Late-stage melanoma can metastasize to organs beyond the skin, such as lungs, liver, brain, and bone, resulting in reduced patient survival time. The incidence of melanoma is currently growing worldwide, and novel therapeutic options are needed to prevent its dissemination and to improve therapeutic results. This paper describes the use of small interfering RNA (siRNA) to silence expression of TGFβ1 and VEGFR2 as an alternative approach for melanoma treatment. These two therapeutic targets have been well-documented in tumor immune modulation and tumor angiogenesis within the tumor microenvironment (TME). Two potent siRNA candidates targeting TGFβ1 or VEGFR2 were identified with 100% identity to sequences of mouse, non-human primate (NHP), and humans. The combination of the two siRNAs was formulated with a clinically validated polypeptide nanoparticle (PNP) carrier. This PNP-packaged siRNA formulation, STP355, administered intravenously in mice bearing syngeneic melanoma tumors, demonstrated silencing of both targets and a reduction in tumor growth. STP355 also reduced tumor weight significantly, without the toxicity observed with cisplatin, resulting in prolonged survival of mice compared with this small molecule. It increased immune cell penetration into TME and reduced metastases to the lung. STP355 was more efficacious than, and somewhat additive with, immune checkpoint inhibitory monoclonal antibodies.

BackgroundRising demand for non-invasive body contouring is driven by aesthetics and the obesity epidemic. Deoxycholic acid (DCA) is the only FDA-approved injectable for fat reduction but can cause side effects and significant local skin reactions (LSR). RNA interference, using small interfering RNA (siRNA) molecules, offers targeted fat reduction by silencing genes involved in fat maintenance. STP705, a siRNA injectable targeting TGF-beta 1 and COX-2, has shown promising preclinical results both in vitro and in animal models.AimsTo evaluate the safety and tolerability of STP705 for localized fat reduction in subjects undergoing abdominoplasty.MethodsThis phase I dose-ranging, randomized, vehicle-controlled trial involved eight females undergoing abdominoplasty who received subcutaneous STP705 injections at varying concentrations and volumes in designated abdominal zones. Safety assessments, including physical exams, lab tests, ECGs, and local skin reactions (LSRs), were conducted at baseline and follow-ups. Histopathologic evaluations of biopsies collected during abdominoplasty assessed adipocyte apoptosis and tissue remodeling.ResultsSTP705 demonstrated a favorable safety profile with no clinically significant changes in lab values, vital signs, or ECGs. Adverse events (AEs) were rare and transient. The incidence, intensity, and duration of LSRs were low throughout the study. Histological analysis revealed adipocyte destruction, fat remodeling, and necrosis.ConclusionSTP705 was safe and very well-tolerated and showed preliminary efficacy in inducing adipocyte apoptosis and tissue remodeling, suggesting a safer alternative or adjunct to existing fat reduction therapies. These findings support further trials to establish the safety and efficacy of STP705 for targeted fat reduction and body contouring.Trial Registration identifier: NCT05422378

Background: Obesity and localized fat accumulation continue to drive the demand for minimally invasive body contouring technologies including injectable compounds for local fat reduction. siRNA offers a potential for an injectable to specifically target and silence genes involved in adipogenesis with minimal inflammatory side effects. Aims: This study evaluates the efficacy of STP705, an injectable containing siRNA encapsulated within histidine-lysine polypeptide (HKP) nanoparticles targeting transforming growth factor beta 1 (TGF-beta 1) and cyclooxygenase-2 (COX-2), crucial mediators in adipocyte differentiation and fat retention, using in vitro, porcine, and murine models. Methods: In vitro experiments on mouse preadipocytes and in vivo trials using Diet Induced Obese (DIO) mice and Yucatan minipigs were conducted to assess the gene silencing efficiency, tissue localization, pharmacodynamics, and safety profile of STP705. ResultsSTP705 effectively reduced the expression of TGF-beta 1 and COX-2, with a notable decrease in adipocyte volume and lipid content without adverse systemic effects. In DIO mice, the HKP-siRNA complex demonstrated precise localization to injected adipose tissue, maintaining significant gene silencing, and detectable levels of siRNA for up to 14 days post-administration. Similar results in minipigs showed a significant reduction in subcutaneous adipose tissue thickness. Conclusion: The results of these studies support the use of targeted siRNA therapy specifically targeting TGF-beta 1 and COX-2, for localized fat reduction, offering a potential minimally invasive alternative to current fat reduction methods.

