Worldwide, human pancreatic cancer is a rare malignancy with a poor prognosis. Long non-coding RNAs (lncRNAs) are known to have a crucial role in cancer occurrence and progression; however, the role of pseudogene-expressed lncRNAs, a major type of lncRNA, have not been thoroughly analyzed in cancer. Therefore, the present study focused on zinc finger protein 91 pseudogene (ZFP91-P). ZFP91-P expression was initially detected in two pancreatic cancer cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and the highest expression of ZFP91-P was found in the BXPC-3-H cell line. Subsequently, BXPC-3-H cells were transfected with ZFP91-P short hairpin RNA (shRNA) using a plasmid vector and termed shZFP91-P. Cells transfected with negative control plasmid vector were termed shCon. MTT and Transwell assays were performed to analyze the proliferation and migration of BXPC-3-H cells, respectively, and western blotting was used to detect epithelial-mesenchymal transition markers, including vimentin and β-catenin. The present study showed that depletion of ZFP91-P markedly decreased pancreatic cancer cell proliferation and inhibited cell migration capacity. In addition, the expression of β-catenin increased while vimentin expression decreased. The current findings suggest that high expression of ZFP91-P promotes the migration of BXPC-3-H cells and may be a novel marker for early diagnosis for pancreatic cancer.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer in the world, yet current treatment options are associated with limited success. The aim of the present study was to investigate the expression of ferritin in HNSCC and clarify whether it may serve as a biomarker for predicting HNSCC metastasis. The chemiluminescent immunoassay method was used to investigate the differences in the serum ferritin (SF) levels between patients with and without tumors, and between HNSCC with and without lymph node metastasis. The iron content and expression levels of ferritin were detected to verify the differences between tumor and normal tissues, and between HNSCC without and with lymph node metastasis. Data from the Gene Expression Omnibus (GEO) dataset was used to support the aforementioned results. No statistically significant difference in the SF level was observed between patients with and without tumors. Iron content and expression levels of ferritin heavy chain (FTH) and ferritin light chain (FTL) were higher in tumor tissues compared with normal tissues. The iron content and expression levels of SF, FTH and FTL were increased in HNSCC with metastasis compared with HNSCC without metastasis. The GEO dataset further verified the results and reported that the expression level of FTH was correlated with the prognosis of patients with HNSCC. Ferritin may not be a biomarker for the early diagnosis of HNSCC. However, an association exists between the expression level of ferritin and HNSCC cervical metastasis. SF may be a potential biomarker for predicting cervical lymph node metastasis in patients with HNSCC.

Entosis is a homogeneous cell-in-cell phenomenon and a non-apoptotic cell death process. Tyrosine kinase inhibitors have been used in the treatment of prostate cancer and have already demonstrated efficacy in a clinical setting. The present study investigated the role of entosis in prostate cancer treated with the tyrosine kinase inhibitor nintedanib. Prostate cancer cells were treated with nintedanib in vitro and entosis was observed. Mice xenografts were created to evaluate whether nintedanib is able to induce entosis in vivo. The reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence were performed to investigate whether the entosis pathway is induced by nintedanib. It was also investigated whether entosis can contribute to cell survival and progression under nintedanib stress, and nintedanib was revealed to enhance prostate cancer cell entosis. Nintedanib-induced entosis in prostate cancer cells occurred through phosphoinositide 3-kinase/cell division cycle 42 (CDC42) inhibition, followed by the upregulation of epithelial (E-)cadherin and components of the Rho kinase (ROCK) signaling pathway. In addition, nintedanib-resistant cells exhibiting entosis had a higher invasive ability. In addition, in vivo treatment of mice xenografts with nintedanib also increased the expression of E-cadherin and components of the ROCK signaling pathway. Nintedanib can promote entosis during prostate cancer treatment by modulating the CDC42 pathway. Furthermore, prostate cancer cells acquired nintedanib resistance and survived by activating entosis.

