Pathological features of gastric‑type endocervical adenocarcinoma: A report of two cases

Gastric-type endocervical adenocarcinoma (GEA) is an uncommon form of uterine cervical adenocarcinoma with an unfavorable prognosis. The tumor consists of glands exhibiting a morphological resemblance to gastric cells and occasionally manifests features akin to pancreaticobiliary mucinous adenocarcinoma. GEA differs from the typical cervical cancer, particularly in its lack of association with the human papillomavirus. Immunophenotypic analysis suggests intestinal differentiation. The present study reports two cases of GEA occurring in postmenopausal individuals who were diagnosed in Lishui Central Hospital (Lishui, China) between January 2015 and January 2023. Microscopic examination revealed cysts lined with mucinous cells within the tumors. Immunohistochemical assays confirmed the positivity of the tumors for cytokeratin 7, mucin (MUC)5AC, and mutant tumor protein p53, while the results were negative for tumor suppressor p16, and in one case for paired box protein 8, consistent with characteristics of mucinous adenocarcinoma originating from the gastrointestinal tract. Programmed death-ligand 1 expression was also negative. The proto-oncogene K-ras was identified using amplification refractory mutation system polymerase chain reaction. Both cases were negative for mutations in codons 12 and 13 of exon 2, codon 61 of exon 3 and codon 146 of exon 4, but were positive for wild-type K-ras. Clinical follow-up revealed a potential association between histopathological features and resistance to chemotherapeutic drugs. The infrequency of this tumor type may contribute to diagnostic challenges.

MiR-29b Downregulation by p53/Sp1 Complex Plays a Critical Role in Bleb Scar Formation After Glaucoma Filtration Surgery

Purpose

To investigate the function and mechanism of tumor protein p53 in pathological scarring after glaucoma filtration surgery (GFS) using human Tenon's fibroblasts (HTFs) and a rabbit GFS model.

Methods

The expression of p53 in bleb scarring after GFS and transforming growth factor-β (TGF-β)-induced HTFs (myofibroblasts [MFs]) was examined by western blot and immunochemical analysis. The interaction between p53 and specificity protein 1 (Sp1) was investigated by immunoprecipitation. The role of p53 and Sp1 in the accumulation of collagen type I alpha 1 chain (COL1A1) and the migration of MFs was evaluated by western blot, quantitative real-time polymerase chain reaction (qRT-PCR), wound healing, and Transwell assay. The regulatory mechanisms among p53/Sp1 and miR-29b were detected via qRT-PCR, western blot, luciferase reporter assay, and chromatin immunoprecipitation assay. The therapeutic effect of mithramycin A, a specific inhibitor of Sp1, on scarring formation was evaluated in a rabbit GFS model.

Results

p53 was upregulated in bleb scar tissue and MFs. p53 and Sp1 form a transcription factor complex that induces the accumulation of COL1A1 and promotes the migration of MFs through downregulation of miR-29b, a known suppressor of COL1A1. The p53/Sp1 axis inhibits miR-29b expression by the direct binding promoter of the miR-29b gene. Mithramycin A treatment attenuated bleb scar formation in vivo.

Conclusions

The p53/Sp1/miR-29b signaling pathway plays a critical role in bleb scar formation after GFS. This pathway could be targeted for therapeutic intervention of pathological scarring after GFS.

Translational Relevance

Our research indicates that inhibition of p53/Sp1/miR-29b is a promising therapeutic strategy for preventing post-GFS pathological scarring.

EGLN1 induces tumorigenesis and radioresistance in nasopharyngeal carcinoma by promoting ubiquitination of p53 in a hydroxylase-dependent manner

Egl-9 Family Hypoxia Inducible Factor 1 (EGLN1) is a proline hydroxylase mediating degradation of hypoxia-inducible factor α (HIFα) through the ubiquitination system. Studies have indicated an essential role for EGLN1 in angiogenesis and tumorigenesis. However, there is no consensus on the regulation of EGLN1 and its mechanism of action on nasopharyngeal carcinoma (NPC). This study explored the association of the expression of EGLN1 with characteristics of NPC tumors and its underlying mechanism. We found that the expression of EGLN1 showed a positive correlation with tumor T classification and clinical staging of patients with NPC. EGLN1 could promote cell proliferation, invasion and migration, and even enhance the cancer stem cells (CSCs) prosperity and radioresistance of NPC cells. Mechanistically, EGLN1 facilitated degradation of tumor protein p53 through the ubiquitination system. This effect could be weakened in the presence of dimethyloxalylglycine (DMOG), suggesting that EGLN1 down-regulated p53 based on its hydroxylase activity. In conclusion, overexpression of EGLN1 promoted oncogenesis and induced a CSC-like phenotype in NPC cells, then enhancing the ability for radioresistance by interacting with p53 in a hydroxylase-dependent manner. Thus, EGLN1 might serve as a potential therapeutic target for NPC.

