Highly efficient novel recombinant L-asparaginase with no glutaminase activity from a new halo-thermotolerant Bacillus strain

Preclinical evaluation of engineered L-asparaginase variants to improve the treatment of Acute Lymphoblastic Leukemia

INTRODUCTION

Escherichia coli l-asparaginase (EcA), an integral part of multi-agent chemotherapy protocols of acute lymphoblastic leukemia (ALL), is constrained by safety concerns and the development of anti-asparaginase antibodies. Novel variants with better pharmacological properties are desirable.

METHODS

Thousands of novel EcA variants were constructed using protein engineering approach. After preliminary screening, two mutants, KHY-17 and KHYW-17 were selected for further development. The variants were characterized for asparaginase activity, glutaminase activity, cytotoxicity and antigenicity in vitro. Immunogenicity, pharmacokinetics, safety and efficacy were tested in vivo. Binding of the variants to pre-existing antibodies in primary and relapsed ALL patients' samples was evaluated.

RESULTS

Both variants showed similar asparaginase activity but approximately 24-fold reduced glutaminase activity compared to wild-type EcA (WT). Cytotoxicity against Reh cells was significantly higher with the mutants, although not toxic to human PBMCs than WT. The mutants showed approximately 3-fold lower IgG and IgM production compared to WT. Pharmacokinetic study in BALB/c mice showed longer half-life of the mutants (KHY-17- 267.28±9.74; KHYW-17- 167.41±14.4) compared to WT (103.24±18). Single and repeat-doses showed no toxicity up to 2000 IU/kg and 1600 IU/kg respectively. Efficacy in ALL xenograft mouse model showed 80-90 % reduction of leukemic cells with mutants compared to 40 % with WT. Consequently, survival was 90 % in each mutant group compared to 10 % with WT. KHYW-17 showed over 2-fold lower binding to pre-existing anti-asparaginase antibodies from ALL patients treated with l-asparaginase.

CONCLUSION

EcA variants demonstrated better pharmacological properties compared to WT that makes them good candidates for further development.

Desirable L-asparaginases for treating cancer and current research trends

Amino acid depletion therapy is a promising approach for cancer treatment. It exploits the differences in the metabolic processes between healthy and cancerous cells. Certain microbial enzymes induce cancer cell apoptosis by removing essential amino acids. L-asparaginase is an enzyme approved by the FDA for the treatment of acute lymphoblastic leukemia. The enzymes currently employed in clinics come from two different sources: Escherichia coli and Erwinia chrysanthemi. Nevertheless, the search for improved enzymes and other sources continues because of several factors, including immunogenicity, in vivo instability, and protease degradation. Before determining whether L-asparaginase is clinically useful, research should consider the Michaelis constant, turnover number, and maximal velocity. The identification of L-asparaginase from microbial sources has been the subject of various studies. The primary goals of this review are to explore the most current approaches used in the search for therapeutically useful L-asparaginases and to establish whether these investigations identified the crucial characteristics of L-asparaginases before declaring their therapeutic potential.

Expression and Biological Evaluation of an Engineered Recombinant L-asparaginase Designed by In Silico Method Based on Sequence of the Enzyme from Escherichia coli

Purpose

Medical usage of L-asparaginase (ASNase), the first-line of acute lymphoblastic leukemia treatment, is linked to allergic responses and toxicities, which necessitates the development of new bio-better ASNases. The aim of the current study was in silico design of a novel ASNase with predicted improved enzymatic properties using strategies encompassing sequence-function analysis of known ASNase mutants. Additionally, current study aimed to show that the new enzyme is active.

Methods

Based on 21 experimentally reported mutations for ASNase, a virtual library of mutated enzymes with all 7546 possible combinations of up to 4 mutations was generated. Three-dimensional models of proposed mutant enzymes were built and their in silico stabilities were calculated. The most promising mutant was selected for preparing a genetic construct suitable for expression of the designed ASNase in bacterial cells.

