Omic Approach in Non-smoker Female with Lung Squamous Cell Carcinoma Pinpoints to Germline Susceptibility and Personalized Medicine

The prognostic value of bone marrow retention index and bone marrow-to-liver ratio of baseline 18F-FDG PET/CT in diffuse large B-cell lymphoma

OBJECTIVE

To determine prognostic value of bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) measured on baseline dual-phase 18F-FDG PET/CT in a series of newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) treated homogeneously with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

PATIENTS AND METHODS

This prospective study enrolled 135 patients with newly diagnosed DLBCL. All patients underwent dual-phase 18F-FDG PET/CT. The following PET parameters were calculated for both tumor and bone marrow: maximum standardized uptake value (SUVmax) at both time points (SUVmax early and SUVmax delayed), SUVmax increment (SUVinc), RI, and BLR. Patients were treated with R-CHOP regimen and response at end of treatment was assessed.

RESULTS

The final analysis included 98 patients with complete remission. At a median follow-up of 22 months, 57 patients showed no relapse, 74 survived, and 24 died. The 2-year relapse-free survival (RFS) values for patients with higher and lower RI-bm were 20% and 65.1%, respectively (p < 0.001), and for patients with higher and lower BLR were 30.2% and 69.6%, respectively (p < 0.001). The 2-year overall survival (OS) values for patients with higher and lower RI-bm were 60% and 76.3%, respectively (p = 0.023), and for patients with higher and lower BLR were 57.3% and 78.6%, respectively (p = 0.035). Univariate analysis revealed that RI-bm and BLR were independent significant prognostic factors for both RFS and OS (hazard ratio [HR] = 4.02, p < 0.001, and HR = 3.23, p < 0.001, respectively) and (HR = 2.83, p = 0.030 and HR = 2.38, p = 0.041, respectively).

CONCLUSION

Baseline RI-bm and BLR were strong independent prognostic factors in DLBCL patients.

CLINICAL RELEVANCE STATEMENT

Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) could represent suitable and noninvasive positron emission tomography/computed tomography (PET/CT) parameters for predicting pretreatment risk in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL) who were treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy.

KEY POINTS

• Bone marrow retention index (RI-bm) and bone marrow-to-liver ratio (BLR) are powerful prognostic variables in diffuse large B-cell lymphoma (DLBCL) patients. • High BLR and RI-bm are significantly associated with poor overall survival (OS) and relapse-free survival (RFS). • RI-bm and BLR represent suitable and noninvasive risk indicators in DLBCL patients.

Loss of ACOX1 in clear cell renal cell carcinoma and its correlation with clinical features

Clear cell renal cell carcinoma (ccRCC) is a major pathological type of kidney cancer with a poor prognosis due to a lack of biomarkers for early diagnosis and prognosis prediction of ccRCC. In this study, we investigated the aberrant expression of Acyl-coenzyme A oxidase 1 (ACOX1) in ccRCC and evaluated its potential in diagnosis and prognosis. ACOX1 is the first rate-limiting enzyme in the peroxidation β-oxidation pathway and is involved in the regulation of fatty acid oxidative catabolism. The mRNA and protein levels of ACOX1 were significantly downregulated in ccRCC, and its downregulation was closely associated with the tumor-node-metastasis stage of patients. The ROC curves showed that ACOX1 possesses a high diagnostic value for ccRCC. The OS analysis suggested that lower expression of ACOX1 was closely related to the worse outcome of patients. In addition, gene set enrichment analysis suggested that expression of ACOX1 was positively correlated with CDH1, CDH2, CDKL2, and EPCAM, while negatively correlated with MMP9 and VIM, which strongly indicated that ACOX1 may inhibit the invasion and migration of ccRCC by reversing epithelial-mesenchymal transition. Furthermore, we screened out that miR-16-5p is upregulated at the mRNA transcript level in ccRCC and negatively correlated with ACOX1. In conclusion, our results showed that ACOX1 is abnormally low expressed in ccRCC, suggesting that it could serve as a diagnostic and prognostic biomarker for ccRCC. Overexpression of miR-16-5p may be responsible for the inactivation of ACOX1.

lncRNA ELFN1-AS1 enhances the progression of colon cancer by targeting miR-4270 to upregulate AURKB