Different properties of mammary carcinogenesis induced by two chemical carcinogens, DMBA and PhIP, in heterozygous BALB/c Trp53 knockout mice

Chemical carcinogens, such as 7,12-dimethylbenz[a]anthracene (DMBA) and 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), are known to induce mammary carcinomas in mice and rats. In the present study, the phenotypic and genotypic characteristics of carcinogen-induced mammary carcinogenesis in heterozygous BALB/c tumor protein p53 (Trp53) knockout mice were examined with reference to published data surrounding human breast cancer. A significantly accelerated induction of mammary carcinomas was observed following a single dose of DMBA (50 mg/kg of body weight at 7 weeks of age), and a modest acceleration was induced by PhIP (50 mg/kg of body weight) administered by gavage 6 times/2 weeks from 7 weeks of age. DMBA-induced mammary carcinomas were histopathologically characterized by distinct biphasic structures with luminal and myoepithelial cells, as well as a frequent estrogen receptor expression, and PhIP-induced carcinomas with solid/microacinar structures consisted of pleomorphic cells. Of note, DMBA-induced mammary carcinomas were characterized by a HRas proto-oncogene (Hras) mutation at codon 61, and gene/protein expression indicating MAPK stimulation. PhIP-induced lesions were suspected to be caused by different molecular mechanisms, including Wnt/β-catenin signaling and/or gene mutation-independent PI3K/AKT signaling activation. In conclusion, the present mouse mammary carcinogenesis models, induced by a combination of genetic and exogenous factors, may be utilized (such as the DMBA-induced model with Trp53 gene function deficiency as a model of adenomyoepithelioma, characterized by distinct biphasic cell constituents and Hras mutations), but PhIP-induced models are required to further analyze the genetic/epigenetic mechanisms promoting mammary carcinomas.

Aberrant PTEN, PIK3CA, pMAPK, and TP53 expression in human scalp and face angiosarcoma

Angiosarcoma is a rare, highly aggressive malignant tumor originating from endothelial cells that line the lumen of blood or lymphatic vessels. The molecular mechanisms of scalp and face angiosarcoma still need to be elucidated. This study aimed to investigate the expression of phosphatase and tensin homolog (PTEN), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), phosphorylated mitogen-activated kinase-like protein (pMAPK), and tumor protein p53 (TP53) in scalp and face angiosarcoma and to assess tumor tissue apoptosis.The expression and intracellular distribution of PTEN, PIK3CA, pMAPK, and TP53 proteins in 21 specimens of human scalp and face angiosarcoma and 16 specimens of human benign hemangioma were evaluated using immunohistochemistry. Tumor cell apoptosis was assessed by terminal deoxyribonucleotide transferase-mediated dUTP nick end-labeling staining.Significantly lower PTEN but higher PIK3CA, pMAPK, and TP53 immunostaining were detected in the angiosarcoma specimens than in the benign hemangioma specimens(P < .01). The angiosarcoma tissues exhibited significantly higher apoptosis indices than the benign hemangioma tissues (P < .01). The positive expression rates of PIK3CA, pMAPK, and TP53 were correlated with the degree of tumor differentiation in the human scalp and face angiosarcoma.The PI3K, MAPK, and TP53 pathways might be involved in angiosarcoma tumorigenesis in humans and may serve as therapeutic targets for the effective treatment of this malignancy.

Integration of comprehensive genomic profiling, tumor mutational burden, and PD-L1 expression to identify novel biomarkers of immunotherapy in non-small cell lung cancer

OBJECTIVES

This study aimed to explore the novel biomarkers for immune checkpoint inhibitor (ICI) responses in non-small cell lung cancer (NSCLC) by integrating genomic profiling, tumor mutational burden (TMB), and expression of programmed death receptor 1 ligand (PD-L1).

MATERIALS AND METHODS

Tumor and blood samples from 637 Chinese patients with NSCLC were collected for targeted panel sequencing. Genomic alterations, including single nucleotide variations, insertions/deletions, copy number variations, and gene rearrangements, were assessed and TMB was computed. TMB-high (TMB-H) was defined as ≥10 mutations/Mb. PD-L1 positivity was defined as ≥1% tumor cells with membranous staining. Genomic data and ICI outcomes of 240 patients with NSCLC were derived from cBioPortal.