Effects of sevoflurane and propofol anesthesia on pulmonary function, matrix metalloproteinase-9 (MMP-9) and postoperative cognition were compared in patients undergoing simple resection of lower lobe of left lung. Retrospective method was used to analyze 58 cases of lung cancer patients treated by simple resection of lower lobe of left lung in the Second Hospital of Dalian Medical University from October 2016 to October 2017, and they were divided into two groups: Sevoflurane group (n=32) with sevoflurane anesthesia and propofol group (n=26) with propofol anesthesia. In the present study, the moment before induction of anesthesia (T1), before the start of one-lung ventilation (T2), before the end of one-lung ventilation (T3), after closed chest surgery (T4), 24 h after surgery (T5), calculate alveolar-arterial oxygen difference (A-aDO2), respiratory index (RI) and intrapulmonary shunt ratio (Qs/Qt), were compared between the two groups. The serum MMP-9 concentration at T1, T4 and T5 were detected by enzyme linked immunosorbent assay. The cognitive function of two groups was assessed by Mini-Mental State Examination (MMSE) 1 day before surgery and 1 and 10 days after surgery. The A-aDO2 level at T4 in sevoflurane group was significantly higher than that in propofol group (P<0.05). The RI level at T3, T4, the Qs/Qt and the MMP-9 level at T4 in the sevoflurane group was significantly higher than that in the propofol group (P<0.05). The MMSE score in sevoflurane group was significantly lower than that in propofol group 1 and 10 days after surgery (P<0.05). Propofol has little effect on pulmonary function and can decrease inflammatory factor MMP-9. Both sevoflurane and propofol have an effect on cognitive function after lung cancer resection, but propofol can reduce cognitive impairment in patients with lung cancer.

Cisplatin resistance has been a major factor limiting its clinical use as a chemotherapy drug. The present study aimed to investigate whether SET and MYND domain-containing protein 3 (SMYD3), a histone methyltransferase closely associated with tumors can affect the sensitivity of tumors to cisplatin chemotherapy. Real time-qPCR, western blotting, the luciferase reporter, MTT and clonogenic assays were performed to detect the effects of SMYD3 on the chemotherapy capacity of cisplatin. In the present study, SMYD3 exhibited different expression patterns in MCF-7 and T47D breast cancer cells. In addition, this differential expression was associated with tumor cell resistance to cisplatin. Furthermore, SMYD3 knockdown following small interfering RNA transfection increased cisplatin sensitivity, whereas SMYD3 overexpression decreased cisplatin sensitivity. In addition, SMYD3 knockdown synergistically enhanced cisplatin-induced cell apoptosis. SMYD3 expression was downregulated during cisplatin treatment. In addition, transcriptional regulatory activities of SMYD3 3'-untranslated region were also downregulated. These results suggested that SMYD3 may affect cell sensitivity to cisplatin and participate in the development of cisplatin resistance, which is a process that may involve microRNA-124-mediated regulation.

Breast cancer is one of the most common malignancies worldwide and is the second leading cause of cancer-related mortality among females. miRNAs are a class of small noncoding RNAs that are aberrantly expressed in human cancers. Due to their small size and stability, miRNAs have the potential to be efficacious clinical targets. MicroRNA-320a (miR-320a) has been shown to be dysregulated in multiple malignancies. In the present study, the expression levels of miR-320a were investigated in 15 paraffin-embedded in situ breast carcinoma and 130 invasive breast cancer tissues, and the prognostic value for breast cancer patients was assessed. Chromogenic in situ hybridization revealed that 60/130 (46%) invasive breast cancer tissues exhibited high expression levels of miR-320a (staining index score of ≥4). Furthermore, miR-320a staining was found to significantly correlate with tumor size (P=0.046), clinical stage (P<0.001), lymph node metastasis (P<0.001) and distant metastasis (P=0.006). In addition, patients exhibiting low miR-320a expression levels had shorter overall survival times (P<0.001). Univariate and multivariate analyses revealed that miR-320a was an independent prognostic biomarker for invasive breast cancer (hazard ratio, 0.221; 95% confidence interval, 0.050-0.979; P=0.047). Receiver operator characteristic curves revealed that the prognostic value of miR-320a was enhanced when compared with the widely used prognostic biomarkers (estrogen receptor, progesterone receptor and human epidermal growth factor-2) in invasive breast cancer. The results of the present study suggest that miR-320a presents a potential biomarker for the prognosis of invasive breast cancer, and dysregulation of miR-320a may be involved in invasive breast cancer progression.

Kin17 protein is ubiquitously expressed in mammals and is correlated with vital biological functions. However, little is known about the role of Kin17 in the proliferation of hepatocellular carcinoma cells. The aim of the present study was to investigate whether the upregulation of Kin17 can promote the growth of hepatocellular carcinoma cells. A series of assays was performed to study the effect of Kin17 in the proliferation of hepatocellular carcinoma cells in vitro and in vivo. The western blotting results revealed that Kin17 expression was increased in hepatocellular carcinoma tissues compared with that of the corresponding normal tissues. Moreover, ectopic upregulation of Kin17 expression promoted the growth of hepatocellular carcinoma cells in vitro and in vivo. These results indicated that Kin17 is involved in the tumorigenesis of hepatocellular carcinoma, and that Kin17 has the potential to serve as a therapeutic target for hepatocellular carcinoma.