Results

Computational study predicted that Y176F/S241C double mutation of Escherichia coli ASNase may increase its folding stability. The designed ASNase was expressed in two different E. coli strains (Origami B(DE3) and BL21(DE3)pLysS) and then the soluble fractions prepared from the cell lysates of the host cells were used in enzyme activity assay. Results showed that enzyme activity of soluble fraction from Origami (95.4 ± 7.5 IU/0.1 mL) was four times higher than that of soluble fraction from pLysS (25.8 ± 2.5 IU/0.1 mL).

Conclusion

A novel functional double mutant ASNase with predicted improved enzymatic properties was designed and produced in E. coli. The results of the current study suggest a great commercial potential for the identified enzyme in pharmaceutical and industrial applications.

Engineering and Expression Strategies for Optimization of L-Asparaginase Development and Production

Genetic engineering for heterologous expression has advanced in recent years. Model systems such as Escherichia coli, Bacillus subtilis and Pichia pastoris are often used as host microorganisms for the enzymatic production of L-asparaginase, an enzyme widely used in the clinic for the treatment of leukemia and in bakeries for the reduction of acrylamide. Newly developed recombinant L-asparaginase (L-ASNase) may have a low affinity for asparagine, reduced catalytic activity, low stability, and increased glutaminase activity or immunogenicity. Some successful commercial preparations of L-ASNase are now available. Therefore, obtaining novel L-ASNases with improved properties suitable for food or clinical applications remains a challenge. The combination of rational design and/or directed evolution and heterologous expression has been used to create enzymes with desired characteristics. Computer design, combined with other methods, could make it possible to generate mutant libraries of novel L-ASNases without costly and time-consuming efforts. In this review, we summarize the strategies and approaches for obtaining and developing L-ASNase with improved properties.

[Approaches for improving L-asparaginase expression in heterologous systems]

L-asparaginase (EC 3.5.1.1) is one of the most demanded enzymes used in the pharmaceutical industry as a drug and in the food industry to prevent the formation of toxic acrylamide. Researchers aimed to improve specific activity and reduce side effects to create safer and more potent enzyme products. However, protein modifications and heterologous expression remain problematic in the production of asparaginases from different species. Heterologous expression in optimized producer strains is rationally organized; therefore, modified and heterologous protein expression is enhanced, which is the main strategy in the production of asparaginase. This strategy solves several problems: incorrect protein folding, metabolic load on the producer strain and codon misreading, which affects translation and final protein domains, leading to a decrease in catalytic activity. The main approaches developed to improve the heterologous expression of L-asparaginases are considered in this paper.

Asparaginase activity monitoring in pediatric acute lymphoblastic leukemia: A cross-sectional nationwide study in Spain

BACKGROUND

A cross-sectional nationwide study was designed to assess national compliance with international consensus/guidelines of monitoring asparaginase levels in children with acute lymphoblastic leukemia (ALL) treated with asparaginase in routine clinical practice.

METHODS

An ad hoc questionnaire was designed and completed by staff physicians from Hemato-Oncology Units throughout Spain.

RESULTS

A total of 39 physicians (64% pediatricians) with a mean (SD) age 43.5 (7.9) years and 15.3 (17.6) years of professional activity participated in the study. They accounted for 90% of hospitals in which children with ALL are treated in Spain. A total of 19 participants (48.7%) reported that asparaginase levels were routinely monitored (own center in 2 cases [10.5%], another hospital in 17 cases [89.5%]). Asparaginase was not monitored in 51.3% of the cases, mostly (80%) because unavailability of testing. When asparaginase was monitored, 68% of participants reported that this was done in all asparaginase-treated patients and 84% in all phases of the disease (induction, consolidation, re-induction, maintenance) with a time interval of 7 days for the pegylated form, 48 h for Erwinia asparaginase and 14 days for maintenance with the pegylated form. All participants reported that they modified treatment according to results of testing, with a limit of total depletion of ≥100 IU/L. Levels <100 or 20 IU/L were considered indicative of hypersensitivity by 46% of physicians.