RESULTS

EGFR-sensitizing mutations, ALK, RET, and ROS1 rearrangements were associated with lower TMB and PD-L1+/TMB-H proportions, whereas KRAS, ALK, RET, and ROS1 substitutions/indels correlated with higher TMB and PD-L1+/TMB-H proportions than wild-type genotypes. Histone-lysine N-methyltransferase 2 (KMT2) family members (KMT2A, KMT2C, and KMT2D) were frequently mutated in NSCLC tumors, and these mutations were associated with higher TMB and PD-L1 expression, as well as higher PD-L1+/TMB-H proportions. Specifically, patients with KMT2C mutations had higher TMB and PD-L1+/TMB-H proportions than wild-type patients. The median progression-free survival (PFS) was 5.47 months (95% CI 2.5-NA) in patients with KMT2C mutations versus 3.17 months (95% CI 2.6-4.27) in wild-type patients (p = 0.058). Furthermore, in patients with NSCLC who underwent ICI treatment, patients with TP53/KMT2C co-mutations had significantly longer PFS and greater durable clinical benefit (HR: 0.48, 95% CI: 0.24-0.94, p = 0.033). TP53 mutation combined with KMT2C or KRAS mutation was a better biomarker with expanded population benefit from ICIs therapy and increased the predictive power (HR: 0.46, 95% CI: 0.26-0.81, p = 0.007).

CONCLUSION

We found that tumors with different alterations in actionable target genes had variable expression of PD-L1 and TMB in NSCLC. TP53/KMT2C co-mutation might serve as a predictive biomarker for ICI responses in NSCLC.

IMPLICATIONS FOR PRACTICE

Cancer immunotherapies, especially immune checkpoint inhibitors (ICIs), have revolutionized the treatment of non-small cell lung cancer (NSCLC); however, only a proportion of patients derive durable responses to this treatment. Biomarkers with greater accuracy are highly needed. In total, 637 Chinese patients with NSCLC were analyzed using next-generation sequencing and IHC to characterize the unique features of genomic alterations and TMB and PD-L1 expression. Our study demonstrated that KMT2C/TP53 co-mutation might be an accurate, cost-effective, and reliable biomarker to predict responses to PD-1 blockade therapy in NSCLC patients and that adding KRAS to the biomarker combination creates a more robust parameter to identify the best responders to ICI therapy.

Serum Response Factor (SRF) Drives the Transcriptional Upregulation of the MDM4 Oncogene in HCC

Different molecular mechanisms support the overexpression of the mouse double minute homolog 4 (MDM4), a functional p53 inhibitor, in human hepatocellular carcinoma (HCC). However, the transcription factors (TFs) leading to its transcriptional upregulation remain unknown. Following promoter and gene expression analyses, putative TFs were investigated using gene-specific siRNAs, cDNAs, luciferase reporter assays, chromatin immunoprecipitation, and XI-011 drug treatment in vitro. Additionally, MDM4 expression was investigated in SRF-VP16iHep transgenic mice. We observed a copy-number-independent upregulation of MDM4 in human HCCs. Serum response factor (SRF), ELK1 and ELK4 were identified as TFs activating MDM4 transcription. While SRF was constitutively detected in TF complexes at the MDM4 promoter, presence of ELK1 and ELK4 was cell-type dependent. Furthermore, MDM4 was upregulated in SRF-VP16-driven murine liver tumors. The pharmacological inhibitor XI-011 exhibited anti-MDM4 activity by downregulating the TFs driving MDM4 transcription, which decreased HCC cell viability and increased apoptosis. In conclusion, SRF drives transcriptional MDM4 upregulation in HCC, acting in concert with either ELK1 or ELK4. The transcriptional regulation of MDM4 may be a promising target for precision oncology of human HCC, as XI-011 treatment exerts anti-MDM4 activity independent from the MDM4 copy number and the p53 status.

Association of lncRNA-p53 regulatory network (lincRNA-p21, lincRNA-ROR and MALAT1) and p53 with the clinicopathological features of colorectal primary lesions and tumors

Colorectal cancer (CRC) is a common intestinal cancer with a high mortality rate. Early detection of this type of cancer is fundamental to the prevention of the disease, which results in improved survival rates. In the human colon tissue, transition from normal epithelium to adenoma is considered to be caused by unknown molecular incidents occurring over 5-10 years. The detection of CRC has proved problematic when in the early stages of disease. In addition, identifying suitable biomarkers for the detection of CRC progress in patients remains one of the most significant challenges. Long non-coding RNAs have been demonstrated to contribute to the promotion of CRC. The aim of the present study was to investigate the clinical and biological significance of long intergenic non-coding (linc)RNA-p21, lincRNA-regulator of reprogramming (ROR) and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the colon tumor and polyp tissue, and the association that these have with the expression of p53 at the mRNA level. Neoplastic and paired adjacent normal tissue samples were obtained from 72 patients (46 polyps and 26 tumors). Reverse transcription-quantitative PCR was performed to determine the relative fold changes in the expression of lincRNA-p21, lincRNA-RoR, MALAT1 and p53 in the samples. A significant association was observed between the levels of MALAT1 and p53 in neoplasm tissues (R=0.073; P<0.05). The relative expression of the MALAT1 gene revealed a statistically significant difference between the different polyp types and number of polyps (P=0.0028 and 0.022, respectively). Adjuvant therapy in patients with tumors revealed an association between the levels of lincRNA-ROR and lincRNA-p21 expression (P=0.015 and 0.038, respectively). MALAT1 may be selected as an early detection biomarker for CRC. Furthermore, lincRNA-ROR and lincRNA-p21 may serve as prognostic and therapeutic biomarkers in patients with CRC.