Numerous studies have shown that marital status may be a prognostic factor in various malignancies, but little is known about its effect on duodenal adenocarcinoma. The aim of the present study was to determine the association between marital status and survival in patients with duodenal adenocarcinoma. The Surveillance, Epidemiology and End Results database was utilized to analyze 2,018 patients who had been diagnosed with duodenal adenocarcinoma between January 2004 and December 2015. Kaplan-Meier and Cox regression analyses were also used to determine the impact of marital status on overall survival (OS) and cause-specific survival (CSS). The 5-year OS rate was higher in married patients (32.6%) compared with unmarried (26.8%) patients (P<0.001), as was the 5-year CSS rate (38.8 vs. 33.7%; P<0.001). Multivariate analysis demonstrated that marital status was an independent prognostic factor for duodenal adenocarcinoma, with married patients having improved OS (P<0.001) and CSS (P=0.001) compared with unmarried patients. Subgroup analysis showed that marital status played a role in the survival of patients at American Joint Committee on Cancer Tumor-Node-Metastasis stage I, but not of patients at stages II, III or IV. The survival outcomes for duodenal adenocarcinoma are improved in married patients compared with those in unmarried patients. Therefore, attention should be paid to the impact of social factors and socio-economic factors on unmarried patients, in order to improve their survival outcomes.

Monocytic leukemia-associated antigen-34 (MLAA-34) is a novel monocytic leukemia-associated antigen and a candidate oncogene. The aim of the present study was to investigate the involvement of the MLAA-34 gene in acute myeloid leukemia (AML). MLAA-34 expression level, chromosome location, gene copy number and single nucleotide polymorphisms (SNPs) of 40 patients with AML and 5 healthy volunteers were analyzed by reverse transcription-polymerase chain reaction, fluorescence in situ hybridization and DNA sequencing. The effects of MLAA-34 mutation on overall survival (OS) and progression-free survival (PFS) of patients with AML were also analyzed. MLAA-34 was significantly upregulated in patients with AML when compared with volunteer controls, and this upregulation was associated with a C59T SNP site located in the second exon of MLAA-34. MLAA-34 was mapped to 13q14.2 and no translocation was observed in patients with AML. In addition, this SNP site is affinitive to the well-known molecular markers of AML, including Fms-like tyrosine kinase 3 and DNA methyltransferase 3A, as well as extramedullary lesions, periphery leukocyte numbers, remission and cytogenetic abnormalities of patients with AML. Patients with AML with MLAA-34 C59T mutations had significantly shorter OS and PFS times compared with that of patients without C59T mutations. The present findings indicated that the MLAA-34 C59T mutation was a high-risk factor for recurrence of AML, and may be a candidate target for AML therapy.

The present study aimed to identify differentially expressed inflammatory factors observed in Wilms tumors (WT), and to investigate the association of these factors with clinical stage, pathological type, lymph node metastasis and vascular involvement of WT. Surface-enhanced laser desorption/ionization-time of flight mass spectrometry was performed to screen differentially expressed proteins among WT and normal tissue pairs. Upregulated proteins in WT were separated and purified by solid phase extraction and Tricine SDS-PAGE, respectively. Following in-gel digestion, the peptide mixture was subjected to liquid chromatography mass spectrometry to identify proteins on the basis of their amino acid sequences. Immunohistochemistry was used to confirm the expression of differentially expressed inflammatory proteins. Of the proteins that were upregulated in WT, two proteins with mass/charge (m/z) ratio of 12,138 and 13,462 were identified as macrophage migration inhibitory factor (MIF) and C-X-C motif ligand 7 (CXCL7) chemokine, respectively. The expression of these two proteins was increased in WT compared with adjacent normal tissues and normal renal tissues, and increased with increasing clinical stage. In addition, their expression was significantly increased in patients with unfavorable pathological type, lymph node metastasis and vascular involvement compared with the groups with favorable type, and without lymph node metastasis or vascular involvement (P<0.05). Increased pro-inflammatory MIF and CXCL7 expression in WT is closely associated with the clinical stage, pathological type, lymph node metastasis and vascular involvement, and may represent biomarkers for the clinical diagnosis of WT.

