Self-assembled RNA nanocarrier-mediated chemotherapy mixed with molecular concentrating on within the remedy of esophageal squamous cell carcinoma | Journal of Nanobiotechnology

Supplies

miRNA mimics together with miR-375, miR-4776-5p, miR-1973, miR-1246, miR-139 have been offered by Sangon Biotech. Paclitaxel (PTX) was bought from Aladdin Bio-Chem Expertise Co., LTD. Matrigel was ordered from BD Biosciences (San Jose, CA, USA) Annexin V/PI equipment have been purchased from Dojindo Molecular Applied sciences, Inc. D-luciferin was ordered from Sigma-Aldrich (St. Louis, MO, USA). Anti-EGFR antibody was bought from RriGene Applied sciences, Inc. Anti-Bax (Cat. No. 5023), Bcl-2 (Cat. No. 4223), Caspase-3 (Cat. No. 14220), Cyclin A2 (Cat. No. 4656), Cyclin B1 (Cat. No. 4135), Cyclin D1 (Cat. No. 55506) and E-Cadherin (Cat. No. 14472) antibodies have been bought from Cell Signaling Expertise (Boston, MA, USA).

Cell tradition

Human esophageal most cancers cell KYSE-150 was stored in our laboratory and recognized by the China Middle for Sort Tradition Assortment (CCTCC). Luciferase-expressing KYSE-150 cells (Luc-KYSE-150) have been constructed in our lab. Cells have been maintained in DMEM containing each FBS (10%) and antibiotics (100 µL/ml streptomycin and 100 µL/ml penicillin) at 37 °C in humidified air setting containing 5% CO₂.

Mice

4–6-week-old BALB/c nude mice have been bought from Hangzhou Ziyuan Experimental Animal Expertise Co., Ltd. (Hangzhou, China) and all experiments have been accredited by the Animal Care and Use Committee of The Affiliated Huaian No.1 Individuals’s Hospital of Nanjing Medical College (DW-P-2021-001-01).

Colony formation assay

To validate the operate of miRNA mimics on KYSE-150 cells, KYSE-150 cells (400/mL) have been cultured in 6-well plates and transfected with miRNA mimics (miR-375, miR-4776-5p, miR-1973, miR-1246, miR-139) by lipofectamine 3000. After 14 days culturing, cell colonies have been fastened with 4% PFA, stained with a 0.1% crystal violet dye, photographed, and counted.

Apoptosis evaluation

2 × 10⁵ KYSE-150 cells that have been respectively transfected with miRNA mimics (miR-375, miR-4776-5p, miR-1973, miR-1246, miR-139) have been cultured in a 6-well plate for 48 h at 37 °C. The apoptotic cells have been decided by Annexin V-FITC/PI staining and analyzed by stream cytometry (BD Accuri C6 Plus, Germany).

Migration and invasion assays

Migration and invasion of KYSE-150 cells have been detected utilizing transwell chambers. For migration, KYSE-150 cells (4 × 10⁴/effectively) have been cultured in 6-well plate for twenty-four h, and transfected with miRNA mimics (miR-375, miR-4776-5p, miR-1973, miR-1246, miR-139) by lipofectamine 3000. After transfection for six h, cells have been collected and resuspended with serum-free DMEM. Cells have been then seeded (2 × 10⁴) within the higher chamber of every insert and the medium with 10% FBS was positioned within the decrease chamber. After incubation for 48 h, cells on the higher layer of the membrane have been discarded, the cells on the decrease floor have been fastened with methanal and stained with 0.1% crystal violet dye. The stained cells have been then photographed and counted in three randomly chosen fields. The invasion assays have been carried out utilizing Matrigel-coated Transwell inserts with the identical process as migration assay.

EGFR expression in ESCC tissue and KYSE-150 cells

Tumor and adjoining esophageal tissues have been obtained from 140 sufferers who underwent surgical procedure for ESCC on the Division of Thoracic Surgical procedure, the Affiliated Huai’an No.1 Individuals’s Hospital of Nanjing Medical College. This examine was accredited by the ethics committee of Affiliated Huai’an No.1 Individuals’s Hospital, Nanjing Medical College (YX-P-2020-055-01).