Activating p53 family member TAp63: A novel therapeutic strategy for targeting p53-altered tumors

BACKGROUND

Over 96% of high-grade ovarian carcinomas and 50% of all cancers are characterized by alterations in the p53 gene. Therapeutic strategies to restore and/or reactivate the p53 pathway have been challenging. By contrast, p63, which shares many of the downstream targets and functions of p53, is rarely mutated in cancer.

METHODS

A novel strategy is presented for circumventing alterations in p53 by inducing the tumor-suppressor isoform TAp63 (transactivation domain of tumor protein p63) through its direct downstream target, microRNA-130b (miR-130b), which is epigenetically silenced and/or downregulated in chemoresistant ovarian cancer.

RESULTS

Treatment with miR-130b resulted in: 1) decreased migration/invasion in HEYA8 cells (p53 wild-type) and disruption of multicellular spheroids in OVCAR8 cells (p53-mutant) in vitro, 2) sensitization of HEYA8 and OVCAR8 cells to cisplatin (CDDP) in vitro and in vivo, and 3) transcriptional activation of TAp63 and the B-cell lymphoma (Bcl)-inhibitor B-cell lymphoma 2-like protein 11 (BIM). Overexpression of TAp63 was sufficient to decrease cell viability, suggesting that it is a critical downstream effector of miR-130b. In vivo, combined miR-130b plus CDDP exhibited greater therapeutic efficacy than miR-130b or CDDP alone. Mice that carried OVCAR8 xenograft tumors and were injected with miR-130b in 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) liposomes had a significant decrease in tumor burden at rates similar to those observed in CDDP-treated mice, and 20% of DOPC-miR-130b plus CDDP-treated mice were living tumor free. Systemic injections of scL-miR-130b plus CDDP in a clinically tested, tumor-targeted nanocomplex (scL) improved survival in 60% and complete remissions in 40% of mice that carried HEYA8 xenografts.

CONCLUSIONS

The miR-130b/TAp63 axis is proposed as a new druggable pathway that has the potential to uncover broad-spectrum therapeutic options for the majority of p53-altered cancers.

p53 Phosphomimetics Preserve Transient Secondary Structure but Reduce Binding to Mdm2 and MdmX

The disordered p53 transactivation domain (p53TAD) contains specific levels of transient helical secondary structure that are necessary for its binding to the negative regulators, mouse double minute 2 (Mdm2) and MdmX. The interactions of p53 with Mdm2 and MdmX are also modulated by posttranslational modifications (PTMs) of p53TAD including phosphorylation at S15, T18 and S20 that inhibits p53-Mdm2 binding. It is unclear whether the levels of transient secondary structure in p53TAD are changed by phosphorylation or other PTMs. We used phosphomimetic mutants to determine if adding a negative charge at positions 15 and 18 has any effect on the transient secondary structure of p53TAD and protein-protein binding. Using a combination of biophysical and structural methods, we investigated the effects of single and multisite phosphomimetics on the transient secondary structure of p53TAD and its interaction with Mdm2, MdmX, and the KIX domain. The phosphomimetics reduced Mdm2 and MdmX binding affinity by 3–5-fold, but resulted in minimal changes in transient secondary structure, suggesting that the destabilizing effect of phosphorylation on the p53TAD-Mdm2 interaction is primarily electrostatic. Phosphomimetics had no effect on the p53-KIX interaction, suggesting that increased binding of phosphorylated p53 to KIX may be influenced by decreased competition with its negative regulators.

Targeted OMA1 therapies for cancer

The mitochondrial inner membrane proteins OMA1 and OPA1 belong to the BAX/BAK1-dependent apoptotic signaling pathway, which can be regulated by tumor protein p53 and the prohibitins PHB and PHB2 in the context of neoplastic disease. For the most part these proteins have been studied separate from each other. Here, I argue that the OMA1 mechanism of action represents the missing link between p53 and cytochrome c release. The mitochondrial fusion protein OPA1 is cleaved by OMA1 in a stress-dependent manner generating S-OPA1. Excessive S-OPA1 can facilitate outer membrane permeabilization upon BAX/BAK1 activation through its membrane shaping properties. p53 helps outer membrane permeabilization in a 2-step process. First, cytosolic p53 activates BAX/BAK1 at the mitochondrial surface. Then, in a second step, p53 binds to prohibitin thereby releasing the restraint on OMA1. This activates OMA1, which cleaves OPA1 and promotes cytochrome c release. Clearly, OMA1 and OPA1 are not root causes for cancer. Yet many cancer cells rely on this pathway for survival, which can explain why loss of p53 function promotes tumor growth and confers resistance to chemotherapies.