CONCLUSION

There is still a gap between what is recommended and what is done in clinical practice, with more than 50% of centers not monitoring the level of asparaginase activity in pediatric ALL. Protocols for asparaginase testing in daily practice should be implemented.

Recombinant production and characterization of L-glutaminase (glsA) as a promiscuity therapeutic enzyme

Because of the therapeutical impacts of hydrolytic enzymes in different diseases, in particular malignancies, we aimed to produce a recombinant putative L-glutaminase (GLS A_SL-1) from a recently characterized halo-thermotolerant Bacillus sp. SL-1. For this purpose, the glsA gene was identified and efficiently overexpressed in the Origami™ B (DE3) strain. The yield of the purified GLS A_SL-1 was ~ 20 mg/L, indicating a significant expression of recombinant enzyme in the Origami. The enzyme activity assay revealed a significant hydrolytic effect of the recombinant GLS A_SL-1 on L-asparagine (Asn) (i.e., K_m 39.8 μM, k_cat 19.9 S^-1) with a minimal affinity for L-glutamine (Gln). The GLS A_SL-1 significantly suppressed the growth of leukemic Jurkat cells through apoptosis induction (47.5%) in the IC₅₀ dosage of the enzyme. The GLS A_SL-1 could also change the Bax/Bcl2 expression ratio, indicating its apoptotic effect on cancer cells. The in silico analysis was conducted to predict structural features related to the histidine-tag exposure in the N- or C-terminal of the recombinant GLS A_SL-1. In addition, molecular docking simulation for substrate specificity revealed a greater binding affinity of Asn to the enzyme binding-site residues than Gln, which was confirmed in experimental procedures as well. In conclusion, the current study introduced a recombinant GLS A_SL-1 with unique functional and structural features, highlighting its potential pharmaceutical and medical importance. GLS A_SL-1 represents the first annotated enzyme from Bacillus with prominent asparaginase activity, which can be considered for developing alternative enzymes in therapeutic applications. KEY POINTS: • Hydrolytic enzymes have critical applications in different types of human malignancies. • A recombinant L-glutaminase (GLS A_SL-1) was produced from halo-thermotolerant Bacillus sp. SL-1. • GLS A_SL-1 displayed a marked hydrolytic activity on L-asparagine compared to the L-glutamine. • GLS A_SL-1 with significant substrate promiscuity may be an alternative for developing novel pharmaceuticals.

Molecular cloning, characterization, and in-silico analysis of l-asparaginase from Himalayan Pseudomonas sp. PCH44

l-Asparaginase (l-ASNase) is a key enzyme used to treat acute lymphoblastic leukemia, a childhood blood cancer. Here, we report on the characterization of a recombinant l-ASNase (Ps44-asn II) from Pseudomonas sp. PCH44. The gene was identified from its genome, cloned, and overexpressed in the host Escherichia coli (E. coli). The recombinant l-ASNase (Ps44-ASNase II) was purified with a monomer size of 37.0 kDa and a homotetrameric size of 148.0 kDa. The purified Ps44-ASNase II exhibited optimum activity of 40.84 U/mg in Tris-HCl buffer (50 mM, pH 8.5) at 45 °C for 15 min. It retained 76.53% of enzyme activity at 45 °C after 120 min of incubation. The half-life and K _d values were 600 min and 1.10 × 10^-3 min^-1, respectively, at 45 °C. The kinetic constants values K _m and V _max were 0.56, 0.728 mM, and 29.41, 50.12 U/mg for l-asparagine and l-glutamine, respectively. However, k _cat for l-glutamine is more (30.91 s^-1) than l-asparagine (18.06 s^-1), suggesting that enzymes act more efficiently on l-glutamine than l-asparagine. The docking analysis of l-asparagine and l-glutamine with active site residues of the enzyme revealed a molecular basis for high l-glutaminase (L-GLNase) activity and provided insights into the role of key amino acid residues in the preferential enzymatic activities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03224-0.

