1 Introduction

The rapid growth, diffusion, and metastasis of tumor cells are related to too little cell death or too much proliferation [1]. The weakening or loss of apoptotic capacity causes this disease. Apoptosis is a normal physiological phenomenon in which the body actively removes excess or defective cells under strict gene regulation and is also the main mechanism for maintaining normal metabolism [2, 3]. The body maintains normal physiological function by removing aging, damaged, or potentially toxic cells to maintain ontogeny or balance the proliferation and death of cells in the adult body under normal circumstances to maintain a dynamic balance between them. Tumor genesis correlates with the abnormal proliferation and differentiation of tumor cells and the changes in apoptosis genes [4]. The disorder of its regulatory mechanism will lead to tumorigenesis. Therefore, the strategy of inducing tumor cell apoptosis has become the focus of tumor therapy in recent years. Lately, the emphasis on using Chinese herbs in the oncology therapeutic field has been increasing [5]. Epidemiology and many animal experiments have confirmed that many natural ingredients in human food can block tumorigenesis and positively impact prevention and treatment. Resveratrol is a natural plant active ingredient and one of the effective tumor chemoprevention drugs [5, 6]. Resveratrol is a non-flavonoid polyphenolic compound isolated from the root of Rhizoma Rehmanniae for the first time in 1940 [7]. Its tumor consequences, particularly on Oral Squamous Cell Carcinoma (OSCC), have still not been clarified.

2 Materials and methods

2.1 Cell line

Human oral squamous cell carcinoma cell lines CAL-27, SCC-25, and KB were donated by the David Y. Zhang Laboratory, Mount Sinai Medical College (New York, NY, USA). HSC3, a human tongue squamous cell carcinoma cell line, was obtained from the Japanese Collection of Research Bioresources (JCRB) Cell Bank (Tokyo, Japan). Hypopharyngeal cancer cells (FaDu) were purchased from the American Type Culture Collection (Manassas, VA, USA) and maintained in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin at 37 °C in a 5% CO2 incubator.

2.2 Experimental reagent

2.2.1 Resveratrol

Resveratrol (Catalog #R5010, purity ≥ 99%) was obtained from Sigma-Aldrich (St. Louis, MO, USA). Dissolve and prepare the original solution of 100 mmol/L with DMSO, sub-pack, keep away from light at − 20 ℃, and set aside. Before the experiment, the RPMI1640 culture medium was diluted into different solutions, and the final concentration of DMSO was less than 0.5%.

2.2.2 Opti-MEM

Opti-MEM (Catalog #31985062) is obtained from American GIBCO company, Powder agarose (Catalog #445593) is obtained from French Biotest company, Fast Digest Bam HI (Catalog #FD0054) and Fast Digest Hind III (Catalog #FD0504) are obtained from Shanghai Thermo Scientific Company. Lipofectamine2000 (Catalog #11668019) is obtained from American Invitrogen company, plasmid mass (Catalog #D6900-0) preparation kit, TRI goat pure, Super M-MLV reverse transcriptase, Ribonuclease (RNase) inhibitor, and 2 × Power Taq PCR Master Mix are obtained from Beijing Bio Teke biotechnology limited company, SYBR Green (Catalog #S9430) is obtained from German Sigma company. Western and IP cell lysate, BCA protein concentration determination kit (Catalog #23227), and other Western blotting reagents were obtained from Shanghai Biyuntian Biotechnology Co., Ltd.

2.3 Methods

2.3.1 Cell culture

The CAL-27 cell line is a human tongue epithelial cell line. The cells were maintained in a DMEM medium containing 10% fetal bovine serum and 100 U/mL penicillin/streptomycin. They were routinely passaged at 37 ℃ and 5% CO2. KB cell line was derived from human oral epithelial carcinoma, and the SCC-25 cell line was derived from tongue squamous cell carcinoma. The above two kinds of cells were maintained in DMEM: Ham'sF12 = 1:1 medium containing 10% fetal bovine serum and 100U/mL penicillin/streptomycin and were routinely passaged at 37 ℃ and 5%CO2. The cells were passaged every 2–3 days, and the cells in the logarithmic growth phase were adopted in the experiment.