ESCC tissue microarrays (TMA) have been ready by Servicebio (Wuhan, China). After deparaffinization and rehydration, sections have been handled for antigen retrieval for five min and blocked with 5% BSA for 1 h at room temperature. After 3 instances washing, tissue sections have been incubated with anti-EGFR antibody (1:150) for 3 h, and the EGFR expression was detected by the EnVision FLEX/HRP (Dako Denmark A/S). The depth and extent of EGFR expression was lastly decided and quantified utilizing the histochemical scoring system (H-score).

To check the EGFR expression in EYSE-150 cells, cells (2 × 10⁴/effectively) have been cultured on coverslips in 24-well plate for twenty-four h. After 3 instances washing, cells have been fastened with 4% paraformaldehyde for 20 min and blocked with 5% BSA for 30 min. After 3 instances washing, cells have been successively incubated with anti-EGFR antibody and Alexa 488 labeled goat anti-rabbit IgG. The expression of EGFR was lastly noticed by a confocal microscope (NIKON A1 +).

Synthesis of RNA oligomers and PTX-N3

RNA oligomers have been obtained from ExonanoRNA Biomedicine (Foshan, China), rG, rG, rC, rU, 2’F rC and a pair of’F rU phosphoramidites have been bought from Huaren Science and Expertise Co., Ltd. (Wuhu, China). 2’O-propargyl rC and rU have been ordered from Chemgene. RNA oligomers have been purified by desalting utilizing Glen Pak purification cartridges and gel electrophoresis (Bio-Rad). PTX-N3 prodrug was synthesized in accordance with earlier report. Briefly, paclitaxel, N,N′-dicyclohexyl-carbodiimide, 4-(dimethylamino) pyridine and 6-azido-hexanoic acid have been blended and reacted in 10 mL dichloromethane with an equal ratio of 1:2:1:2. The response was carried out at 25 °C with stirring for 16 h. The crude product was yielded by filtration and rotary evaporation, and eventually purified by silica gel chromatography.

Building of 4WJ-EGFR_apt-miR-375-PTX nanoparticles

The nanoparticles together with 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX have been constructed and offered by ExonanoRNA LLC.

For synthesis of RNA oligomer-PTX, RNA-6 alkynes oligomers (six 2-propargyl nucleotides in every oligomer) have been blended in DMSO, Copper sulfate/Tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA) and sodium ascorbate have been added and vibrated at 4 °C for 16 h. After response, the RNA oligomers-PTX was precipitated with 3 M sodium acetate and 100% ethanal. The compound was confirmed and purified by 16% (w/v) native PAGE in TBE buffer (89 mM Tris base, 200 mM boric acid and a pair of mM EDTA).

For the nanoparticles assembling, 4 RNA-6PTXs oligomers (4WJA, 4WJB or 4WJB-miR-375, 4WJC or 4WJC-miR-375, 4WJD) have been blended in TES buffer (50 mM Tris pH = 8.0, 50 mM NaCl, 1 mM EDTA) at equimolar concentrations, denatured at 90 °C for 10 min and cooled to 4 °C regularly. The nanoparticles together with 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX have been recognized by 12% (w/v) native PAGE in TBE buffer. The sequences of RNA-6PTXs, miR-375 and EGFR aptamer are (decrease circumstances point out 2′-F nucleotides, ^ point out the factors for PTX conjugation and the underlined letters point out EGFR aptamer):

4WJA: 5′^-uuA GG^u AAA G^cc Acc uGc AGG uGc uAc ^cGA uG^u AAu u^cA A -3′; 4WJB: 5’^-uuG AA^u uAc A^uc GGu AGc AcG GGc uGu G^cG AGG ^cuG AA^c AG -3′; 4WJB-miR-375: 5’^-uuG AA^u uAc A^uc GGu AGc AcG GGc uGu G^cG AGG ^cuG AA^c AG GcG AcG AGc ccc UcG cAc AAA cc-3′; 4WJC: 5′^-cuG uu^c AGc c^uc GcA cAG ccA GcA ^cGc Ac^c uGA A^uA GGu -3’; 4WJC-EGFR_apt: 5′^-cuG uu^c AGc c^uc GcA cAG ccA GcA ^cGc Ac^c uGA A^uA GGu Gcc uuA GuA AcG uGc uuu GAu Guc GAu ucG AcA GGA GGc -3’; 4WJD: 5’^- ccu Au^u cAG G^uG cGu Gcu GGG cuG cAG G^uG Gcu u^uA cc^u AA -3′; miR-375: 5′- UUU GUU CGU UCG GCU CGC GUG A -3′.