The oncogenic role of lncRNA ELFN1-AS1 has been described in different cancers, including colon cancer (CC). However, how ELFN1-AS1 regulates CC malignancy remains unclear. In this study, ELFN1-AS1, AURKB, and miR-4270 expression levels in CC cells and tissues were determined using RT-qPCR and western blotting. CCK-8 and wound healing assays were also performed to analyze alterations in CC cell proliferation and migration. The expression of apoptosis-related proteins (Bax and Bcl-2) was determined via western blot analysis. RNA immunoprecipitation (RIP) assays coupled with luciferase reporter assays were employed to verify the relationship between miR-4270, ELFN1-AS1, and AURKB. An in vivo assay was performed using xenograft tumors in mice to detect the change of tumor growth. It was found that AURKB and ELFN1-AS1 expression was upregulated, whereas miR-4270 was downregulated in CC cells and tissues. ELFN1-AS1 silencing exhibited anti-proliferative, anti-migratory, and pro-apoptotic effects in CC cells. The tumor-suppressive effect of ELFN1-AS1 silencing was verified using in vivo assays. MiR-4270 was predicted to be a target of ELFN1-AS1 and AURKB as a target of miR-4270. Their interactions were further elucidated using luciferase reporter and RNA RIP assays. More importantly, treatment with a miR-4270 inhibitor not only rescued the tumor-suppressing effect of ELFN1-AS1 silencing but also abrogated the tumor suppressor functions of AURKB silencing in CC cells. Taken together, the ELFN1-AS1/miR-4270/AURKB axis facilitates CC tumorigenesis; therefore, targeting this axis might be a promising intervention in preventing CC progression.

Diagnostic performance of urine and blood microRNAs for bladder cancer: a meta-analysis

OBJECTIVE

To compare and assess the diagnostic value of urine and blood microRNAs(miRNAs) in discriminating bladder cancer (BCa).

METHODS

A total of 45 articles were selected, which included 4050 BCa cases and 3490 controls. Summary receiver operating characteristic (SROC) curve analyses were performed, an area under curve (AUC) was calculated and pooled accuracy was analyzed using Stata 16.0 software.

RESULTS

The AUC, sensitivity, and specificity for urinary miRNAs were 0.88, 0.82, and 0.81, respectively, those for blood miRNAs were 0.91, 0.86, and 0.82. For miR-143, the AUC was 0.88, with 0.79 sensitivity and 0.87 specificity. The results of subgroup analyses and meta-regression suggested the publication year, ethnicity, sample size, miRNAs type, and specimen type were possible sources of heterogeneity. The Deeks funnel plot indicated there was no significant publication bias.

CONCLUSION

Urine and blood-based miRNAs may potentially be promising biomarkers for noninvasive early detection of bladder tumor. The diagnostic accuracy of blood-based miRNAs would be better than those of urine-based ones, and multiple miRNA panels yielded more accurate results than single-miRNA assay. Besides, miR-143 is a promising candidate biomarker for diagnosing BCa. More prospective and standardized studies are required to confirm the future findings.

lncRNA NORAD promotes lung cancer progression by competitively binding to miR-28-3p with E2F2

Lung cancer (LC) is a prevailing primary tumor in the lung. lncRNA non-coding RNA activated by DNA damage (NORAD) is a popular target in human cancers. This experiment is designed to probe the mechanism of lncRNA in LC progression. NORAD expression in normal lung epithelial cells and LC cells was examined and then silenced to assess its effect on LC cell proliferation, invasion, and migration. Subcellular localization of NORAD was analyzed through online databases and then corroborated by fractionation of nuclear and cytoplasmic RNA assay. The target binding relations between NORAD and miR-28-3p and between miR-28-3p and E2F2 were verified. Eventually, LC cells with NORAD silencing were transfected with miR-28-3p inhibitor or pcDNA3.1-E2F2 to measure LC cell proliferation, invasion, and migration. NORAD was overexpressed in LC cells and NORAD knockout led to suppressed LC cell proliferation, invasion, and migration. Besides, NORAD targeted miR-28-3p and miR-28-3p targeted E2F2 transcription. Inhibiting miR-28-3p or overexpressing E2F2 could both annul the inhibitory role of si-NORAD in LC cell proliferation, invasion, and migration. Generally, our findings demonstrated that NORAD competitively bound to miR-28-3p with E2F2, to promote LC cell progression.