Antitumorigenic effect of damnacanthal on melanoma cell viability through p53 and NF-κB/caspase-3 signaling pathways

Melanoma is highly malignant, particularly prone to metastasizing to the skin. The incidence of melanoma varies markedly between countries, and is relatively low in China. The aim of the present study was to investigate the antitumorigenic effect of damnacanthal on melanoma cells, and its molecular mechanism. MUM-2B cells were treated with 0-20 µM damnacanthal for 12, 24 and 48 h. In vitro, it was demonstrated that damnacanthal inhibited proliferation and promoted apoptosis of melanoma cells in a dose- and time-dependent manner. Damnacanthal treatment increased caspase-3/8 and 9 activity, and promoted B-cell lymphoma 2-associated X protein, tumor protein p53 (p53) and p21 protein expression levels in melanoma cells. Damnacanthal treatment also resulted in downregulated nuclear factor-κB (NF-κB), cyclin D and cyclin E protein expression in melanoma cells. In conclusion, the results of the present study demonstrated that the antitumorigenic activity of damnacanthal on melanoma cells is executed via the p53/p21 and NF-κB/cyclin/ caspase-3 signaling pathways.

B-cell lymphoma 2 is associated with advanced tumor grade and clinical stage, and reduced overall survival in young Chinese patients with colorectal carcinoma

The development of biomarkers that accurately and reliably detect colorectal cancer is a promising approach for colorectal cancer screening. Therefore, the objective of the present study was to evaluate the protein expression of α-methylacyl-CoA racemase (P504S/AMACR), tumor protein p53 (p53), B-cell lymphoma 2 (Bcl-2) and Ki-67/mindbomb E3 ubiquitin protein ligase 1 (MIB-1) in a population of Chinese patients with colorectal carcinoma. Colorectal tumors with matched normal tissue margins were collected from 148 surgical patients, and the demographic and clinical characteristics were collected. Immunohistochemical staining and western blot analysis of P504S/AMACR, p53, Bcl-2 and Ki-67/MIB-1 were conducted. Statistical analyses were used to compare protein expression in the colorectal tumors and matched normal tissue margins and to identify any associations between them and various clinicopathological parameters. Survival analyses were performed using the Kaplan-Meier method. In the present study, immunohistochemistry and western blot analysis revealed significantly higher expression of all four proteins in colorectal tumors compared with matched normal tissue margins (P<0.001). Spearman's rank correlation analysis revealed that Bcl-2 expression was negatively correlated with pathological grade and Tumor-Node-Metastasis (TNM) stage (-0.827 and -0.388, respectively; P<0.05). Bcl-2 expression was revealed to be a significant prognostic indicator of colorectal carcinoma [relative risk (95% CI), 0.703 (0.552-0.895); P<0.05]. The log-rank test revealed a significant association between low Bcl-2 expression and reduced overall survival (P=0.039), as well as a significant association between older age (>55 years) and reduced overall survival (P<0.001) in Chinese patients with colorectal carcinoma. In conclusion, low expression of Bcl-2 is significantly correlated with advanced pathological grade and TNM stage and is a prognostic indicator of reduced overall survival in young Chinese patients with colorectal carcinoma.

p53 positively regulates the expression of cancer stem cell marker CD133 in HCT116 colon cancer cells

Colon cancer stem cells (CSCs), which are highly capable of self-renewal and proliferation, are involved in colon tumorigenesis and response to therapy. CD133 is considered the most robust surface marker for colorectal cancer stem cells. Although the TP53 gene is frequently mutated in colon cancer, it remains not fully understood whether and how tumor protein p53 (p53) is associated with CD133 expression in colon cancer cells. In the present study, the expression of the CSC biomarker CD133 was investigated in terms of p53 status in colorectal carcinoma HCT116 cells. p53 wild-type HCT116 (HCT116 p53^+/+) and depleted HCT116 (HCT116 p53^-/-) cells were used throughout this study. Cells carrying the CSC biomarkers CD133 and CD44 were examined by flow cytometry. A dual-luciferase reporter assay was employed to further confirm the transcriptional regulation of the CD133 promoter by p53. The results demonstrated that there was a significant difference in the % of CD133-positive cells between the HCT116 p53^+/+ cell line (84.84±0.05%) and the HCT116 p53^-/- cell line (4.13±0.02%). The mRNA expression levels of CD133 in HCT116 p53^+/+ cells were also significantly higher compared with HCT116 p53^-/- cells. Knockdown of p53 by specific small interfering RNA greatly reduced the expression of CD133 in HCT116 p53^+/+ cells. Transcription factor binding site analysis indicated that there are several p53 binding elements in the CD133 promoter region. A dual-luciferase reporter assay further demonstrated the transcriptional activation of CD133 promoter by p53. In conclusion, these results suggest that p53 positively regulates the expression of CSC marker CD133 in the HCT116 human colon colorectal cancer cell line. p53 may be involved in the initiation and maintenance of colorectal cancer stem cells through regulating the expression of CD133.