The present study aimed to explore the application of diffusion tensor tractography (DTT) in the preoperative planning and prognostic evaluation of tumors located in the functional areas of the brain. A total of 42 patients diagnosed with intracranial tumors were randomly assigned to either the trial or the control group. DT imaging (DTI) was performed on the basis of preoperative conventional magnetic resonance imaging (MRI) and analyzed for patients in the trial group. Patients in the control group underwent only routine MRI scans. The effect of DTT on the prognosis of patients was evaluated by tumor resection rate and quality of life evaluation using Karnofsky performance score (KPS) comparison between the trial and control groups. There were no significant differences for total tumor removal rate in the trial group (85.71%) compared with that in the control group (71.43%) (P>0.05). The rate of postoperative symptom improvement in the trial group (85.71%) was significantly higher compared with that in the control group (47.62%) (P<0.05). The KPS value of the trial group was significantly higher postoperatively (78.57±17.40) compared with that preoperatively (66.67±16.23) (P<0.05). The KPS value of the control group postoperatively (72.38±19.21) was significantly higher compared with that preoperatively (66.67±16.00) (P<0.05). The postoperative KPS improvement rate [postoperative value-preoperative value)/preoperative value] of the trial group was significantly higher compared with that in the control group. In conclusion, the use of DTT is an effective supplement to traditional MRI, with particular relevance in preoperative planning, particularly for tumors in the functional area of the brain, and can significantly improve the prognostic function of patients.

Osteosarcoma is a malignant bone tumor that commonly occurs in young individuals. It accounts for 10% of solid tumors in those who are 15-19 years old. MicroRNA (miRNA/miR) dysregulation serves a crucial role in the molecular mechanism of osteosarcoma. The present study reported a novel miRNA (miR-1226-3p) and investigated its function in osteosarcoma. miR-1226-3p mimics and miR-1226-3p antisense oligonucleotides were transfected into human osteosarcoma SaOS-2 cells to alter miR-1226-3 expression, while the hFOB 1.19 cell line was used as the control. The apoptosis rate was analyzed using a dead cell apoptosis kit. TNF receptor-associated factor 3 (TRAF3) protein expression was assayed by western blotting. The results of bioinformatics and clinical specimen analyses revealed that higher expression levels of miR-1226-3p were associated with lower survival rates. Additionally, the results of experiments on cultured cells revealed that miR-1226-3p promoted the proliferation of SaOS-2 cells, while miR-1226-3p inhibition decreased cell proliferation and increased apoptosis. Furthermore, it was revealed that miR-1226-3p targeted TRAF3 in SaOS-2 cells. In conclusion, the present study suggested that miR-1226-3p promoted the proliferation of osteosarcoma cells.

Although emerging evidence has indicated that single nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) are associated with susceptibility to gastric cancer, a limited number of studies have revealed the underlying molecular mechanisms. In the present study, the results suggested that miR-1269a rs73239138 has a role in decreasing the risk of gastric cancer. The level of miR-1269a variant expression was significantly downregulated compared with the wild-type miR-1269a in the gastric cells (Fig. 1). Furthermore, overexpression of miR-1269a inhibited apoptosis of gastric cancer cells. Expression of the miR-1269a variant inhibited the function of miR-1269a by increasing the apoptotic rate and the expression of Bik, Bim and Bak was upregulated consistently. In addition, zinc-finger protein 70 (ZNF70) was identified to be a target gene of miR-1269a, which was downregulated by miR-1269a and upregulated by miR-1269a variant. ZNF70 was indicated to exert a role as a tumor suppressor in gastric cancer. To the best our knowledge, the present study for the first time highlights a critical role of miR-1269a variant rs73239138 in decreasing the susceptibility to gastric cancer by downregulating its expression and targeting ZNF70, which promotes apoptosis of gastric cancer cells. This SNP is indicated to serve as a potential biomarker and therapeutic target for gastric cancer.