Role of lncRNA MIAT/miR-361-3p/CCAR2 in prostate cancer cells

The study was aimed to investigate the role and mechanism of long non-coding RNAs (lncRNA) myocardial infarction-associated transcript (MIAT) in prostate cancer. The relationships between lncRNA MIAT and miR-361-3p, miR-361-3p and cell cycle and apoptosis regulator 2 (CCAR2) were predicted by StarBase and TargetScan, and verified by dual-luciferase reporter assay and RNA pull-down assay. Quantitative real-time PCR assay was performed to detect the mRNA expression of lncRNA MIAT, miR-361-3p, CCAR2, Bax, and Bcl-2 in the prostate cancer tissues or cells. The protein levels of CCAR2, Bax, and Bcl-2 were detected by Western blot analysis. The cell viability and apoptosis were detected by MTT assay and Flow cytometry analysis, respectively. lncRNA MIAT was upregulated, while miR-361 was downregulated in the prostate cancer tissues and Du145 cells. lncRNA MIAT negatively regulated miR-361-3p expression in Du145 cells. Downregulating lncRNA MIAT decreased the cell viability, induced the cell apoptosis, increased Bax expression, and decreased Bcl-2 expression in Du145 cells, while the effects were reversed by downregulating miR-361-3p or CCAR2 upregulation. Moreover, CCAR2 upregulation reversed the effects of miR-361-3p upregulation on Du145 cell viability and apoptosis. In conclusion, lncRNA MIAT participated in prostate cancer by regulating cell proliferation and apoptosis via miR-361-3p/CCAR2 axis.

The Challenges of Patient Selection for Prostate Cancer Focal Therapy: A Retrospective Observational Multicentre Study

Increased diagnoses of silent prostate cancer (PCa) have led to overtreatment and consequent functional side effects. Focal therapy (FT) applies energy to a prostatic index lesion treating only the clinically significant PCa focus. We analysed the potential predictive factors of FT failure. We collected data from patients who underwent robot-assisted radical prostatectomy (RARP) in two high-volume hospitals from January 2017 to January 2020. The inclusion criteria were: one MRI-detected lesion with a Gleason Score (GS) of ≤7, ≤cT2a, PSA of ≤10 ng/mL, and GS 6 on a random biopsy with ≤2 positive foci out of 12. Potential oncological safety of FT was defined as the respect of clinicopathological inclusion criteria on histology specimens, no extracapsular extension, and no biochemical, local, or metastatic recurrence within 12 months. To predict FT failure, we performed uni- and multivariate logistic regression. Sixty-seven patients were enrolled. The MRI index lesion median size was 11 mm; target lesions were ISUP grade 1 in 27 patients and ISUP grade 2 in 40. Potential FT failure occurred in 32 patients, and only the PSA value resulted as a predictive parameter (p < 0.05). The main issue for FT is patient selection, mainly because of multifocal csPCa foci. Nevertheless, FT could represent a therapeutic alternative for highly selected low-risk PCa patients.

Welding Fume Instillation in Isolated Perfused Mouse Lungs-Effects of Zinc- and Copper-Containing Welding Fumes

Zinc- and copper-containing welding fumes can cause systemic inflammation after exposure in humans. Recent ex vivo studies have shown that the observed inflammation originates from exposed immune cells. In vitro studies identified the soluble fraction of metal particles as the main effectors. Isolated perfused mouse lungs (IPLs) were perfused and ventilated for 270 min. Lungs were instilled with saline solution (control), welding fume particle suspension (WFs) or the soluble fraction of the welding fumes (SF-WFs). Bronchoalveolar lavage fluid (BALF) and perfusate samples were analyzed for cytokine levels and lung tissue mRNA expression levels were analyzed via RT-PCR. All lungs instilled with WFs did not complete the experiments due to a fatal reduction in tidal volume. Accordingly, IL-6 and MPO levels were significantly higher in BALF of WF lungs compared to the control. IL-6 and MPO mRNA expression levels were also increased for WFs. Lungs instilled with SF-WFs only showed mild reactions in tidal volume, with BALF and mRNA expression levels not significantly differing from the control. Zinc- and copper-containing welding fume particles adversely affect IPLs when instilled, as evidenced by the fatal loss in tidal volume and increased cytokine expression and secretion. The effects are mainly caused by the particles, not by the soluble fraction.