2.3.2 MTT assay was adopted to detect the inhibitory effect of different concentrations of resveratrol on tumor cells

The assay was performed using an MTT Kit (Catalog #TOX1, Sigma-Aldrich, St. Louis, MO, USA) following the manufacturer’s instructions. The inhibitory effect of GTE on the growth of three kinds of squamous cell carcinoma was determined by the MTT method. The cells in the logarithmic growth phase were inoculated in 96-well culture dishes with a density of 5 × 103/well and maintained at 5% CO2 for 24 h, and then were given different concentrations of GTE (0, 10, 25, 50, 100, 200, 400 μg/mL). Each group contained 3 multiple holes and were maintained for 72 h. After 72 h, 8 μL MTT with a 5 mg/mL concentration was added to each well. After 3 h of incubation, the supernatant was discarded, and 100 μL dimethyl sulfoxide (DMSO) was added to dissolve the crystals. The absorbance (OD) was immediately determined by enzyme labeling at 570 nm. The above experiments were repeated at least 3 times. Cell growth inhibition rate (%) = (control group OD value-administration group OD value)/control group OD value × 100%.

2.3.3 Analysis of cell cycle by flow cytometry (FCM)

CAL-27 cells in the logarithmic growth phase were maintained in a petri dish with a density of 5 × 105/well. After 24 h, different concentrations of GTE (0, 25, 50, 100 μg/mL) were added and co-maintained for 72 h. Rinse with PBS and centrifuge at 1000×g for 5 min, fix with cold 70% ethanol for 30 min, and remove by centrifugation. Before staining, the fixed solution was removed by PBS centrifugation at 1000×g for 5 min, 200 μL ribonuclease (RNase) was added, and 800 μL propidium iodide (PI) staining solution was mixed in a water bath 30 min at 37 ℃. The results were measured by flow cytometry and assessed by software.

2.3.4 Detection of protein expression by protein chip technique

CAL-27 cells were maintained in a petri dish with a diameter of 10 cm to 1 × 106/L, and 100 μg GTE was added after 24 h culture and then incubated for 48 h. After 48 h, the cells were harvested and centrifuged at 1000 r/min for 10 min at the temperature of 4 ℃. The supernatant was discarded, and the cells were rinsed with PBS twice to collect the lower sediment. 300 μL of cell lysate containing protease inhibitor was added to each precipitated cell, and the 3–5 min of the cell was lysed. The lysate was treated with ultrasound for 15 s 2 times, then 14,000 r/min centrifugation 15 min at the temperature of 4 ℃. The BCA protein assay kit determined the protein concentration. The cell extract containing 300 μg protein was added to a slot across the full gel width, and the protein was separated by Sodium Dodecyl Sulfate (SDS) polyacrylamide gel electrophoresis. Transfer the protein to the nitrocellulose membrane, incubated in 5% milk or 3%BSA at room temperature for 1 h, and entrap the membrane with a device with 20 swimming lanes (Bio-Rad, Hercules, CA). Two or three kinds of primary antibodies were added to each swimming lane and spent the night at the temperature of 4 ℃. After washing the membrane, the second antibody was added, and 45 min was incubated at room temperature. Using Chemi DocXRS system imaging and scanning optical density, the optical density of different corresponding protein expression levels differs. The above experiments were repeated at least 3 times.