The family of apoptosis-stimulating proteins of p53 is dysregulated in colorectal cancer patients

The apoptosis-stimulating protein of p53 (ASPP) family is a newly identified family protein including ASPP1, ASPP2 and inhibitor of ASPP (iASPP), by which the tumor protein 53 (TP53)-mediated apoptotic process is selectively regulated. Downregulation of ASPP1/ASPP2 and upregulation of iASPP were revealed to be associated with a poor prognosis and metastasis in several types of cancer. However, to the best of our knowledge, the expression of ASPP in colorectal cancer (CRC) has not previously been investigated. The present study analyzed ASPP expression in human CRC tissues with multiple clinical and pathological profiles. A total of 41 patients diagnosed with CRC were enrolled in the present study. The expression of ASPP was detected by immunohistochemistry, immunofluorescence and reverse transcription-quantitative polymerase chain reaction. In addition, the variation in ASPP expression was examined in a number of pathological groups. The associations among ASPP expression, and the expression of TP53, plasma carcinoembryonic antigen (CEA) levels and α-fetoprotein (AFP) levels were also investigated. ASPP1 and ASPP2 expression was significantly reduced, while iASPP expression was elevated in CRC samples compared with expression in adjacent non-cancerous tissues. Downregulation of ASPP1 was detected in the TP53-positive group compared with the TP53-negative group. The increase in iASPP expression was correlated with the grade of malignancy, but not with regional lymph node status or metastases. The expression of ASPP2 was negatively correlated with plasma CEA levels. The results of the present study, not only enrich CRC epidemic and pathological data, but also provide valuable indices for CRC clinical treatment and prognosis.

Upregulation of let-7f-5p promotes chemotherapeutic resistance in colorectal cancer by directly repressing several pro-apoptotic proteins

Colorectal cancer (CRC) is one of the most frequently occurring primary malignant tumors worldwide. Chemotherapeutic resistance is a major clinical problem in the treatment of CRC. Therefore, it is of great importance to investigate novel biomarkers that may predict chemoresistance and facilitate the development of individualized treatment for patients with CRC. The present study reported that let-7f-5p expression was elevated in chemotherapy-resistant CRC tissues compared with chemotherapy-sensitive tissues. Furthermore, upregulating let-7f-5p increased the expression levels of the anti-apoptotic proteins, B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra large (Bcl-xL), and decreased the activity of caspase-3 and caspase-9 in CRC cells. By contrast, downregulating let-7f-5p yielded the opposite effect. Notably, the results indicated that let-7f-5p promoted chemotherapeutic resistance by directly repressing the expression of several pro-apoptotic proteins, including tumor protein p53, tumor protein p53-inducible nuclear protein 1, tumor protein p53-inducible nuclear protein 2 and caspase-3. Therefore, a novel mechanism by which let-7f-5p enhances the resistance of CRC cells to chemotherapeutics has been revealed, indicating that silencing let-7f-5p may become an effective therapeutic strategy against CRC.

Human corticotrophin releasing factor inhibits cell proliferation and promotes apoptosis through upregulation of tumor protein p53 in human glioma

Corticotropin-releasing factor (CRF) and its receptors have been detected in numerous tumors and have an important role in tumorigenesis and proliferation. However, the role of these peptides has not been established in human glioma and malignant glioma cell lines. The present study evaluated for the first time, the expression of CRF receptor 1 (CRFR1) in 35 human glioma samples, 13 normal brain tissues and human U87 glioma cells using immunohistochemistry, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Levels of CRFR1 were identified to be significantly increased in human glioma and U87 cells and higher levels of CRFR1 were observed in glioma tissues of higher grade. The biological functions of human CRF (hCRF) on U87 cells glioma cells were investigated by cell counting, a bromodeoxyuridine assay and flow cytometry. The U87 cells under hCRF treatment exhibited reduced proliferation, increased apoptosis and a cell cycle arrest in S and G2/M phase. The tumor protein p53 (p53) gene may participate in the activation of hCRF via CRFR1 in U87 cells, therefore p53 mRNA and protein were evaluated using RT-qPCR and western blot analysis. Finally, the present results suggest that hCRF inhibits proliferation and induces cell-cycle arrest and apoptosis in U87 cells via the CRFR1-mediated p53 signaling pathway. Therefore, the present study also suggests that hCRF may be used therapeutically, and CRFR1 may be a putative therapeutic target for human glioma.

miR-1269 promotes cell survival and proliferation by targeting tp53 and caspase-9 in lung cancer

Background and aim

Lung cancer is the leading cause of cancer death worldwide. In this study, we aim to elucidate the role of miR-1269 in the pathogenesis of lung cancer.