Management of Fournier's gangrene during the Covid-19 pandemic era: make a virtue out of necessity

Background

Fournier’s gangrene (FG) is a necrotizing fasciitis caused by aerobic and anaerobic bacterial infection that involves genitalia and perineum. Males, in their 60 s, are more affected with 1.6 new cases/100.000/year. Main risk factors are diabetes, malignancy, inflammatory bowel disease. FG is a potentially lethal disease with a rapid and progressive involvement of subcutaneous and fascial plane. A multimodal approach with surgical debridement, antibiotic therapy, intensive support care, and hyperbaric oxygen therapy (HBOT) is often needed.

We present the inpatient management of an FG case during the Covid-19 pandemic period. A narrative review of the Literature searching “Fournier’s gangrene”, “necrotizing fasciitis” on PubMed and Scopus was performed.

Case presentation

A 60 years old man affected by diabetes mellitus, with ileostomy after colectomy for ulcerative colitis, was admitted to our Emergency Department with fever and acute pain, edema, dyschromia of right hemiscrotum, penis, and perineal region. Computed tomography revealed air-gas content and fluid-edematous thickening of these regions. Fournier’s Gangrene Severity Index was 9. A prompt broad-spectrum antibiotic therapy with Piperacillin/Tazobactam, Imipenem and Daptomycin, surgical debridement of genitalia and perineal region with vital tissue exposure, were performed. Bedside daily surgical wound medications with fibrine debridement, normal saline and povidone-iodine solutions irrigation, iodoform and fatty gauze application, were performed until discharge on the 40^th postoperative day. Every 3 days office-based medication with silver dressing, after normal saline and povidone-iodine irrigation and fibrinous tissue debridement, was performed until complete re-epithelialization of the scrotum on the 60^th postoperative day.

Conclusions

FG is burdened by a high mortality rate, up to 30%. In the literature, HBOT could improve wound restoration and disease-specific survival. Unfortunately, in our center, we do not have HBOT. Moreover, one of the pandemic period problems was the patient’s displacement and outpatient hospital management. For all these reasons we decided for a conservative inpatient management. Daily cleaning of the surgical wound allowed to obtain its complete restoration avoiding surgical graft and hyperbaric oxygen chamber therapy, without foregoing optimal outcomes.

Prognostic Value of Dual-Time-Point [18F]FDG PET/CT for Predicting Distant Metastasis after Treatment in Patients with Non-Small Cell Lung Cancer

This study aimed to evaluate the prognostic significance of 2-Deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake in the bone marrow (BM) and primary tumors on dual-time-point (DTP) PET/CT for predicting progression-free survival (PFS) and distant metastasis-free survival (DMFS) in patients with non-small cell lung cancer (NSCLC). We retrospectively analyzed DTP [18F]FDG PET/CT images from 211 patients with NSCLC. The maximum standardized uptake value (SUV) of primary lung cancer and mean [18F]FDG uptake of the BM (BM SUV) were measured from early and delayed PET/CT images, and the percent changes in these parameters (∆maximum SUV and ∆BM SUV) were calculated. On multivariate survival analysis, the maximum SUV and BM SUV on both early and delayed PET/CT scans were significantly associated with PFS, while the ∆maximum SUV and ∆BM SUV failed to show statistical significance. For DMFS, the ∆maximum SUV and ∆BM SUV were independent predictors along with the TNM stage. Distant progression was observed only in 1.3% of patients with low ∆maximum SUV and ∆BM SUV, whereas 28.2% of patients with high ∆maximum SUV and ∆BM SUV experienced distant progression. The ∆maximum SUV and ∆BM SUV on DTP [18F]FDG PET/CT were significant independent predictors for DMFS in patients with NSCLC.