2.3.5 Detection of protein expression by Western blot

CAL-27 cell line was selected as the representative to verify the expression of Noncoding RNA Activated by DNA Damage (NORAD), Insulin-Like Growth Factor 2 mRNA-Binding Protein 2 (IGF2BP2), and Phosphoinositide-Dependent Protein Kinase-1 (PDK1) proteins. The cells were maintained in a petri dish with a diameter of 10 cm, and the concentration was 1 × 106 × 10 ~ 6 × 10 ~ 6 ppm L. After 24 h of culture, GTE (0, 10, 25, 50, 100 μg/mL) was added and incubated for 48 h. After 48 h, the cells were harvested, and 10 min was centrifuged by 1000 r/min at the temperature of 4 ℃. Remove the supernatant, rinse the cells with PBS twice, and collect the lower precipitates. The protein was extracted using the above method, and 20 μg protein was transferred to a nitrocellulose membrane by 10%SDS polyacrylamide gel electrophoresis. The first antibody of CDK4, CDK6, and p-PDK1 was added to the nitrocellulose membrane (diluted by 1:1000) and overnight at the temperature of 4 ℃. After rinsing the membrane, the second antibody was added and incubated at room temperature for 1 h. The protein emission signal was measured by autoradiography, with β-actin (diluted by 10,000) as the internal control. The above experiments were repeated at least 3 times.

2.3.6 Liposome transfection

RNA interference technique knocks down the expression level of NORAD in cells CAL-27 cells were inoculated into 6-well plates and divided into si-NORAD- 1 group, si-NORAD-2 group, and si-NORAD-3 group according to the transfection of the si-NORAD plasmid. When the fusion degree of cells reached 30–45%, 500 μL medium without bovine serum was mixed with 5 μL Lipofectamine 2000, and 500 μL medium without bovine serum was mixed with 5 μL si RNA at room temperature after 5 min. The above two samples were mixed together and placed for 20 min at room temperature, then inoculated in a 6-well plate, maintained in an incubator for 4–6 h, and then replaced with fresh 1640 complete medium. QRT-PCR measured transfection efficiency after 24–48 h, and Western blotting measured protein expression after 48–72 h. The above experiments were repeated at least 3 times.

2.3.7 Cell scratch healing test to detect the migration ability of cancer cells

(1) Inoculation cells: the cells in the logarithmic growth phase were inoculated in a 6-well plate, about 3 × 105 cells per well and evenly distributed, maintained in 1640 complete medium, and marked with 5 parallel lines on the back of the 6-well plate. (2) artificial scratches t 3 × 105 cells per well and evenly distributed, maintained in 1640 complete medium, and marked with 5 parallel lines on the back of the 6-well plate. (3) Artificial scratches: 24 h after transfection, 200 μL gun head was adopted to draw two straight lines perpendicular to the parallel line on the back of the cell, PBS was rinsed twice, and then 1640 medium containing 1% fetal bovine serum was added to 2 mL. The healing ability of the cell was adopted to detect the migration ability of the cell. (4) The migration distance of the cells to the scratch area was carefully observed and photographed under an inverted microscope at 0 h, 24 h after that. The scratch healing area was calculated using ImageJ software. The above experiments were repeated at least 3 times.

2.3.8 Trans well invasion experiment

(1) The Trans well chamber was adopted with an 8 μ m pore diameter and 6.5 mm diameter. The upper chamber of the trans well chamber was coated with Matrigel matrix glue, dried at the temperature of 4 ℃, and rinsed gently with 1640 serum-free medium. (2) The cells were digested and counted after being maintained for 24 h. The cells in each group were made into serum-free 1640 single-cell suspension containing Bovine Serum Albumin (BSA) and transferred to the upper chamber of the Trans well chamber according to 2 × 10 5 cells. The lower chamber was 1640 medium containing 10% Fetal Bovine Serum (FBS). (3) after routine culture for 12 h, take out the chamber, discard the liquid in the upper chamber, rinse with Phosphate-Buffered Saline (PBS), gently wipe off the invasive cells in the upper chamber with cotton swabs, fix the membrane with 4% paraformaldehyde, then dye 15 min with crystal violet, rinse with PBS, and then take pictures under a high-power microscope and randomly select 10 visual fields to count and take the mean. The above experiments were repeated at least 3 times.

