Evaluation of antitumor activity of survivin short interfering RNA delivered by lipid nanoparticles in colon cancer in vitro and in vivo

Research Advances of Lipid Nanoparticles in the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a common type of gastrointestinal tract (GIT) cancer and poses an enormous threat to human health. Current strategies for metastatic colorectal cancer (mCRC) therapy primarily focus on chemotherapy, targeted therapy, immunotherapy, and radiotherapy; however, their adverse reactions and drug resistance limit their clinical application. Advances in nanotechnology have rendered lipid nanoparticles (LNPs) a promising nanomaterial-based drug delivery system for CRC therapy. LNPs can adapt to the biological characteristics of CRC by modifying their formulation, enabling the selective delivery of drugs to cancer tissues. They overcome the limitations of traditional therapies, such as poor water solubility, nonspecific biodistribution, and limited bioavailability. Herein, we review the composition and targeting strategies of LNPs for CRC therapy. Subsequently, the applications of these nanoparticles in CRC treatment including drug delivery, thermal therapy, and nucleic acid-based gene therapy are summarized with examples provided. The last section provides a glimpse into the advantages, current limitations, and prospects of LNPs in the treatment of CRC.

Advances in Pancreatic Cancer Treatment by Nano-Based Drug Delivery Systems

Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized.

Synthesis and Characterization of a New Cationic Lipid: Efficient siRNA Delivery and Anticancer Activity of Survivin-siRNA Lipoplexes for the Treatment of Lung and Breast Cancers

Survivin has been shown to be widely expressed in most tumor cells, including lung and breast cancers. Due to limited siRNA delivery, it is more challenging to target survivin using knockdown-based techniques. Designing and developing new, bifunctional chemical molecules with both selective anti-proliferative activity and effective siRNA transfection capabilities by targeting a particular gene is important to treat aggressive tumors like triple-negative breast tumors (TNBC). The cationic lipids deliver small interfering RNA (siRNA) and also display inherent anti-cancer activities; therefore, cationic lipid therapies have become very popular for treating malignant cancers. In the current study, we attempted to synthesize a series of acid-containing cationic lipids, anthranilic acid-containing mef lipids, and indoleacetic acid-containing etodo lipids etc. Further, we elucidated their bi-functional activity for their anticancer activity and survivin siRNA-mediated anti-cancer activity. Our results showed that lipoplexes with siRNA-Etodo: Dotap (ED) and siRNA-Mef: Dotap (MD) exhibited homogeneous particle size and positive zeta potential. Further, biological investigations resulted in enhanced survivin siRNA delivery with high stability, improved transfection efficiency, and anti-cancer activity. Additionally, our findings showed that survivin siRNA lipoplexes (ED and MD) in A549 cells and 4T1 cells exhibited stronger survivin knockdown, enhanced apoptosis, and G1 or G2/M phase arrest in both cell types. In vivo results revealed that treatment with survivin complexed lipoplexes significantly reduced tumor growth and tumor weight compared to control. Thus, our novel quaternary amine-based liposome formulations are predicted to open up new possibilities in the development of a simple and widely utilized platform for siRNA delivery and anti-cancer activities.

Nanoliposome-Loaded Phenolics from Nasturtium officinale Improves Health Parameters in a Colorectal Cancer Mouse Model

Nasturtium officinale contains high amounts of phytochemical compounds that work against oxidative damages leading to improved health conditions in animals as well as humans. The study was performed to investigate the health benefits of nonencapsulated and nanoliposome-encapsulated phenolic rich fractions obtained from Nasturtium officinale on mice induced colorectal cancer. The experiment focused on encapsulation efficiency in improving the effectiveness of plant bioactive compounds. Phenolic rich fractions (PRF) were successfully loaded in the nanoliposome structure, a nanometer in size, of spherical shape and with homogeneous dispersion. Induction of colorectal cancer in mice impaired weight gain and feed intake, liver function and structural characteristics of ileum, while the dietary administration of nanoliposome-encapsulated PRF regulated the expression of Caspase 3, Bax, Bcl2, iNOS and SOD genes in the tumor tissue. The addition of nonencapsulated PRF and nanoliposome encapsulated PRF at the concentration of 100 mg TPC/kg BW/day improved the genes expression, although the nanoliposome-encapsulated PRF revealed better health outcomes compared to nonencapsulated PRF. Furthermore, both PRF improved intestinal morphology when the mice were challenged with colorectal cancer. The higher health promoting activity of nanoliposome-encapsulated PRF could be associated with its enhanced intestinal absorption, bioavailability, bioaccessibility and bioactivity. Consequently, the nanoliposome-encapsulated PRF could be considered as a promising anticancer agent against colorectal cancer.