DLS measurement

To detect dimension distribution and floor zeta potential of 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX, samples have been dissolved in RNase free ddH₂O and detected by dynamic mild scattering (PSS Z3000).

Atomic drive microscopy

10 μL of nanoparticles (4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX) have been deposited on freshly cleaved mica and dried in a single day at room temperature. Then the mica floor was scanned by an atomic drive microscope (DMFASTSCAN2-SYS, Bruker).

Ultraviolet–seen (UV–Vis) spectroscopy

Ultraviolet–Seen (UV–Vis) Spectroscopy was decided by NANODROP 2000 (Thermo SCIENTIFIC) in transmission mode at a wavelength vary of 200–800 nm.

Tm evaluation by RT-PCR

RNA nanoparticles together with 4WJ, 4WJ-EGFRapt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFRapt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFRapt-miR-375-PTX have been respectively blended with SYBR Inexperienced II and added to 96-well plate. Samples have been denatured at 95 °C for five min and annealed to twenty °C at a fee of 0.11 °C /s. The SYBR Inexperienced II alerts have been then examined by LightCycler®480 RT-PCR. Tm worth was calculated by three impartial measurements.

Enzymatic stability assay

5 μM of 4WJ-EGFR_apt-miR-375-PTX was incubated with RNase (0.1 μg/μL) at 37 °C for various instances (0, 1, 3, 6, 12 and 24 h). The samples have been then examined by 2% agarose gel electrophoresis and the proportion of intact nanoparticles (depth of the band at a time level/depth of the band at 0 h) was quantified by Picture J.

pH stability evaluation

4WJ-EGFR_apt-miR-375-PTX was respectively incubated in PBS with pH4, 5.5 and seven.4 for various instances (0, 0.5, 1, 4, 8, 12, 24, 36 and 48 h). The ensuing samples have been examined by 16% native acrylamide PAGE and the proportion of intact nanoparticles was quantified by Picture J.

PTX launch profile

4WJ-EGFRapt-miR-375-PTX was incubated in PBS with 50% FBS for 0, 1, 2, 8, 12, 24, 36 and 48 h. The 16% native acrylamide PAGE electrophoresis was carried out to check and quantify the drug launch fee.

Confocal microscopy imaging

To analyze the mobile binding and uptake effectivity, KYSE-150 cells have been cultured in chamber slides (2 × 10⁴/effectively) for twenty-four h. Then, AF647-labeled RNA nanoparticles (400 nM) together with 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX have been respectively added and incubated at 37 °C for 12 and 24 h. Cells have been then washed 3 instances with PBS, fastened with 4% PFA for 10 min at room temperature adopted by staining with DAPI. The AF647 alerts in cells was examined and quantified utilizing a confocal microscope (NIKON A1 +).

To review the penetration capability of nanoparticles, 3D multicellular tumor spheroids have been ready by suspending KYSE-150 cells (1 × 10³) with DMEM/Matrigel (1:1, v/v) in 35 mm tradition dishes. After 10–14 days culturing, tradition medium was eliminated and cells have been washed with PBS for 3 instances, then the AF647-labeled 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX (800 nM) have been respectively added and incubated with tumor spheroids for 12 and 24 h. Then the spheroids have been fastened with 4% PFA, stained with DAPI and the AF647 alerts have been detected and quantified by confocal microscope.

In vitro cytotoxicity assay

KYSE-150 cells have been seeded in cell tradition E-plate at density of 5 × 10³/effectively and incubated in a single day at 37 °C. Cells have been then respectively handled with PBS, 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, PTX, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX for 48 h. The cell development curves have been robotically recorded on the xCELLigence System (Roche Utilized Sciences) in real-time.

Progress of 3D tumor spheroids was additional examined by remedy with aforementioned nanoparticles and PTX each 5 days for two instances. Then the spheroids have been imaged and the scale was calculated.

