Simultaneous nanocarrier-mediated delivery of siRNAs and chemotherapeutic agents in cancer therapy and diagnosis: Recent advances

Recently, investigations have revealed that RNA interference (RNAi) has a remarkable potential to decrease cancer burden by downregulating genes. Among various RNAi molecules, small interfering RNA (siRNA) has been more attractive for this goal and is able to silence a target pathological path and promote the degradation of a certain mRNA, resulting in either gain or loss of function of proteins. Moreover, therapeutic siRNAs have exhibited low side effects compared to other therapeutic molecular candidates. Nevertheless, siRNA delivery has its own limitations including quick degradation in circulation, ineffective internalization and low passive uptake by cells, possible toxicity against off-target sites, and inducing unfavorable immune responses. Therefore, delivery tools must be able to specifically direct siRNAs to their target locations without inflicting detrimental effects on other sites. To conquer the mentioned problems, nanocarrier-mediated delivery of siRNAs, using inorganic nanoparticles (NPs), polymers, and lipids, has been developed as a biocompatible delivery approach. In this review, we have discussed recent advances in the siRNA delivery methods that employ nanoparticles, lipids, and polymers, as well as the inorganic-based co-delivery systems used to deliver siRNAs and anticancer agents to target cells.

LncRNA DLGAP1-AS2 overexpression associates with gastric tumorigenesis: a promising diagnostic and therapeutic target

BACKGROUND

Aberrant expression of long noncoding RNAs (lncRNAs) is associated with the progression of human cancers, including gastric cancer (GC). The function of lncRNA DLGAP1-AS2, as a promising oncogene, has been identified in several human cancers. Therefore, this study was aimed to explore the association of DLGAP1-AS2 with gastric tumorigenesis, as well.

METHODS AND RESULTS

The expression level of DLGAP1-AS2 was initially pre-evaluated in GC datasets from Gene Expression Omnibus (GEO). Moreover, qRT-PCR experiment was performed on 25 GC and 25 adjacent normal tissue samples. The Cancer Genome Atlas (TCGA) data were also analyzed for further validation. Consistent with data obtained from GEO datasets, qRT-PCR results revealed that DLGAP1-AS2 was significantly (p < 0.0032) upregulated in GC specimens compared to normal samples, which was additionally confirmed using TCGA analysis (p < 0.0001). DLGAP1-AS2 expression level was also correlated with age (p = 0.0008), lymphatic and vascular invasion (p = 0.0415) in internal samples as well as poor survival of GC patients (p = 0.00074) in GEO datasets. Also, Gene Ontology analysis illustrated that DLGAP1-AS2 may be involved in the cellular process, including hippo signaling, regulated by YAP1, as its valid downstream target, in GC samples. Moreover, ROC curve analysis showed the high accuracy of the DLGAP1-AS2 expression pattern as a diagnostic biomarker for GC.

CONCLUSION

Our findings indicated that DLGAP1-AS2 might display oncogenic properties through gastric tumorigenesis and could be suggested as a therapeutic, diagnostic, and prognostic target.

ZNF677 downregulation by promoter hypermethylation as a driver event through gastric tumorigenesis

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide, due to poor prognosis and treatment failure; demanding new diagnostic and therapeutic targets. Therefore, in the present study, the methylation and expression status of ZNF677, as a promising tumor suppressor, were investigated in GC. Gene Expression Omnibus (GEO) datasets were used to initially evaluate ZNF677 expression and methylation in GC samples. Confirmation was performed on fifty internal samples, including gastric tumors and adjacent normal specimens, using q-MSP and q-PCR methods. Further validations were done using The Cancer Genome Atlas (TCGA) data on human cancers. The obtained results in silico and experimentally illustrated that ZNF677 is significantly hypermethylated and downregulated through gastric tumorigenesis. ZNF677 methylation levels were also correlated with perineural invasion (p = 0.0382) in internal samples. Furthermore, Spearman's correlation analysis showed that ZNF677 methylation is negatively (r = -0.4614, p < 0.0001) correlated with its mRNA expression levels. ROC curve analysis also illustrated the high diagnostic value of ZNF677 methylation for early detection of GC (AUC = 0.8592). Gene set enrichment analysis further revealed that ZNF677 participates in the regulation of cellular processes such as cell proliferation in GC. Moreover, in addition to hypermethylation in other malignancies, including breast, lung, and colorectal cancers, ZNF677 was hypermethylated in precancerous gastric tissues with intestinal metaplasia, indicating its methylation as a driver event through tumorigenesis. Taken together, our results suggest ZNF677 as a potential tumor suppressor gene, which could be considered as a diagnostic and therapeutic target for GC.

Bispecific monoclonal antibodies for targeted immunotherapy of solid tumors: Recent advances and clinical trials

Bispecific antibodie (BsAbs) combine two or more epitope-recognizing sequences into a single protein molecule. The first therapeutic applications of BsAbs were focused on cancer therapy. However, these antibodies have grown to cover a wider disease spectrum, including imaging, diagnosis, prophylaxis, and therapy of inflammatory and autoimmune diseases. BsAbs can be categorized into IgG-like formats and non-IgG-like formats. Different technologies have been used for the construction of BsAbs including "CrossMAb", "Quadroma", "knobs-into-holes" and molecular cloning. The mechanism of action for BsAbs includes the induction of CDC, ADCC, ADCP, apoptosis, and recruitment of cell surface receptors, as well as activation or inhibition of signaling pathways. The first clinical trials included mainly leukemia and lymphoma, but solid tumors are now being investigated. The BsAbs bind to a tumor-specific antigen using one epitope, while the second epitope binds to immune cell receptors such as CD3, CD16, CD64, and CD89, with the goal of stimulating the immune response against cancer cells. Currently, over 20 different commercial methods have been developed for the construction of BsAbs. Three BsAbs are currently clinically approved and marketed, and more than 85 clinical trials are in progress. In the present review, we discuss recent trends in the design, engineering, clinical applications, and clinical trials of BsAbs in solid tumors.