2.3.9 CCK-8 experimental detection of cell proliferation

The cells in each group were counted and inoculated in a 96-well plate with a density of 5 × 103 cells per well and 100 μL medium. There were 5 multiple holes in each group. 10% CCK-8 reagent (Dojindo) was added at 24, 48, 72, and 96 h, incubated at 37 ℃ for 1.5 h, and the value of 450 nma was measured by enzyme labeling instrument. The cell proliferation rate was calculated.

2.4 Statistical analysis

Methylthiazolyldiphenyl-Tetrazolium Bromide (MTT), qRT-PCR, WB, invasion, and scratch healing were repeated 3 times. The data were assessed by SPSS21.0 statistical software, and the cell growth curve was drawn by GraphPadPrism8.0 software. The exploratory values are expressed as mean, standard error, and the normally distributed measured data were especially compared to the two groups using the t-test. The distinctions were statistically important (P < 0.05 or P < 0.01). software, and the cell growth curve was drawn by GraphPadPrism8.0 software. The exploratory values are expressed as mean, standard error, and the normally distributed measured data were especially compared to the two groups using the t-test. The distinctions were statistically important (P < 0.05 or P < 0.01).

3 Results

3.1 Comparison of inhibitory effects of resveratrol on OSCC cell lines with various concentrations

The inhibitory rates of resveratrol at 50, 100, 200, 400 μg/mL on CAL-27, 100, 200, 400 μg/mL resveratrol on KB and 25, 50, 100, 200, 400 μg/mL resveratrol SCC-25 cells were increased. Among the three cell lines tested, CAL-27 demonstrated the highest sensitivity to resveratrol, as evidenced by its lowest IC50 value (70 μg/mL). This sensitivity made it a suitable model for evaluating the mechanistic effects of resveratrol. The statistical difference was discovered in the amount of the drug fashion (P < 0.05). The 50% inhibitory concentration (IC50) of resveratrol on CAL-27, KB, and SCC-25 cells was 70, 145, and 125 μg/mL, respectively. All the results are indicated in Table 1.

Table 1 Comparison of inhibitory effects of resveratrol on squamous cell carcinoma cell lines with different concentrations [x ± s, %]
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3.2 Cellular cycle of CAL-27 cells with an increased concentration gradient of resveratrol

Secondly, we found 50 μg/mL resveratrol mediated G2/M arrest of CAL-27 cells (P < 0.05). Resveratrol (100 μg/mL) could mediate the S phase and G 2/M phase arrest of CAL-27 cells (P < 0.05). The amounts of cells in the G-0/G-1 phase are downregulated. All the results are indicated in Table 2.

Table 2 Cellular cycle of CAL-27 cells with increased concentration gradient of resveratrol [x ± s, %]
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3.3 The levels of various proteins in CAL 27 cells with treatment of resveratrol

We adopted protein chip technology to analyze the effect of GTE on the signal transduction-related proteins in CAL-27 cells. In total, 107 phosphorylated and non-phosphorylated proteins were measured, and 13 proteins changed significantly (P < 0.05). The protein levels of c PKC α and Notch 4 were upregulated, while the expressions of p-ERK, p-PDK1, p-Cdc2, p-RB, NORAD, IGF2BP2, CDK2, Cdc2P34, Cyclin E, 14-3-3beta and XIAP were down-regulated. All the results are indicated in Fig. 1.

Fig. 1
figure 1

Alterations of related proteins in CAL−27 cells with 100 μg/mL resveratrol for 48 h

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3.4 Comparison of detecting protein levels

NORAD, IGF2BP2 and PDK1 levels in CAL-27 cells treated with 25, 50, 100 μg/mL resveratrol decreased. Meanwhile, the higher the concentration of resveratrol, the higher the %age of inhibition. and the variations had statistical distinctions (P < 0.05). All the results are indicated in Fig. 2 and Table 3.