The aim of the current study was to investigate the role of enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) in the progression of bladder cancer. Human bladder cancer tissue samples were analyzed by immunohistochemistry, and the association between the clinicopathological parameters and EZH2 expression was analyzed. The proliferation, apoptosis and migration ability of the human bladder cancer cell lines E-J and 5637 with or without the EZH2 inhibitor UNC1999 was investigated. The effect of UNC1999 was further explored in a xenograft model of nude mice. The in vivo and in vitro expression levels of EZH2, janus kinase 2, signal transducer and activator of transcription 3 and their phosphorylated forms were examined by western blotting. The expression levels of EZH2, JAK2 and STAT3 were increased in bladder cancer tissue compared with normal adjacent tissue. Furthermore, the expression of EZH2 was increased in tumors with a higher TNM Classification of Malignant Tumors stage and histological grade compared with tumors with a lower stage and grade. The human bladder cancer cell lines E-J and 5637 treated with UNC1999 demonstrated reduced cell proliferation, apoptosis and migration compared with cells treated without UNC1999. Additionally, EZH2 may promote the proliferation and migration of bladder cancer via the JAK2/STAT3 pathway. EZH2 may serve an important role in the proliferation and migration of human bladder cancer cells, and may aid in the development of novel treatment strategies for bladder cancer.

Hepatocellular carcinoma (HCC) is a life-threatening disease that is known to exhibit a poor prognosis. Therefore, it is important to identify an effective drug therapy for the treatment of HCC. Dihydromyricetin (DHM) is a flavonoid compound, isolated from the classical Chinese herb Ampelopsis grossedentata, which exhibits multiple pharmacological activities, including anticancer effects. In this study, the anticancer effect of DHM was investigated in nine different types of HCC cell lines via cell proliferation and immunoassays, as well as apoptosis detection. Two immortalized normal human liver cell lines were utilized to determine hepatotoxicity. The results revealed that DHM significantly inhibited cell proliferation and induced cell apoptosis in the HCC cell lines. However, DHM exhibited no cytotoxicity to normal human hepatic cell lines. Furthermore, it was found that DHM induced cell apoptosis in a p53-dependent manner. DHM upregulated p53 expression, and the upregulation of p53 increased the levels of the cleaved caspase-3 protein, directly inducing cell apoptosis. These results indicate that DHM is a promising candidate for the treatment of HCC.

Leukemia is a leading cause of cancer-related mortality in children worldwide, and multidrug-resistance (MDR) is a main reason for tumor chemotherapy failure. The present study investigated the effects of ADR following incubation with cytokine-induced killer (CIK) cells on reversing MDR in K562/ADR cells. Mononuclear cells were isolated from the peripheral blood of healthy individuals and cultured in vitro in the presence of a combination of cytokines to generate CIK for K562/ADR cell treatment. A decreased level of P-glycoprotein expression and glutathione (GSH), an increased intracellular Rh-123 content, decreased mRNA and protein expression levels of MDR gene 1, MDR-associated protein 1, GSH S-transferase-π, B-cell lymphoma 2 and Survivin, and the decreased phosphorylation of AKT and the transcriptional activity of nuclear factor-κB and activator protein 1 were detected following ADR treatment in CIK co-cultured K562/ADR cells. Additionally, the level of ADR sensitivity and the apoptosis rate were increased in the CIK co-cultured K562/ADR cells. These results indicate that pre-treatment with CIK could reverse the MDR of K562/ADR cells, and that patients would be most likely to benefit from the combination of chemotherapy and CIK therapy.

Diosmetin (DIOS), a flavonoid compound, is abundant in Citrus limon. Emerging studies have shown that DIOS is an effective compound implicated in multiple types of cancer. However, whether DIOS serves a role in hepatocellular carcinoma (HCC) is still obscure. HepG2 cells were used in the present study, and it was observed that DIOS exhibited antitumor activity against liver cancer cells. Western blotting was performed to evaluate cell apoptosis and survival-associated proteins, and the results demonstrated that DIOS treatment resulted in the activation of the p53-dependent apoptosis pathway. Our results revealed that DIOS caused inhibition of the nuclear factor (NF)-κB signaling pathway and downregulation of Notch3 receptor. Furthermore, by using small hairpin RNA-Notch3, it was confirmed that DIOS inhibited the NF-κB signaling pathway by inactivation of Notch3. In conclusion, the present results demonstrated that DIOS triggered cell apoptosis by activation of the p53 signaling pathway and inhibited the NF-κB cell survival pathway by downregulation of Notch3 receptor expression. DIOS is a potential agent for prevention of HCC.