Upregulation of TGFβ and Cox2 in the tumor microenvironment results in blockade of T-cell penetration into the tumor. Without access to tumor antigens, the T-cell response will not benefit from administration of the immune checkpoint antibodies. We created an intravenous polypeptide nanoparticle that can deliver two siRNAs (silencing TGFβ and Cox2). Systemic administration in mice, bearing a syngeneic orthotopic hepatocellular carcinoma (HCC), delivers the siRNAs to various cells in the liver, and significantly reduces the tumor. At 2 mg/kg (BIW) the nanoparticle demonstrated a single agent action and induced tumor growth inhibition to undetectable levels after five doses. Reducing the siRNAs to 1mg/kg BIW demonstrated greater inhibition in the presence of PD-L1 mAbs. After only three doses BIW, we could still recover a smaller tumor and, in tumor sections, showed an increase in penetration of CD4+ and CD8+ T-cells deeper into the remaining tumor that was not evident in animals treated with non-silencing siRNA. The combination of TGFβ and Cox2 siRNA co-administered in a polypeptide nanoparticle can act as a novel therapeutic alone against HCC and may augment the activity of the immune checkpoint antibodies. Silencing TGFβ and Cox2 converts an immune excluded (cold) tumor into a T-cell inflamed (hot) tumor.

The integration of fluorine atoms into biologically active organic compounds has proved to be a vital technique in small molecule drugs. This technique can substantially enhance crucial properties, including metabolic stability, lipophilicity, and bioavailability, often with a mere addition of a single fluorine atom or a trifluoromethyl group. Over the past few decades, this concept has also been applied in nucleic acid chemistry. A commonly employed 2 '-OH substitution is the introduction of a 2 '-deoxy-2 '-fluoro (2 '-F) group. The strong electronegativity of fluorine prompts the modified siRNA to readily adopt a C3 '-endo conformation, resulting in significant advantages in terms of binding affinity. To enrich the toolbox of chemical modification of oligonucleotides, the replacement of the 2 '-OH with the 2 '-O-trifluoromethyl group has been developed in RNA analog synthesis. Oligodeoxynucleotides containing the 2 '-O-trifluoromethyl group can greatly increase the thermal stability of DNA/RNA duplexes depending on the position and amount of the modification. Moreover, 2 '-O-trifluoromethylated oligodeoxynucleotide also exhibited a slightly higher resistance to snake venom phosphodiesterase than the unmodified oligodeoxynucleotide. The 2 '-O-trifluoromethylated oligonucleotides can emerge as a label to study RNA structure and function as well, or to develop DNA/RNA-based diagnostics. Hence, it is necessary to report an effective method for the synthesis, deprotection, purification, and characterization of oligonucleotides bearing a 2 '-O-trifluoromethyl group. (c) 2024 Wiley Periodicals LLC.