Evaluation of the Predictive Role of Blood-Based Biomarkers in the Context of Suspicious Prostate MRI in Patients Undergoing Prostate Biopsy

The aim of this study was to assess the predictive value of pre-biopsy blood-based markers in patients undergoing a fusion biopsy for suspicious prostate magnetic resonance imaging (MRI). We identified 365 consecutive patients who underwent MRI-targeted and systematic prostate biopsy for an MRI scored Prostate Imaging–Reporting and Data System Version (PI-RADS) ≥ 3. We evaluated the neutrophil/lymphocyte ratio (NLR), derived neutrophil/lymphocyte ratio (dNLR), platelet/lymphocyte ratio (PLR), systemic immune inflammation index (SII), lymphocyte/monocyte ratio (LMR,) de Ritis ratio, modified Glasgow Prognostic Score (mGPS), and prognostic nutrition index (PNI). Uni- and multivariable logistic models were used to analyze the association of the biomarkers with biopsy findings. The clinical benefits of biomarkers implemented in clinical decision-making were assessed using decision curve analysis (DCA). In total, 69% and 58% of patients were diagnosed with any prostate cancer and Gleason Grade (GG) ≥ 2, respectively. On multivariable analysis, only high dNLR (odds ratio (OR) 2.61, 95% confidence interval (CI) 1.23–5.56, p = 0.02) and low PNI (OR 0.48, 95% CI 0.26–0.88, p = 0.02) remained independent predictors for GG ≥ 2. The logistic regression models with biomarkers reached AUCs of 0.824–0.849 for GG ≥ 2. The addition of dNLR and PNI did not enhance the net benefit of a standard clinical model. Finally, we created the nomogram that may help guide biopsy avoidance in patients with suspicious MRI. In patients with PI-RADS ≥ 3 lesions undergoing MRI-targeted and systematic biopsy, a high dNLR and low PNI were associated with unfavorable biopsy outcomes. Pre-biopsy blood-based biomarkers did not, however, significantly improve the discriminatory power and failed to add a clinical benefit beyond standard clinical factors.

Metastatic renal Ewing's sarcoma in adult woman: Case report and review of the literature

Primary renal extra-skeletal Ewing sarcoma is a rare neoplasm, often metastatic at diagnosis, and with a poor outcome. A multimodal approach is often the treatment of choice in this aggressive neoplasm. We present a case of primary renal extra-skeletal sarcoma in a 45-year-old woman who underwent tumor resection without clear margins. After no response to the first cycle of chemotherapy, we documented an early onset of local recurrence. The patient refused any other treatment and died four months after surgery.

Identification of Urinary Exosomal miRNAs for the Non-Invasive Diagnosis of Prostate Cancer

Background

Novel and non-invasive biomarkers with higher sensitivity and specificity for the diagnosis of prostate cancer (PCa) is urgently needed. In this study, we used next-generation sequencing (NGS) to characterize the genome-wide exosomal miRNA expression profiling in urine specimens and explored the diagnostic potential of urinary exosomal miRNAs for PCa.

Methods

Urinary exosomal microRNA expression profiling was performed by next-generation sequencing (NGS) and then validated by quantitative real-time PCR.

Results

Significant downregulation of urinary exosomal miR-375 was observed in PCa patients compared with healthy controls, while the expression levels of urinary exosomal miR-451a, miR-486-3p and miR-486-5p were found to be significantly up-regulated in the PCa patients. Furthermore, the expression level of urinary exosomal miR-375 showed a significant correlation with the clinical T-stage and bone metastasis of patients with PCa (P<0.05). Receiver operator characteristic curve demonstrated that the urinary exosomal miR-375, miR-451a, miR-486-3p and miR-486-5p levels can be used to differentiate PCa patients from healthy controls, with area under the curves (AUCs) of 0.788, 0.757, 0.704 and 0.796, respectively. The urinary exosomal miR-375 was found to be superior in discriminating between localized and metastatic PCa with an AUC of 0.806. Moreover, PCa patients can be distinguished from patients with benign prostatic hyperplasia by using a panel combining urinary exosomal miR-375 and miR-451a with an AUC of 0.726.

Conclusion

These findings demonstrate that the urinary exosomal miRNAs can serve as novel and non-invasive biomarkers for diagnosing and predicting the progression of PCa.