Fusarium sp. L-asparaginases: purification, characterization, and potential assessment as an antileukemic chemotherapeutic agent

Asparaginases important role in the treatment of leukemia. It is part of chemotherapy in the treatment of leukemia in the last three decades. L-Asparaginase is isolated from Fusarium sp. isolated from soil and purified using ammonium sulfate precipitation and Sephadex G 100. Characterization of the crude enzyme revealed it is a metalloprotease inhibited by EDTA. Hg²⁺, Cd²⁺, and Pb²⁺ also inhibited the enzyme. Mg²⁺, Zn²⁺, and Ca²⁺ activated L-asparaginase. Furthermore, kinetic studies of purified enzyme were carried out. V_max and K_m were 0.031 M and 454 U/mL, respectively. The optimum temperature was 30 °C and the optimum pH was 7. Concerning substrate specificity, gelatin and casein in addition to L-asparagine were tested. The enzyme was found to be nonspecific that could hydrolyze all tested substrates at different rates. The maximum enzyme activity was recorded in the case of L-asparagine, followed by casein and gelatin, respectively. The molecular weight of L-asparaginase was 22.5 kDa. The antileukemic cytotoxicity assay of the enzyme against RAW2674 leukemic cell lines by MTT viability test was estimated. The enzyme exhibited antileukemic activity with IC₅₀ of 50.1 UmL^-1. The current work presents additional information regarding the purification and characterization of the enzyme produced by Fusarium sp. and its evaluation as a potential antileukemic chemotherapeutic agent.

A Novel L-Asparaginase from Hyperthermophilic Archaeon Thermococcus sibiricus: Heterologous Expression and Characterization for Biotechnology Application

L-asparaginase (L-ASNase) is a vital enzyme with a broad range of applications in medicine and food industry. Drawbacks of current commercial L-ASNases stimulate the search for better-producing sources of the enzyme, and extremophiles are especially attractive in this view. In this study, a novel L-asparaginase originating from the hyperthermophilic archaeon Thermococcus sibiricus (TsA) was expressed in Escherichia coli, purified and characterized. The enzyme is optimally active at 90 °C and pH 9.0 with a specific activity of 2164 U/mg towards L-asparagine. Kinetic parameters KM and Vmax for the enzyme are 2.8 mM and 1200 µM/min, respectively. TsA is stable in urea solutions 0-6 M and displays no significant changes of the activity in the presence of metal ions Ni2+, Cu2+, Mg2+, Zn2+ and Ca2+ and EDTA added in concentrations 1 and 10 mmol/L except for Fe3+. The enzyme retains 86% of its initial activity after 20 min incubation at 90 °C, which should be enough to reduce acrylamide formation in foods processed at elevated temperatures. TsA displays strong cytotoxic activity toward cancer cell lines K562, A549 and Sk-Br-3, while normal human fibroblasts WI-38 are almost unsensitive to it. The enzyme seems to be a promising candidate for further investigation and biotechnology application.

Microbial L-asparaginase for Application in Acrylamide Mitigation from Food: Current Research Status and Future Perspectives

L-asparaginase (E.C.3.5.1.1) hydrolyzes L-asparagine to L-aspartic acid and ammonia, which has been widely applied in the pharmaceutical and food industries. Microbes have advantages for L-asparaginase production, and there are several commercially available forms of L-asparaginase, all of which are derived from microbes. Generally, L-asparaginase has an optimum pH range of 5.0-9.0 and an optimum temperature of between 30 and 60 °C. However, the optimum temperature of L-asparaginase from hyperthermophilic archaea is considerable higher (between 85 and 100 °C). The native properties of the enzymes can be enhanced by using immobilization techniques. The stability and recyclability of immobilized enzymes makes them more suitable for food applications. This current work describes the classification, catalytic mechanism, production, purification, and immobilization of microbial L-asparaginase, focusing on its application as an effective reducer of acrylamide in fried potato products, bakery products, and coffee. This highlights the prospects of cost-effective L-asparaginase, thermostable L-asparaginase, and immobilized L-asparaginase as good candidates for food application in the future.

