1% with Das 1.0nM; MYL 40.2%; MYL/G3 13.4% with DOX 200nM; MYL 45.7%; MYL/G3 19.4% with CA 150nM; MYL 50.9%; MYL/G3 19.1% with VP16 4uM; MYL 75.0%; MYL/G3 49.5% with VCR 8nM). We next examined the effect of an inhibitor for Gal-3, fractionated citrus pectin powder (FPP), on MYL and MYL/G3. As expected, MYL and MYL/G3 showed similar sensitivity to cell death induced by FPP, while the addition of FPP overcame resistance to IM-induced cell death in MYL/G3. Furthermore, the addition of FPP was found to have overcome HS-5-induced resistance against IM in MYL. Molecular sequelae of Gal-3 overexpression in leukemic cells were also investigated. Both co-culture with HS-5 and Gal-3 overexpression activated Akt and Erk, induced accumulation of Mcl-1 in MYL and K562. Collectively, our study disclosed that leukemia microenvironment-specific Gal-3 may be a candidate therapeutic target to help overcome BMME-mediated therapeutic resistance in CML. Disclosures: No relevant conflicts of interest to declare.

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