Although small interfering RNA (siRNA) is a key player among gene inhibition therapeutics, there are many obstacles to the development of siRNA drugs due to inherent properties of oligonucleotides, including the unsatisfactory stability of unmodified siRNA, poor pharmacokinetic distribution, and the toxicity induced by off-target effects. To maximize treatment potency, chemical modification of siRNA has undoubtedly been the most successful strategy by far. Widely applied modifications include phosphorothioate linkages, 2'-O-methyl modifications, and 2'-fluoro modifications, among others. To extend the family of chemical modifications for oligonucleotides, 2'-O-cyanoethylated RNA analogs were developed through the replacement of the 2'-hydroxyl group with a 2'-O-cyanoethyl group (-OCH2 CH2 CN). This modification can provide several advantages over unmodified RNA, such as increased stability, improved binding affinity to complementary DNA or RNA strands, and resistance to degradation by cellular nucleases. The 2'-O-cyanoethyl-modified RNAs not only are applied in RNA silencing machinery but also act as research tools for studying RNA structure and function or for developing RNA-based diagnostics. Therefore, the efficient synthesis, deprotection, purification, and characterization of 2'-O-cyanoethylated RNAs deserves more attention. This protocol describes the chemical synthesis of 2'-O-cyanoethylated nucleotides and the solid-phase synthesis, deprotection, and purification of 2'-O-cyanoethylated RNAs. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Preparation of 6-N-dimethylformamidyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl adenosine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 2: Preparation of 4-N-acetyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl cytidine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 3: Preparation of 2-N-dimethylformamidyl-5'-O-dimethoxytrityl-2'-O-cyanoethyl guanine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 4: Preparation of 5'-O-dimethoxytrityl-2'-O-2-cyanoethyl uridine 3'-(2-cyanoethyl N,N-diisopropyl)phosphoramidite Basic Protocol 5: Solid-phase synthesis of 2'-O-cyanoethylated RNA analogs Basic Protocol 6: Deprotection and purification of synthesized 2'-O-cyanoethyl-RNAs.

Supplementary Fig. S1 from Human rhomboid family-1 gene silencing causes apoptosis or autophagy to epithelial cancer cells and inhibits xenograft tumor growth

This single-center, open label, dose escalation cohort study evaluated the safety and efficacy of various doses of intralesional injections of TGF-β1/COX-2 combined with histidine-lysine polypeptide (siRNA/HKP) nanoparticle silencing therapeutic in patients with cutaneous in situ squamous cell carcinoma. Twenty-five patients (mean age: 67, SD: 10 years; 52% men) with cutaneous in situ squamous cell carcinoma participated. TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic was injected weekly for up to 6 weeks based on the following dosing cohorts: 10 μg/treatment, 20 μg/treatment, 30 μg/treatment, 60 μg/treatment, and 120 μg/treatment. The primary endpoint was the proportion of subjects with complete histological clearance. Also evaluated were the incidence/severity of treatment emergent adverse events and serious adverse events and incidence/severity of Local Skin Response. Twenty-five subjects received the TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic; 19 (76%) achieved histological clearance. In the 30 μg/treatment group and 60 μg/treatment group, percent cleared was 80% and 100%, respectively. Five subjects had 7 adverse events. There were no severe or serious adverse events; none led to treatment discontinuation, study interruption, or were related to the investigational product. Local skin response was none to minimal in most subjects, with improvement observed in the 10 μg/treatment, 20 μg/treatment, 30 μg/treatment, and 60 μg/treatment cohorts. Intralesional TGF-β1/COX-2 siRNA/HKP nanoparticle therapeutic injections appear to be noninvasive, safe, and efficacious in treating cutaneous in situ squamous cell carcinoma. The recommended doses for future study of the investigational product are 30 μg/treatment and 60 μg/treatment. J Drugs Dermatol. 2022;21(5):472-477. doi:10.36849/JDD.6384.

The non-nucleoside analog gemcitabine has been the standard of care for treating pancreatic cancer. The drug shows good potency in pancreatic cancer cells in vitro but, due to poor bioavailability, requires administration in large doses by infusion and this systemic exposure results in significant toxicity for the patient. Genes have been identified that, when silenced by siRNA, synergize with gemcitabine treatment and offer a means of reducing the gemcitabine dosage required for efficacy. However, benefiting from the synergism between the two agents requires that the gemcitabine and siRNA penetrate the same cells. To ensure co-delivery, we incorporated gemcitabine covalently within siRNAs against targets synergistic with gemcitabine (CHK1 or RAD17). We demonstrated that specific bases within an siRNA can be replaced with gemcitabine to increase efficacy. The result is a single drug molecule that simultaneously co-delivers gemcitabine and a synergistic siRNA. The siRNA-gemcitabine constructs demonstrate a 5-30-fold improvement in potency compared with gemcitabine alone. Co-delivering a CHK1 siRNA-gemcitabine construct together with a WEE1 siRNA resulted in a 10-fold improvement in IC50 compared with gemcitabine alone. These constructs demonstrate efficacy across a wide array of pancreatic tumor cells and may represent a novel therapeutic approach for treating pancreatic cancer.