L-asparaginase production review: bioprocess design and biochemical characteristics

In the past decades, the production of biopharmaceuticals has gained high interest due to its great sensitivity, specificity, and lower risk of negative effects to patients. Biopharmaceuticals are mostly therapeutic recombinant proteins produced through biotechnological processes. In this context, L-asparaginase (L-asparagine amidohydrolase, L-ASNase (E.C. 3.5.1.1)) is a therapeutic enzyme that has been abundantly studied by researchers due to its antineoplastic properties. As a biopharmaceutical, L-ASNase has been used in the treatment of acute lymphoblastic leukemia (ALL), acute myeloblastic leukemia (AML), and other lymphoid malignancies, in combination with other drugs. Besides its application as a biopharmaceutical, this enzyme is widely used in food processing industries as an acrylamide mitigation agent and as a biosensor for the detection of L-asparagine in physiological fluids at nano-levels. The great demand for L-ASNase is supplied by recombinant enzymes from Escherichia coli and Erwinia chrysanthemi. However, production processes are associated to low yields and proteins associated to immunogenicity problems, which leads to the search for a better enzyme source. Considering the L-ASNase pharmacological and food importance, this review provides an overview of the current biotechnological developments in L-ASNase production and biochemical characterization aiming to improve the knowledge about its production. KEY POINTS: • Microbial enzyme applications as biopharmaceutical and in food industry • Biosynthesis process: from the microorganism to bioreactor technology • Enzyme activity and kinetic properties: crucial for the final application.

Vaccination with rEGVac elicits immunoprotection against different stages of Echinococcus granulosus life cycle: A pilot study

Vaccination against dog-sheep transmission cycle is necessary to control cystic echinococcosis (CE) infection. A multi-epitope multi-antigenic recombinant vaccine was developed-comprising the three putative vaccine antigens EG95, Eg14-3-3 and EgEnolase-was cloned and expressed. In a pilot experiment, the multi-antigen vaccine was assessed in 15 dogs and 15 sheep (five experimental groups and three animals in each group) by two subcutaneous doses 28 days apart. To evaluate the efficacy of the vaccine candidate first immunological analysis were done comprising IgG and IgE antibodies and the cytokine IL-4 in sera of the immunized dogs and sheep. Serum IgG, IgE, and IL-4, in particular in the dogs, were increased after the two rounds of vaccine candidate injection, while the total number of hydatid cysts was reduced (~85.43%). This pilot trial indicated significant immune protection efficacy against E. granulosus especially in dogs, while its efficacy in sheep was not as high as dogs. The multi-antigenic candidate vaccine is proposed as a protective vaccine modality in both dogs and sheep.

Development of Processes for Recombinant L-Asparaginase II Production by Escherichia coli Bl21 (De3): From Shaker to Bioreactors

Since 1961, L-asparaginase has been used to treat patients with acute lymphocytic leukemia. It rapidly depletes the plasma asparagine and deprives the blood cells of this circulating amino acid, essential for the metabolic cycles of cells. In the search for viable alternatives to produce L-asparaginase, this work aimed to produce this enzyme from Escherichia coli in a shaker and in a 3 L bioreactor. Three culture media were tested: defined, semi-defined and complex medium. L-asparaginase activity was quantified using the β-hydroxamate aspartic acid method. The defined medium provided the highest L-asparaginase activity. In induction studies, two inducers, lactose and its analog IPTG, were compared. Lactose was chosen as an inducer for the experiments conducted in the bioreactor due to its natural source, lower cost and lower toxicity. Batch and fed-batch cultures were carried out to reach high cell density and then start the induction. Batch cultivation provided a final cell concentration of 11 g L-1 and fed-batch cultivation produced 69.90 g L-1 of cells, which produced a volumetric activity of 43,954.79 U L-1 after lactose induction. L-asparaginase was produced in a shaker and scaled up to a bioreactor, increasing 23-fold the cell concentration and thus, the enzyme productivity.