Methods and results

From the results of analyses using The Cancer Genome Atlas (TCGA) database, we noted the expression of miR-1269 was increased in lung cancer tissue. miR-1269 expression was detected in both the normal adjacent lung tissue and in the tumorous lung tissue of lung cancer patients, and miR-1269 was more highly expressed in the tumors. High expression of miR-1269 correlated with patients’ tumor stage and lymph node metastasis. A Cell Counting Kit-8 (CCK8) analysis and a cloning formation assay showed that overexpression of miR-1269 significantly promoted the growth of A549 cells, and that a lower expression of miR-1269 significantly increased cell apoptosis. We used the TargetScan 6.2 Database to predict the potential targets of miR-1269, and a luciferase activity assay was used to determine the direct interaction between miR-1269, tumor protein p53 (TP53), and caspase-9. Results from Western blots and real-time PCR showed that overexpression of miR-1269 significantly inhibited TP53 and caspase-9 expression. In addition, caspase-3 activity was found to decrease in a miR-1269 mimic group. The results showed that gene silencing of TP53 and caspase-9 significantly inhibited A549 cell growth and promoted cell apoptosis. The results also showed that the inhibition of miR-1269 and caspase-9 expression inhibited cell apoptosis. Immunohistochemistry (IHC) results demonstrated that TP53 and caspase-9 were expressed in low levels in tumor tissues, and that an inverse correlation exists between miR-1269 expression levels and TP53 or caspase-9 expression levels.

Conclusion

These results demonstrate that miR-1269 promotes cell survival and proliferation by targeting TP53 and caspase-9 in lung cancer.

Tumor Protein p53 (TP53) Gene and Left Main Coronary Artery Disease

Patients with left main (LM) coronary artery disease (CAD) are at the highest risk of cardiovascular events. We evaluated possible gene polymorphisms of tumor protein 53 ( TP53, rs1042522, p.Arg72Pro) that can differentiate LM-CAD from patients with more peripheral CAD (MP-CAD) and healthy participants (control group) in 520 individuals (LM-CAD, n = 175; MP-CAD, n = 185; and control group, n = 160). Patients with LM-CAD had the lowest Arg/Arg genotype frequency (36.0%) compared with the MP-CAD (57.3%) and control groups (61.9%), P < .001 for both comparisons. Similarly, the Arg allele was more frequent in the control group than in patients with MP-CAD (78.8% vs 73.2%; P = .007) and LM-CAD (78.8% vs 64.0%; P < .001). The Arg/Pro genotype was more frequent in the LM-CAD group compared with the MP-CAD and control groups (56.0, 31.9, and 33.8, respectively, P < .001 for both comparisons). Furthermore, the frequency of Arg/Arg genotypes was the lowest in the LM-CAD group compared with the MP-CAD and control groups. Knowing that TP53 is an antioncogene protein that acts as a tumor suppressor and regulator of apoptosis, the lowest frequency of Arg/Arg genotype observed in these high-risk patients may indicate lower protection from the atherosclerosis process. Replication studies are needed to evaluate this association.

Bufadienolides induce p53-mediated apoptosis in esophageal squamous cell carcinoma cells in vitro and in vivo

Bufadienolides are a type of cardiotonic steroids isolated from the skin and parotid venom glands of the toad Bufo bufo gargarizans Cantor, and exhibit wide-spectrum anticancer activities. However, the effects and mechanisms of bufadienolides on esophageal squamous cell carcinoma (ESCC) cells remain unknown. In the present study, the anticancer activities of two bufadienolides, bufotalin and bufalin, were examined in vitro and in vivo. The results demonstrated that bufotalin and bufalin effectively inhibited the viability of ESCC cells, with half-maximal inhibitory concentration (IC₅₀) values of 0.8–3.6 µM. However, bufotalin and bufalin exhibited lower toxicity towards Het-1A human esophageal squamous cells, indicating their high selectivity towards cancer cells. Mechanistic studies revealed that bufotalin effectively induced ESCC cell apoptosis, as characterized by DNA fragmentation and nuclear condensation, which was primarily mediated through activation of caspase family members. In addition, treatment of ESCC cells with bufotalin markedly activated tumor protein p53 (p53) phosphorylation. Transfection of cells with p53 small interfering RNA markedly inhibited bufotalin-induced p53 phosphorylation and significantly inhibited bufotalin-induced cell apoptosis. Furthermore, bufotalin demonstrated in vivo anticancer efficacy in a tumor-bearing nude mice model, where bufotalin effectively inhibited Eca-109 xenograft tumor growth in a time- and dose-dependent manner, through activation of the p53 signaling pathway. Collectively, the results from the present study suggested that bufadienolides exert anticancer effects against ESCC by regulating the p53 signaling pathway.