Age and Clinical Presentation for Primary Spontaneous Pneumothorax

Primary spontaneous pneumothorax (PSP) is a commonly known condition due to the accumulation of air in the pleural space in otherwise healthy people, without apparent underlying lung disease. To date, the exact pathogenesis of PSP is unclear, but it still represents a public health issue. We performed a review of the literature concerning the epidemiology of PSP, examining age of onset and presentation symptoms, in order to assess the possible correlation between these characteristics and its occurrence. Data concerning age, signs, and symptoms were collected. For description purposes, information regarding aetiological and anthropomorphic data was also gathered. In total, 265 papers were evaluated. Regarding age of onset, PSP is a disease that can occur in a broad age group with a double cluster (15-30 and 40-45 yr). Regarding symptoms, pain and dyspnoea (in its various forms) are the most described in PSP. Pain was recorded in 69.25% (range, 9-100%) of the population studied, whereas dyspnoea was present in an average of 54.55% (range, 27-77.1%). Tobacco exposure seems to play an important role in the early onset of PSP. Concerning age at presentation, this review highlights that PSP can occur over a broad age range. The literature appears to be consistent in reporting PSP occurrence mostly below 45 years of age. Asymptomatic PSP is an almost unseen entity. Finally, of pollutants, cigarette smoking should be considered as the most significant exogenous risk factor in the development of PSP.

Non-Smoking-Associated Lung Cancer: A distinct Entity in Terms of Tumor Biology, Patient Characteristics and Impact of Hereditary Cancer Predisposition

Non-small cell lung cancer (NSCLC) in non-, and especially in never-smoking patients is considered a biologically unique type of lung cancer, since risk factors and tumorigenic conditions, other than tobacco smoke, come into play. In this review article, we comprehensively searched and summarized the current literature with the aim to outline what exactly triggers lung cancer in non-smokers. Changes in the tumor microenvironment, distinct driver genes and genetic pathway alterations that are specific for non-smoking patients, as well as lifestyle-related risk factors apart from tobacco smoke are critically discussed. The data we have reviewed highlights once again the importance of personalized cancer therapy, i.e., careful molecular and genetic assessment of the tumor to provide tailored treatment options with optimum chances of good response-especially for the subgroups of never-smokers.

DKK3 knockdown confers negative effects on the malignant potency of head and neck squamous cell carcinoma cells via the PI3K/Akt and MAPK signaling pathways

Dickkopf‑related protein 3 (DKK3), which is a member of the Dickkopf WNT signaling pathway inhibitor family, is considered to be a tumor suppressor, due to its reduced expression in cancer cells and its ability to induce apoptosis when overexpressed by adenovirus. However, our previous study demonstrated alternative functions for DKK3 in head and neck squamous cell carcinoma (HNSCC). Our study reported that DKK3 expression was predominantly upregulated in HNSCC cell lines and tissue samples, and its expression was significantly correlated with poor prognosis. Furthermore, DKK3 overexpression in HNSCC cells significantly increased cancer cell proliferation, migration, invasion and in vivo tumor growth. These data have led to the hypothesis that DKK3 may exert oncogenic functions and may increase the malignant properties of HNSCC. The present study established a stable DKK3 knockdown cell line (HSC‑3 shDKK3) using lentivirus‑mediated short hairpin RNA, and assessed its effects on cancer cell behavior using MTT, migration and invasion assays. In addition, its effects on in vivo tumor growth were assessed using a xenograft model. Furthermore, the molecular mechanisms underlying the effects of DKK3 knockdown were investigated by microarray analysis, pathway analysis and western blotting. Compared with control cells, HSC‑3 shDKK3 cells exhibited significantly reduced proliferation, migration and invasion, and formed significantly smaller tumor masses when subcutaneously transplanted into nude mice. In addition, in HSC‑3 shDKK3 cells, the expression levels of phosphorylated (p)‑protein kinase B (Akt) (Ser473), p‑phosphoinositide 3‑kinase (PI3K) p85 (Tyr467), p‑PI3K p55 (Try199), p‑3‑phosphoinositide‑dependent protein kinase‑1 (PDK1) (Ser241) and total p38 mitogen‑activated protein kinase (MAPK) were reduced. Furthermore, phosphorylation of mechanistic target of rapamycin (mTOR) (Ser2448) was slightly decreased in HSC‑3 shDKK3 cells, which may be due to the increased expression of DEP domain‑containing mTOR‑interacting protein. Conversely, DKK3 overexpression in HSC‑3 shDKK3 cells rescued cellular proliferation, migration and invasion. With regards to expression levels, p‑PI3K and p‑PDK1 expression was not altered, whereas mTOR and p‑p38 MAPK expression was elevated. These data supported the hypothesis and indicated that DKK3 may contribute to the malignant phenotype of HNSCC cells via the PI3K/Akt/mTOR and MAPK signaling pathways.