Expression patterns and clinical significance of the potential cancer stem cell markers OCT4 and NANOG in colorectal cancer patients

Colorectal cancer (CRC) is one of the most important malignancies and causes of cancer-related deaths worldwide. Cancer stem cell markers identification could be helpful to acquire important prognostic information and develop new treatment regimens. This study aimed to evaluate the expression of OCT4 and NANOG in CRC patients and their clinical significance.

Totally 359 CRC samples were stained for OCT4 and NANOG expression using tissue microarray. The correlation between their expression and clinical and pathological features was explored.

The majority of CRC cases showed low-level expression of OCT4 (80%) and NANOG (75%). Lower expression of OCT4 was more often detected in CRC cases with no vascular involvement (P = .01). Also, a trend found between low level of OCT4 expression and absence of distant metastasis or lymph node involvement (P = .07 and P = .09, respectively). Surprisingly, a significant positive correlation was observed between NANOG expression and cellular differentiation (P = .05). Our combined analysis demonstrated that OCT4 ^low/NANOG ^low phenotype has frequently seen in colorectal cancer cases with no vascular invasion (P = .05).

Our observations indicated that higher expression of OCT4 and NANOG can confer malignant and aggressive behavior to CRC. Evaluation of the co-expression of these cancer stem cell markers can serve a new diagnostic and prognostic approach in CRC patients. These findings also suggested that simultaneous expression of OCT4 and NANOG can be considered as a therapeutic marker for targeted therapy of CRC, especially in advanced stages.

[L-asparaginases of extremophilic microorganisms in biomedicine]

L-asparaginase is extensively used in the treatment of acute lymphoblastic leukemia and several other lymphoproliferative diseases. In addition to its biomedical application, L-asparaginase is also of prospective use in food industry to reduce the formation of acrylamide, which is classified as probably neurotoxic and carcinogenic to human, and in biosensors for determination of L-asparagine level in medicine and food chemistry. The importance of L-asparaginases in different fields, disadvantages of commercial ferments, and the fact that they are widespread in nature stimuli the search for biobetter L-asparaginases from new producing microorganisms. In this regard, extremofile microorganisms exhibit unique physiological properties such as thermal stability, adaptability to extreme cold conditions, salt and pH tolerance and so provide one of the most valuable sources for novel L-asparaginases. The present review summarizes the recent results on studying the structural, functional, physicochemical and kinetic properties, stability of extremophilic L-asparaginases in comparison with their mesophilic homologues.

Expression of a recombinant bacterial L-asparaginase in human cells

Objective

l-Asparaginase (ASNase) is an enzyme used in the treatment of acute lymphoblastic leukemia (ALL). As the therapeutic ASNases has bacterial origin, severe side effects are associated with its use, among them hypersensitivity and inactivation of the enzyme. In this context, the objective of this work was to produce a recombinant ASNase of bacterial origin in human cells in order to determine the presence and consequences of potential post-translational modifications on the enzyme.

Results

Recombinant ASNase was expressed in human cells with a molecular weight of 60 kDa, larger than in Escherichia coli, which is 35 kDa. N-glycosylation analysis demonstrated that the increased molecular weight resulted from the addition of glycans to the protein by mammalian cells. The glycosylated ASNase presented in vitro activity at physiological pH and temperature. Given that glycosylation can act to reduce antigenicity by masking protein epitopes, our data may contribute to the development of an alternative ASNase in the treatment of ALL in patients who demonstrate side effects to currently marketed enzymes.