Spleen tyrosine kinase (SYK) has been reported as a potential tumor suppressor in colorectal cancer (CRC). However, the role of alternative splicing of SYK in carcinogenesis remains unclear. In the present study, SYK isoforms were overexpressed in the human CRC HCT 116 cell line using lentiviral expression vectors to investigate the biological functions of full length SYK [SYK(L)] and short form SYK [SYK(S)] in CRC. Real-time cellular analysis and the 5-ethynyl-2-deoxyuridine assay were used to detect the effects of SYK(L) and SYK(S) on cell proliferation. Cell cycle progression and migration were assessed via flow cytometry and Transwell assays, respectively. The results revealed that the recombinant lentivirus with SYK(L) overexpression significantly suppressed the proliferation and metastasis of CRC cells, while SYK(S) overexpression did not. In addition, MTS assays demonstrated that SYK(L) and SYK(S) increased the cellular sensitivity to 5-fluorouracil (5-FU), suggesting that SYK(L) and 5-FU produce a significant synergistic effect on CRC cell proliferation, while SYK(S) has an effect on modulating CRC 5-FU sensitivity. Furthermore, quantitative polymerase chain reaction results revealed that SYK(L) was downregulated in 69% of 26 pairs of CRC and adjacent non-cancerous tissues, whereas SYK(S) exhibited no significant differences between tumor and normal tissues. Overall, the present data provides evidence that SYK(L) is a tumor suppressor in CRC, and both SYK(L) and SYK(S) may serve as important predictors in the chemotherapeutic treatment of CRC.

The cancer stem cell (CSC) theory hypothesizes that CSCs are the cause of tumor formation, recurrence and metastasis. Key to the study of CSCs is their isolation and identification. The present study investigated whether spheroid body-forming cells in the human gastric cancer (GC) MKN-45 cell line are enriched for CSC properties, and also assessed the expression of the candidate CSC markers, octamer-binding transcription factor-4 (OCT4) and adenosine triphosphate-binding cassette transporter G2 (ABCG2) in the MKN-45 spheroid body cells. The MKN-45 cells were plated in a stem cell-conditioned culture system to allow for spheroid body formation. The expression levels of OCT4 and ABCG2 in the spheroid body cells were assessed by qPCR, western blot analysis and immunofluorescence staining, while the tumorigenicity of the spheroid body-forming cells was assessed by in vivo xenograft studies in nude mice. The MKN-45 cells were able to form spheroid bodies when cultured in stem cell-conditioned medium. The spheroid body-forming cells showed a significantly higher (P<0.01) expression of OCT4 and ABCG2 compared with the parental cells. These data suggest that the spheroid body cells from the MKN-45 GC cell line cultured in stem cell-conditioned medium possessed gastric CSC properties. The co-expression of OCT4 and ABCG2 by these cells may represent the presence of a subpopulation of gastric CSCs.

Normal adult mammary stem cells (AMSCs) are promising sources for breast reconstruction, particularly following the resection of breast tumors. However, carcinogenic events can potentially convert normal AMSCs to cancer stem cells, posing a safety concern for the use of AMSCs for clinical tissue regeneration. In the present study, AMSCs and autologous primary breast cancer cells were isolated and compared for their ability to differentiate, their gene expression profile, and their potential to form tumors in vivo. AMSCs were isolated from normal tissue surrounding primary breast tumors by immunomagnetic sorting. The pluripotency of these cells was investigated by differentiation analysis, and gene expression profiles were compared with microarrays. Differentially expressed candidate genes were confirmed by reverse transcription-polymerase chain reaction and western blot analyses. The in vivo tumorigenicity of these cells, compared with low-malignancy MCF-7 cells, was also investigated by xenograft tumor formation analysis. The results revealed that AMSCs isolated from normal tissues surrounding primary breast tumors were positive for the stem cell markers epithelial-specific antigen and keratin-19. When stimulated with basic fibroblast growth factor, a differentiation agent, these AMSCs formed lobuloalveolar structures with myoepithelia that were positive for common acute lymphoblastic leukemia antigen. The gene expression profiles revealed that, compared with cancer cells, AMSCs expressed low levels of oncogenes, including MYC, RAS and ErbB receptor tyrosine kinase 2, and high levels of tumor suppressor genes, including RB transcriptional corepressor 1, phosphatase and tensin homolog, and cyclin-dependent kinase inhibitor 2A. When injected into nude non-obese diabetic/severe combined immunodeficiency-type mice, the AMSCs did not form tumors, and regular mammary ductal structures were generated. The AMSCs isolated from normal tissue adjacent to primary breast tumors had the normal phenotype of mammary stem cells, and therefore may be promising candidates for mammary reconstruction subsequent to breast tumor resection.