Fig. 2
figure 2

Electrophoretic map of NORAD, IGF2BP2, and PDK1 protein expression in CAL-27 cells treated with different concentrations of resveratrol. A is the control group; B is 10 μg/mL; C is 25 μg/mL; D is 50 μg/mL; E is 100 μg/mL resveratrol

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Table 3 Levels of NORAD, IGF2BP2 and PDK1 in CAL-27 cells with
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3.5 NORAD effect on the proliferative cells of cancer

Compared with the CAL-27 group, the cell proliferative capability of the si-NORAD—1 and si-NORAD-2 groups was obviously weaker at 48 h, 72 h, and 96 h, but there was no difference between the si-NORAD—1 group and the si-NORAD-2 group. The results indicated that the proliferative capability of CAL-27 cells decreased largely after interfering with NORAD expression. All the results are indicated in Fig. 3.

Fig. 3
figure 3

Cell proliferative alterations in CAL-27 cells after NORAD knockdown in Con., si-NORAD- 1, and si-NORAD-2 groups

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3.6 NORAD has an influence on the capacity of cancerous cells to migrate

The results suggested that markable differences were observed in the percentage of scratch healing area between si-NORAD-1 and si-NORAD-2 groups compared with the Con group [(0.43% ± 0.06) vs (0.81 ± 0.07), (0.48 ± 0.04) vs (0.83 ± 0.08), P < 0.05]. No great differences existed between si-NORAD-1 and si-NORAD-2 groups. The migration ability of YES-2/CDDP-R cells decreased significantly after knocking down the expression of NORAD (P < 0.05). All the results are indicated in Fig. 4.

Fig. 4
figure 4

Changes in cell migration ability of CAL-27 cells after NORAD knockdown in the Con group, si-NORAD- 1 group and si-NORAD-2 group

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3.7 NORAD effect on the invasive ability of cancer cells

We assessed the effect of NORAD on the invasive ability of CAL-27 cells. After 24 h, the cells of the Con group, si-NORAD-1 group and si-NORAD-2 group could pass through the Matrigel filter membrane. The number of transmembrane cells in the Con group, si-NORAD-1 group and si-NORAD-2 group was 66.03 ± 14.01, 12.35 ± 5.03, and 18.01 ± 5.04 respectively. The amounts of trans-membrane units in si-NORAD-1 and si-NORAD-2 groups were largely greater than Con group (12.34 ± 5.01) vs (66.04 ± 14.02), (18.01 ± 5.02) vs (66.05 ± 14.02), P < 0.05. The invasive capability of CAL-27 cells decreased significantly after knocking down the expression of NORAD (P < 0.05). All the results are indicated in Fig. 5.

Fig. 5
figure 5

Changes in the invasive ability of CAL-27 cells after NORAD knockdown in the Con group, si-NORAD-1 group and si-NORAD-2 group

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3.8 IGF2BP2 effect on the proliferation of cancer cells

In the IGF2BP2 silencing group of HSC3 and CAL-27 cell lines, the expression of IGF2BP2 was greatly decreased. The proliferative ability was measured by the CCK-8 test. The proliferative rate of the IGF2BP2 knockout group decreased significantly (P < 0.05), decreasing to 69. 13% in HSC3 and 74.01% in CAL-27 (P < 0.001). All the results are indicated in Figs. 6 and 7.

Fig. 6
figure 6

mRNA and protein expression in IGF2BP2 knockdown group. The mRNA expression of the IGF2BP2 knockout group decreased in HSC3 and CAL-27, and the protein expression of the IGF2BP2 knockout group decreased significantly in HSC3 and CAL-27 (P < 0.05)

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Fig. 7
figure 7

Down-regulation of IGF2BP2 expression in HSC3 and CAL-27 cell lines inhibits proliferation. a Down-regulation of IGF2BP2 expression in HSC3 cell line inhibited proliferation, while down-regulation of IGF2BP2 expression in b CAL-27 cell line inhibited proliferation

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3.9 IGF2BP2 effect on the invasive ability of cancer cells

Compared to the negative control group, the invasive ability in IGF2BP2 knockout decreased significantly, which downregulated to 72.85% in HSC3 and 52.44% in CAL-27 (P < 0.001, Fig. 8).