Current Advancements in Self-assembling Nanocarriers-Based siRNA Delivery for Cancer Therapy

Different therapeutic practices for treating cancers have significantly evolved to compensate and/or overcome the failures in conventional methodologies. The demonstrated potentiality in completely inhibiting the tumors and in preventing cancer relapse has made nucleic acids therapy (NAT)/gene therapy as an attractive practice. This has been made possible because NAT-based cancer treatments are highly focused on the fundamental mechanisms - i.e., silencing the expression of oncogenic genes responsible for producing abnormal proteins (via messenger RNAs (mRNAs)). However, the future clinical translation of NAT is majorly dependent upon the effective delivery of the exogenous nucleic acids (especially RNAs - e.g., short interfering RNAs (siRNAs) - herein called biological drugs). Moreover, nano-based vehicles (i.e., nanocarriers) are involved in delivering them to prevent degradation and undesired bioaccumulation while enhancing the stability of siRNAs. Herein, we have initially discussed about three major types of self-assembling nanocarriers (liposomes, polymeric nanoparticles and exosomes). Later, we have majorly reviewed recent developments in non-targeted/targeted nanocarriers for delivery of biological drugs (individual/dual) to silence the most important genes/mRNAs accountable for inducing protein abnormality. These proteins include polo-like kinase 1 (PLK1), survivin, vascular endothelial growth factor (VEGF), B-cell lymphoma/leukaemia-2 (Bcl-2) and multi-drug resistance (MDR). Besides, the consequent therapeutic effects on cancer growth, invasion and/or metastasis have also been discussed. Finally, we have comprehensively reviewed the improvements achieved in the cutting-edge cancer therapeutics while delivering siRNAs in combination with clinically approved chemotherapeutic drugs.

Advances in nanotechnology-based platforms for survivin-targeted drug discovery

INTRODUCTION

Due to its unique functional impact on multiple cancer cell circuits including proliferation, apoptosis, tumor dissemination, DNA damage repair and immune response, the inhibitor of apoptosis protein (IAP) survivin has gained high interest as a molecular target and a multitude of therapeutics were developed to interfere with survivin expression and functionality. First clinical evaluations of these therapeutics, however, were disappointing highlighting the need to develop advanced delivery systems of survivin-targeting molecules to increase stability, bioavailability as well as the selective guidance to tumor tissue.

AREAS COVERED

: This review focuses on advancements in nanocarriers to molecularly target survivin in human malignancies. A plethora of nanoparticle platforms, including liposomes, polymeric systems, dendrimers, inorganic nanocarriers, RNA/DNA nanotechnology and exosomes are discussed in the background of survivin-tailored RNA interference, small molecule inhibitors, dominant negative mutants or survivin vaccination or combined modality treatment with chemotherapeutic drugs and photo- dynamic/photothermal strategies.

EXPERT OPINION

Novel therapeutic approaches include the use of biocompatible nanoformulations carrying gene silencing or drug molecules to directly or indirectly target proteins, allow for a more precise and controlled delivery of survivin therapeutics. Moreover, surface modification of these nanocarriers may result in a tumor entity specific delivery. Therefore, nanomedicine exploiting survivin-tailored strategies in a multimodal background is considered the way forwaerd to enhance the development of future personalized medicine.

Regulation of Hedgehog Signaling by miRNAs and Nanoformulations: A Possible Therapeutic Solution for Colorectal Cancer

Hedgehog (Hh) signaling aberrations trigger differentiation and proliferation in colorectal cancer (CRC). However, the current approaches which inhibit this vital cellular pathway provoke some side effects. Therefore, it is necessary to look for new therapeutic options. MicroRNAs are small molecules that modulate expression of the target genes and can be utilized as a potential therapeutic option for CRC. On the other hand, nanoformulations have been implemented in the treatment of plethora of diseases. Owing to their excessive bioavailability, limited cytotoxicity and high specificity, nanoparticles may be considered as an alternative drug delivery platform for the Hh signaling mediated CRC. This article reviews the Hh signaling and its involvement in CRC with focus on miRNAs, nanoformulations as potential diagnostic/prognostic and therapeutics for CRC.