Therapeutic impacts of enzyme-responsive smart nanobiosystems

An important arena of the sophisticated nanosystems (NSs) is the combination of the responsive features of NSs with the biocatalytic properties of enzymes. The development of such smart drug delivery systems (DDSs) has seminal effectiveness in targeting, imaging, and monitoring of cancer. These NSs can exhibit site-specific delivery of the toxic cargo in response to the endogenous/exogenous stimuli. Enzyme responsive/targeted DDSs display enhanced accumulation of cargo molecules in the tumor microenvironment (TME) with a spatiotemporal controlled-release behavior. Based on the unique features of enzyme responsive/targeted DDSs, they offer incredible promise in overcoming some limitations of the currently used conventional DDSs. Taken all, targeting TME with the enzyme-responsive targeted DDSs may lead to versatile clinical outcomes in various malignancies.

Targeted enzyme delivery systems in lysosomal disorders: an innovative form of therapy for mucopolysaccharidosis

Mucopolysaccharidoses (MPSs), which are inherited lysosomal storage disorders caused by the accumulation of undegraded glycosaminoglycans, can affect the central nervous system (CNS) and elicit cognitive and behavioral issues. Currently used enzyme replacement therapy methodologies often fail to adequately treat the manifestations of the disease in the CNS and other organs such as bone, cartilage, cornea, and heart. Targeted enzyme delivery systems (EDSs) can efficiently cross biological barriers such as blood-brain barrier and provide maximal therapeutic effects with minimal side effects, and hence, offer great clinical benefits over the currently used conventional enzyme replacement therapies. In this review, we provide comprehensive insights into MPSs and explore the clinical impacts of multimodal targeted EDSs.

PEGylated gold nanoparticles-ribonuclease induced oxidative stress and apoptosis in colorectal cancer cells

Introduction: Currently, drug-induced reactive oxygen species (ROS) mediating apoptosis pathway have extensively been investigated in designing effective strategies for colorectal cancer (CRC) chemotherapy. Bovine pancreatic ribonuclease A (RNase A) represents a new class of cytotoxic and non-mutagenic enzymes, and has gained more attention as a potential anticancer modality; however, the cytosolic ribonuclease inhibitors (RIs) restrict the clinical application of this enzyme. Nowadays, nanotechnology-based diagnostic and therapeutic systems have provided potential solutions for cancer treatments.

Methods: In this study, the gold nanoparticles (AuNPs) were synthesized, stabilized by polyethylene glycol (PEG), functionalized, and covalently conjugated with RNase A. The physicochemical properties of engineered nanobiomedicine (AuNPs-PEG-RNase A) were characterized by scanning electron microscope (SEM), dynamic light scattering (DLS), and UV-vis spectrum. Then, its biological impacts including cell viability, apoptosis, and ROS production were evaluated in the SW-480 cells.

Results: The engineered nanobiomedicine, AuNPs-PEG-RNase A, was found to effectively induce apoptosis in SW-480 cells and result in a significant reduction in cancer cell viability. Besides, the maximum production of ROS was obtained after the treatment of cells with an IC50 dose of AuNPs-PEG-RNase A.

Conclusion: Based on the efficient ROS-responsiveness and the anticancer activity of RNase A of the engineered nanomedicine, this nanoscaled biologics may be considered as a potential candidate for the treatment of CRC.

Recent advances in targeted therapy of colorectal cancer: impacts of monoclonal antibodies nanoconjugates

Despite rapid advances in diagnostic and treatment approaches, the overall survival rate of cancer has not been improved. Colorectal cancer (CRC) is recognized as the third leading cause of neoplasm-related deaths worldwide, in large part due to its considerable metastasis and drug resistance. For developing new anticancer strategies, rapid progression of multimodal nanomedicines and nanoconjugates has provided promising treatment modalities for effective therapy of cancer. The limitations of cancer chemotherapy might be overcome through the use of such nanosized therapeutics, including nanoconjugates of monoclonal antibodies (mAbs) along with drugs and organic/inorganic nanoparticles. CRC cells express various molecular markers against which mAbs can be designed and used as targeting/therapeutic agents. This editorial highlights the importance of such targeted nanosystems against CRC.