Fig. 8
figure 8

Down-regulation of IGF2BP2 expression in HSC3 and CAL-27 cell lines to inhibit invasion. 20 times crystal violet staining and taking pictures under the microscope

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3.10 PDK1 effects on the proliferation of tumor cells

In order to analyze the effect of PDK1 on the proliferation of tumor cells, a CCK8 proliferation assay was adopted to detect the proliferative activity of hypopharyngeal cancer cells. It was found that the proliferative activity of hypopharyngeal cancer cells decreased after interfering with the expression of PDK1, while the proliferative activity of hypopharyngeal cancer cells was significantly enhanced after overexpression of PDK1 (P < 0.05). All the results are indicated in Fig. 9.

Fig. 9
figure 9

CCK8 test to detect the ability of cell proliferation. A The proliferative activity of tumor cells decreased after interfering with the expression of PDK1. B The proliferative activity of tumor cells was enhanced after overexpression of PDK1. * P < 0.05

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3.11 PDK1 effects on migration and invasion of tumor cells

By adding the target cells to the upper chamber and adding a medium containing serum to the lower chamber, we induced the cells to move to the lower chamber. Finally, crystal violet staining was adopted to count the cells at the bottom of the chamber to evaluate the ability of migration and invasion. The stably silenced/overexpressed PDK1 and control cells were seeded into the superior chamber. After 24 h and 36 h, the cells were fixed and stained with crystal violet, and the images were harvested under a microscope. As indicated in the figure, the number of migrating cells of oral squamous cell carcinoma in the Control group and Lv-PDK1-RNAi group was 234.62 ± 38.27and 141.35 ± 38.72 respectively, and the number of invasive cells was 119.03 ± 19.53, 72.68 ± 11.26 respectively. The number of migrating cells in the Control group and Lv-PDK1-RNAi group was 249.35 ± 46.51 and 553.82 ± 64.78 respectively, and the number of invasive cells was 131.42 ± 26.28 and 229.66 ± 44.58 respectively, indicating that PDK1 promoted the migration and invasion of tumour cells. All the results are indicated in Fig. 10.

Fig. 10
figure 10

Changes of migration and invasion ability of oral squamous cell carcinoma cells after overexpression ofPDK1. A The number of tumor cell migrations increased significantly after overexpression of PDK1. B The number of invasive cells overexpressing PDK1 was significantly increased. * P < 0.05

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4 Discussions

Resveratrol is non-flavonoid polyphenol, which is chemically called cyclopentadienol [8]. Recent studies have shown that resveratrol has antagonistic effects on a variety of tumor cells in multiple systems, such as digestion, hematopoiesis, respiration, reproduction, and so on [7, 9, 10], and has an inhibitory effect on the initiation, promotion, and development of tumor cells [11, 12]. However, there is no agreement on the specific mechanism of apoptosis induced by resveratrol in academic circles. NORAD, also called LINC00657, is a kind of lncRNA located in chromosome 20q11.23, which is 5.3 kb in length and widely exists [13]. NORAD contains 10 repetitive sequences with different structural motifs [14], which is very important for maintaining the stability of the genome. In an anoxic microenvironment, tumor cells enhance the proliferation of tumor stem cells by secreting exocrine bodies containing lncRNA, thus promoting tumor proliferation and metastasis.

Resveratrol exhibits significant therapeutic potential in oral squamous cell carcinoma (OSCC). Our findings reveal that resveratrol inhibits OSCC cell proliferation, induces S and G2/M phase arrest, and downregulates the expression of NORAD, IGF2BP2, and PDK1, key molecules involved in cancer progression. These observations are consistent with previous studies reporting the anti-proliferative and pro-apoptotic effects of resveratrol across various cancer types, including breast, lung, and colorectal cancers [5, 6].