Western blot

KYSE-150 cells (4 × 10⁵) have been cultured in 6-well plates and handled with 10 nM of nanoparticles together with 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375, 4WJ-EGFR_apt-miR-375, 4WJ-PTX, 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX, 4WJ-EGFR_apt-miR-375-PTX and 240 nM of PTX for 48 h, then the cells have been lysed and subjected to SDS/PAGE.

After transferring the proteins onto polyvinylidene fluoride membrane, the membrane was blocked and incubated with antibodies in opposition to Bax (1:2000), Bcl2 (1:2000), caspase-3 (1:2000), Cyclin A2 (1:4000), Cyclin B1 (1:4000), Cyclin D1 (1:2000), and E-cadherin (1:2000) in a single day at 4 °C. After thrice washing, membrane was incubated with secondary antibody for 1 h. Lastly, the proteins have been visualized utilizing an enhanced chemiluminescence (ECL) detection reagent (Tanon).

Biodistribution of nanoparticles

To confirm whether or not EGFR_apt may improve the distribution of nanoparticles in KYSE-150-derived tumor tissues, 5 nmol of AF647 labeled 4WJ, 4WJ-EGFR_apt, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX have been intravenously injected into KYSE-150-bearing BALB/c nude mice, reside imaging was carried out at 2, 4, 6 and eight h after administration. Mice have been sacrificed, the organs together with livers, lungs, kidneys, spleens, hearts, and tumor tissues have been collected, the distribution of nanoparticles was scanned and quantified by reside imaging system (Bruker FX Professional).

Xenograft tumor mannequin

Feminine BALB/c nude mice (6 − 8 weeks) have been subcutaneously injected with KYSE-150 cells (1 × 10⁷/mouse). When tumors reached roughly 50 mm³ in quantity, the mice have been then randomly divided to totally different teams for following research.

In vivo tumor suppression analysis

KYSE-150 tumor-bearing mice have been randomly assigned to 10 teams and intravenously handled with PBS, 4WJ (5 nmol), 4WJ-EGFR_apt (5 nmol), 4WJ-miR-375 (5 nmol), 4WJ-EGFR_apt-miR-375 (5 nmol), PTX (120 nmol), 4WJ-PTX (5 nmol 4WJ with 120 nmol PTX), 4WJ-EGFR_apt-PTX, 4WJ-miR-375-PTX and 4WJ-EGFR_apt-miR-375-PTX each 7 days for five instances. Tumor dimension and mice weight have been measured each 3 days, the luciferase alerts in tumors have been detected each 7 days. Mice have been sacrificed 7 days after final administration, the peripheral blood was collected, the blood routine examination was carried out and the biomarkers for the liver (ALT, AST, and ALB), coronary heart (LDH, CK-MB, and CK), kidney (BUN, CREA), glucose and lipid degree in serum have been examined by an animal biochemical analyzer.

Livers, lungs, hearts, kidneys, spleens, and tumors have been eliminated, tumors have been photographed, HE staining was carried out to detect the pathological adjustments, IHC staining of Ki67 was carried out to research the proliferation of most cancers cells.

Ki67 staining

Paraffin-embedded, 5 μm thick tumor tissues have been dried at 60 °C for two h, deparaffinized in xylene and hydrated in lowering alcohol sequence (100%, 95%, 85%, 70%) earlier than Ki67 staining. Antigen retrieval was carried out by boiling the slides for five min. After 3-time washes with PBS, endogenous peroxidase was inactivated with 0.3% hydrogen peroxide at room temperature for 15 min. After 3-time washes, slides have been blocked with 5% BSA for 1 h after which stained with Ki67 for 3 h at room temperature.

The sections have been washed and incubated with HRP-labeled goat anti-rabbit IgG at room temperature for 30 min. After coloring with DAB, the counterstaining, dehydration, and vitrification have been successively carried out. Lastly, the slides have been mounted and the proportion of Ki67 optimistic cells was calculated.

Statistical evaluation

All information are offered as imply ± customary deviation and analyzed by GraphPad Prism software program (model 8.0). One- and two-way evaluation of variance have been used for a number of group comparisons. The unpaired t-test was used to match the variations between two teams. *p < 0.05 was thought-about to be statistically important.