Background: TGF-β1 and COX-2 overexpression plays key role in tumorigenesis of nonmelanoma skin cancer. STP705 is a combination of TGF-β1/COX-2 siRNAs formulated in histidine-lysine copolymer nanoparticle delivery system. We studied the effect of STP705 on the growth of human squamous carcinoma (A431) xenograft tumors in nude mice and viability of human cutaneous squamous carcinoma (HSC-1) cells.

e14652 Background: Cholangiocarcinoma (CCA) is a hepatobiliary cancer and although there have been advances recently there is a need for additional treatment methods for patients. Over expressions of TGF-β1 and COX-2 have been reported to play key roles in tumorigenesis of CCA. We studied the effect of STP705 on the growth of HuCCT-1 xenograft tumors in nude mice. STP705 is a TGF-β1/COX-2 specific siRNA combination product formulated in Histidine-Lysine co-Polymer nanoparticle delivery system. Methods: HuCCT-1 xenograft tumors were implanted subcutaneously into 24 BALB/c nude female mice (n = 8/group). Group 1 received vehicle control, group 2 (low-dose) received 8µg of STP705, and group 3 (high-dose) received 16µg of STP705. Intratumoral test article administration and tumor volume measurements were conducted twice a week for 3-weeks. Qualitative analysis was performed on H&E, Picrosirius red (PSR) and immunohistochemistry (IHC) stained sections of tumor tissues. Results: High- and low- dose groups of STP705 reported significantly lower mean tumor volume at day 21 (p = 0.005 & p = 0.036, respectively) as compared to control group. High-dose group reported significantly lower tumor volume at days 11 (p = 0.042), 15 (p = 0.003), and 18 (p = 0.007) as compared to the control group. IHC assessment demonstrated that STP705-treated animals had significantly lower (H-score ± SEM) TGF-β1, COX-2, HSP70, Bcl-xL and MMP-9 staining (52±9, 39±4, 178±8, 25±7 & 7±1, respectively) as compared to control animals (94±11, 66±8, 213±7, 59±8 & 11±2, respectively – with p < 0.05). Assessment of Caspase-3 and H&E (necrosis and inflammation) slides reported higher mean score for STP705-treated animals, while PSR staining reported lower fibroplasia for STP705-treated animals as compared to the control animals. Conclusions: The data suggests that STP705-treatment suppresses TGF-β1 and COX-2 expression resulting in inhibition of (i) tumor cell survival, (ii) fibrosis, (iii) promotes apoptosis, and (iv)decreased invasiveness of tumor cells. Overall, STP705 is an innovative siRNA-based treatment that results in significant suppression of tumor growth in a HuCCT-1 xenograft mouse tumor model.

Excessive skin scars due to elective operations or trauma represent a challenging clinical problem. Pathophysiology of hypertrophic scars entails a prolonged inflammatory and proliferative phase of wound healing. Over expression of TGF-β1 and COX-2 play key regulatory roles of the aberrant fibrogenic responses and proinflammatory mediators. When we silenced TGF-β1 and COX-2 expression simultaneously in primary human fibroblasts, a marked increase in the apoptotic cell population occurred in contrast to those only treated with either TGF-β1 or COX-2 siRNA alone. Furthermore, using human hypertrophic scar and skin graft implant models in mice, we observed significant size reductions of the implanted tissues following intra-scar administration of TGF-β1/COX-2 specific siRNA combination packaged with Histidine Lysine Polymer (HKP). Gene expression analyses of those treated tissues revealed silencing of the target gene along with down regulations of pro-fibrotic factors such as α-SMA, hydroxyproline acid, Collagen 1 and Collagen 3. Using TUNEL assay detection, we found that the human fibroblasts in the implanted tissues treated with the TGF-β1/COX-2siRNAs combination exhibited significant apoptotic activity. Therefore we conclude that a synergistic effect of the TGF-β1/COX-2siRNAs combination contributed to the size reductions of the hypertrophic scar implants, through activation of fibroblast apoptosis and re-balancing between scar tissue deposition and degradation.