In recent years, some researchers have put forward the theory that lncRNA is involved in a variety of pathological processes of tumors as a competitive endogenous RNA (ceRNA) [15]. According to this theory, lncRNA containing miRNA response elements plays a carcinogenic or inhibitory role by competitively binding with miRNA and modulating the performance of miRNA-specific sequences. Consistent with this theory, NORAD can be adopted as ceRNA to regulate the occurrence and development of tumors. In addition, NORAD can activate a variety of signal pathways of tumorigenesis or induce epithelial-mesenchymal transformation (EMT), thus giving full play to its metastatic characteristics in tumor cells [16]. The proliferative capability of CAL-27 cells decreased largely, later interfering with NORAD expression, and the migratory and invasive capability of YES-2/CDDP-R cells decreased significantly after knocking down NORAD expression [15,16,17].

Consistent with the previous studies, more evidence show that NORAD is in a state of disorder in different types of tumours and contributes to pathological cancerous cellular growth and metastasis. IGF2BP2 is essential for the body's growth and development [18]. Mice with IGF2BP2 knockout showed slower linear growth, higher energy metabolic rate, enhanced capacity for glucose resistance, insulin sensitivities, and tolerance to dietary-related fatness and the development of fatty liver, and even had a longer life span [19]. On the other hand, IGF2BP2 can be expressed as a tumor promoter. High expression of IGF2BP2 is discovered in coupled of cancerous tissues and is related to tumor progression and prognosis [20]. IGF2BP2, known for its tumor-promoting properties, was downregulated by resveratrol treatment. This aligns with the findings that IGF2BP2 knockdown inhibits OSCC cell proliferation and metastasis [21]. Our study extends this understanding by demonstrating that resveratrol not only reduces IGF2BP2 expression but also diminishes its downstream effects on key pathways, such as Mitogen-Activated Protein Kinase (MAPK) signaling.

PDK1 is a protein composed of 556 amino acids. PDK1 is regarded as the main regulator of the related kinase family and is indispensable in cell physiological activities. At present, studies have indicated that PDK1 is considered to be an ideal target for intervention in a variety of tumors. PDK1 is highly expressed in gastric cancer, which is a tumor marker of tumor progression and poor prognosis. In most cases [22], the high expression of PDK1 protein in multitype carcinomas is due to gene amplification. PDK1 transcription in melanoma was significantly larger than that in nevus and further increased in metastatic melanoma. PDK1 is up-regulated in a large number of patients with acute myeloid leukemia, and the therapeutic effect of this part of patients is poor. In cellular functional experiments, overexpression of PDK1 can promote the anchor-independent growth of breast cancer cells, as well as promote tumor growth in nude mice. PDK1 is deeply involved in tumorigenesis. After interfering with PDK1 transcription in breast cancer, the ability of tumor cell migration and metastasis is significantly decreased. Our results confirm that resveratrol suppresses PDK1 expression, leading to reduced cancer cell growth and invasion. These findings suggest that PDK1 may serve as a potential therapeutic target in OSCC management.

In contrast to most studies using CAL-27, it is worth noting that the less sensitive SCC-25 and KB lines showed varying responses to resveratrol. While this study focused on the most sensitive line (CAL-27) to elucidate mechanistic insights, future research should investigate the differential responses of less sensitive lines to optimize resveratrol-based therapies.

5 Conclusion

In conclusion, resveratrol can affect the expression of cell cycle-related protein molecules through many signal cascades, thus down-regulating the expansion of several types of human oral squamous cell carcinoma and malignant cells. Resveratrol has a direct anti-tumor effect, which lays a research foundation for the development of resveratrol as an anti-tumor prescription drug and its application in cancer cell management and treatment.