Lipid-Based Drug Delivery Nanoplatforms for Colorectal Cancer Therapy

Colorectal cancer (CRC) is a prevalent disease worldwide, and patients at late stages of CRC often suffer from a high mortality rate after surgery. Adjuvant chemotherapeutics (ACs) have been extensively developed to improve the survival rate of such patients, but conventionally formulated ACs inevitably distribute toxic chemotherapeutic drugs to healthy organs and thus often trigger severe side effects. CRC cells may also develop drug resistance following repeat dosing of conventional ACs, limiting their effectiveness. Given these limitations, researchers have sought to use targeted drug delivery systems (DDSs), specifically the nanotechnology-based DDSs, to deliver the ACs. As lipid-based nanoplatforms have shown the potential to improve the efficacy and safety of various cytotoxic drugs (such as paclitaxel and vincristine) in the clinical treatment of gastric cancer and leukemia, the preclinical progress of lipid-based nanoplatforms has attracted increasing interest. The lipid-based nanoplatforms might be the most promising DDSs to succeed in entering a clinical trial for CRC treatment. This review will briefly examine the history of preclinical research on lipid-based nanoplatforms, summarize the current progress, and discuss the challenges and prospects of using such approaches in the treatment of CRC.

Trace of survivin in cancer

Survivin is one of the most cancer-specific proteins overexpressed in almost all malignancies, but is nearly undetectable in most normal tissues in adults. Functionally, as a member of the inhibitor of apoptosis family, survivin has been shown to inhibit apoptosis and increase proliferation. The antiapoptotic function of survivin seems to be related to its ability to inhibit caspases directly or indirectly. Furthermore, the role of survivin in cell cycle division control is related to its role in the chromosomal passenger complex. Consistent with its determining role in these processes, survivin plays a crucial role in cancer progression and cancer cell resistance to anticancer drugs and ionizing radiation. On the basis of these findings, recently survivin has been investigated intensively as an ideal tumor biomarker. Thus, multiple molecular approaches such as use of the RNA interfering technique, antisense oligonucleotides, ribozyme, and small molecule inhibitors have been used to downregulate survivin regulation and inhibit its biological function consequently. In this review, all these approaches are explained and other compounds that induced apoptosis in different cell lines through survivin inhibition are also reported.

Toward early cancer detection: Focus on biosensing systems and biosensors for an anti-apoptotic protein survivin and survivin mRNA

The development of biosensors for cancer biomarkers has recently been expanding rapidly, offering promising biomedical applications of these sensors as highly sensitive, selective, and inexpensive bioanalytical tools that can provide alternative methodology to that afforded by the advanced hyphenated-instrumental techniques. In this review, we focus particularly on the detection of a member of the inhibitor of apoptosis proteins (IAP) family, protein survivin (Sur), a ubiquitous re-organizer of the cell life cycle with the ability to inhibit the apoptosis and induce an enhanced proliferation leading to the unimpeded cancer growth and metastasis. Herein, we critically evaluate the progress in the development of novel biosensing systems and biosensors for the detection of two survivin (Sur) biomarkers: the Sur protein and its messenger RNA (Sur mRNA), including immunosensors, electrochemical piezo- and impedance-sensors, electrochemi-luminescence biosensors, genosensors based on oligonucleotide molecular beacons (MBs) with fluorescent or electrochemical transduction, as well as the microfluidic and related analytical platforms based on solution chemistry. The in-situ applications of survivin biomarkers' detection technologies to equip nanocarriers of the controlled drug delivery systems with MB-based fluorescence imaging capability, apoptosis control, and mitigation of the acquired drug resistance are also presented and critically evaluated. Finally, we turn the attention to the application of biosensors for the analysis of Sur biomarkers in exosomes and circulating tumor cells for a non-invasive liquid biopsy. The prospect of a widespread screening for early cancers, based on inexpensive point-of-care testing using biosensors and multiplex biosensor arrays, as a means of reducing the high cancer fatality rate, is discussed.