Ocular infection with herpes simplex virus 1 can result in a chronic immunoinflammatory stromal keratitis (SK) lesion that is a significant cause of human blindness. A key to controlling SK lesion severity is to identify cellular and molecular events responsible for tissue damage and to manipulate them therapeutically. Potential targets for therapy are miRNAs, but these are minimally explored especially in responses to infection. Here, we demonstrated that Mir155 expression was up-regulated after ocular herpes simplex virus 1 infection, with the increased Mir155 expression occurring mainly in macrophages and CD4(+) T cells and to a lesser extent in neutrophils. In vivo studies indicated that Mir155 knockout mice were more resistant to herpes SK with marked suppression of T helper cells type 1 and 17 responses both in the ocular lesions and the lymphoid organs. The reduced SK lesion severity was reflected by increased phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 1 and interferon-γ receptor α-chain levels in activated CD4(+) T cells in the lymph nodes. Finally, in vivo silencing of miR-155 by the provision of antagomir-155 nanoparticles to herpes simplex virus 1-infected mice led to diminished SK lesions and corneal vascularization. In conclusion, our results indicate that miR-155 contributes to the pathogenesis of SK and represents a promising target to control SK severity.

Chemically synthesized short interfering RNA (siRNA) has ushered a new era in the application of RNA interference (RNAi) against viral genes. We have paid particular attention to respiratory viruses that wreak heavy morbidity and mortality worldwide. The clinically significant ones include respiratory syncytial virus (RSV), parainfluenza virus (PIV) (two Paramyxoviruses), and influenza virus (an Orthomyxovirus). As the infection by these viruses is clinically restricted to the respiratory tissues, mainly the lungs, the logical route for the application of the siRNA was also the same, i.e., via the nasal route. Following the initial success of single intranasal siRNA against RSV, we now offer two new strategies: (1) second-generation siRNAs, used against the paramyxoviral RNA polymerase large subunit (L), (2) siRNA cocktail with a novel transfection reagent, used against influenza virus. Based on these results, we propose the following consensus for designing intranasal antiviral siRNAs: (a) modified 19-27 nt-long double-stranded siRNAs are functional in the lung, (b) excessive 2'-OMe and 2'-F modifications in either or both strands of these siRNAs reduce efficacy, (c) limited modifications in the sense strand are beneficial, although their precise efficacy may be position-dependent, (d) cocktail of multiple siRNAs can be highly effective against multiple viral strains and subtypes.

Aptamers are a class of small nucleic acid ligands that are composed of RNA or single-stranded DNA oligonucleotides and have high specificity and affinity for their targets. Similar to antibodies, aptamers interact with their targets by recognizing a specific three-dimensional structure and are thus termed "chemical antibodies." In contrast to protein antibodies, aptamers offer unique chemical and biological characteristics based on their oligonucleotide properties. Hence, they are more suitable for the development of novel clinical applications. Aptamer technology has been widely investigated in various biomedical fields for biomarker discovery, in vitro diagnosis, in vivo imaging, and targeted therapy. This review will discuss the potential applications of aptamer technology as a new tool for targeted cancer therapy with emphasis on the development of aptamers that are able to specifically target cell surface biomarkers. Additionally, we will describe several approaches for the use of aptamers in targeted therapeutics, including aptamer-drug conjugation, aptamer-nanoparticle conjugation, aptamer-mediated targeted gene therapy, aptamer-mediated immunotherapy, and aptamer-mediated biotherapy.