Nanostructured lipid carriers for MicroRNA delivery in tumor gene therapy

MicroRNAs (miRNAs), which are endogenous about 20–23 nucleotides non-coding RNAs, have been acted as post-transcriptional regulators of gene expression. Current studies demonstrated that miRNAs are promising candidates for tumor gene therapy because of their important biological functions in tumor cell proliferation, metastasis, apoptosis, and drug resistance. As an important delivery system, nanostructured lipid carriers (NLCs) have great potential in tumor gene therapy, particularly for miRNA delivery, due to low toxicity, low immunogenicity, long metabolic cycles, and easy modification. This article reviews recent research progress on NLCs for miRNA delivery in tumor gene therapy and prospective applications.

Hairpin-Hairpin Molecular Beacon Interactions for Detection of Survivin mRNA in Malignant SW480 Cells

Cancer biomarkers offer unique prospects for the development of cancer diagnostics and therapy. One of such biomarkers, protein survivin (Sur), exhibits strong antiapoptotic and proliferation-enhancing properties and is heavily expressed in multiple cancers. Thus, it can be utilized to provide new modalities for modulating the cell-growth rate, essential for effective cancer treatment. Herein, we have focused on the development of a new survivin-based cancer detection platform for colorectal cancer cells SW480 using a turn-on fluorescence oligonucleotide molecular beacon (MB) probe, encoded to recognize Sur messenger RNA (mRNA). Contrary to the expectations, we have found that both the complementary target oligonucleotide strands as well as the single- and double-mismatch targets, instead of exhibiting the anticipated simple random conformations, preferentially formed secondary structure motifs by folding into small-loop hairpin structures. Such a conformation may interfere with, or even undermine, the biorecognition process. To gain better understanding of the interactions involved, we have replaced the classical Tyagi-Kramer model of interactions between a straight target oligonucleotide strand and a hairpin MB with a new model to account for the hairpin-hairpin interactions as the biorecognition principle. A detailed mechanism of these interactions has been proposed. Furthermore, in experimental work, we have demonstrated an efficient transfection of malignant SW480 cells with SurMB probes containing a fluorophore Joe (SurMB-Joe) using liposomal nanocarriers. The green emission from SurMB-Joe in transfected cancer cells, due to the hybridization of the SurMB-Joe loop with Sur mRNA hairpin target, corroborates Sur overexpression. On the other hand, healthy human-colon epithelial cells CCD 841 CoN show only negligible expression of survivin mRNA. These experiments provide the proof-of-concept for distinguishing between the cancer and normal cells by the proposed hairpin-hairpin interaction method. The single nucleotide polymorphism sensitivity and a low detection limit of 26 nM (S/N = 3σ) for complementary targets have been achieved.

Identification of survivin as a promising target for the immunotherapy of adult B-cell acute lymphoblastic leukemia

B-cell acute lymphoblastic leukemia (B-ALL) is a rare heterogeneous disease characterized by a block in lymphoid differentiation and a rapid clonal expansion of immature, non-functioning B cells. Adult B-ALL patients have a poor prognosis with less than 50% chance of survival after five years and a high relapse rate after allogeneic haematopoietic stem cell transplantation. Novel treatment approaches are required to improve the outcome for patients and the identification of B-ALL specific antigens are essential for the development of targeted immunotherapeutic treatments.

We examined twelve potential target antigens for the immunotherapy of adult B-ALL. RT-PCR indicated that only survivin and WT1 were expressed in B-ALL patient samples (7/11 and 6/11, respectively) but not normal donor control samples (0/8). Real-time quantitative (RQ)-PCR showed that survivin was the only antigen whose transcript exhibited significantly higher expression in the B-ALL samples (n = 10) compared with healthy controls (n = 4)(p = 0.015). Immunolabelling detected SSX2, SSX2IP, survivin and WT1 protein expression in all ten B-ALL samples examined, but survivin was not detectable in healthy volunteer samples. To determine whether these findings were supported by the analyses of a larger cohort of patient samples, we performed metadata analysis on an already published microarray dataset. We found that only survivin was significantly over-expressed in B-ALL patients (n = 215) compared to healthy B-cell controls (n = 12)(p = 0.013).

We have shown that survivin is frequently transcribed and translated in adult B-ALL, but not healthy donor samples, suggesting this may be a promising target patient group for survivin-mediated immunotherapy.