Cnidium officinale Makino extract induces apoptosis through activation of caspase-3 and p53 in human liver cancer HepG2 cells

A number of diverse studies have reported the anticancer properties of Cnidium officinale Makino (CO). However, the apoptotic effect of this traditional medicinal herb in human hepatocellular carcinoma cells (HepG2) remains to be elucidated. Therefore, the present study investigated the ability of CO to reduce cell viability through apoptotic pathways. Cell viability was determined using the 2,3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide assay. CO extract-induced apoptosis in HepG2 cells was assessed by Hoechst 33258 staining. The cell cycle was monitored using fluorescence-activated cell sorting analysis with propidium iodide staining. Furthermore, the present study explored whether various signaling molecules associated with HepG2 cell death were affected by CO treatment, including caspase-3, B-cell lymphoma 2 (Bcl-2), tumor protein p53 (p53), cyclin-dependent kinase 4 (CDK4) and cyclin D. The expression levels of these genes were examined by reverse-transcription polymerase chain reaction and western blotting. The expression levels of caspase-3 and p53 were upregulated with CO extract treatment, whereas those of Bcl-2, CDK4 and cyclin D were significantly downregulated. Cleaved caspase-3 expression was upregulated following treatment with CO extract in a dose-dependent manner. Collectively, the data suggest that CO extract has the potential to induce apoptosis of HepG2 cells and may act by suppressing the cell cycle, which leads to caspase-3 cleavage and p53 signaling.

Upregulation of maspin expression in human cervical carcinoma cells by transforming growth factor β1 through the convergence of Smad and non-Smad signaling pathways

Mammary serine protease inhibitor (maspin), encoded by the serpin family B member 5 gene, serves as a tumor suppressor through the inhibition of cancer cell invasion and metastasis. Paradoxically, maspin levels are upregulated in a number of types of malignant cells. Therefore, the regulation of maspin expression may depend on the genetic or epigenetic background and the specific microenvironment of carcinoma cells. In the present study, it was demonstrated that transforming growth factor β1 (TGF-β1) induced maspin expression at the transcript and protein levels in the human cervical carcinoma HeLa and human oral squamous carcinoma HSC4 cell lines. The inhibition of the mothers against decapentaplegic homolog (Smad)-dependent pathway by a Smad3-specific inhibitor suppressed maspin induction by TGF-β1 in HeLa cells. Inhibition of the non-Smad pathway by pretreatment with the mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor U0126, or the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB202190, attenuated the effect of TGF-β1 on maspin upregulation, whereas pretreatment with pyrrolidine dithiocarbamate (a nuclear factor κB inhibitor), wortmannin (a phosphoinositide 3-kinase inhibitor) or SP600125 (a c-Jun N-terminal kinase inhibitor) did not. Notably, none of these inhibitors eliminated the TGF-β1-induced phosphorylation of Smad2. In addition, mutations at p53-binding sites in the maspin promoter suppressed TGF-β1-induced maspin expression, indicating the necessity of intact p53-binding sites on the maspin promoter. In summary, the induction of maspin expression in HeLa cells requires the convergence of TGF-β1-induced Smad and non-Smad signaling pathways, in which the latter acts via the intermediate signaling molecules MEK1/2 and p38 MAPK.

Combining Oncolytic Virotherapy with p53 Tumor Suppressor Gene Therapy

Oncolytic virus (OV) therapy utilizes replication-competent viruses to kill cancer cells, leaving non-malignant cells unharmed. With the first U.S. Food and Drug Administration-approved OV, dozens of clinical trials ongoing, and an abundance of translational research in the field, OV therapy is poised to be one of the leading treatments for cancer. A number of recombinant OVs expressing a transgene for p53 (TP53) or another p53 family member (TP63 or TP73) were engineered with the goal of generating more potent OVs that function synergistically with host immunity and/or other therapies to reduce or eliminate tumor burden. Such transgenes have proven effective at improving OV therapies, and basic research has shown mechanisms of p53-mediated enhancement of OV therapy, provided optimized p53 transgenes, explored drug-OV combinational treatments, and challenged canonical roles for p53 in virus-host interactions and tumor suppression. This review summarizes studies combining p53 gene therapy with replication-competent OV therapy, reviews preclinical and clinical studies with replication-deficient gene therapy vectors expressing p53 transgene, examines how wild-type p53 and p53 modifications affect OV replication and anti-tumor effects of OV therapy, and explores future directions for rational design of OV therapy combined with p53 gene therapy.

Detection of p53 and Bcl-2 expression in cutaneous hemangioma through the quantum dot technique

Hemangioma is one of the most common types of infantile vascular benign tumor. The aim of the present study was to investigate the role of B-cell lymphoma 2 (Bcl-2) and tumor protein p53 (p53) in the proliferation and apoptosis of hemangioma cells. A total of 38 paraffin-embedded hemangioma specimens (16 males and 22 females) and another 5 paraffin-embedded healthy surrounding tissue samples, collected between January 2007 and December 2010, were obtained from the Department of Pathology at Renmin Hospital of Wuhan University (Wuhan, China). Immunohistochemistry, hematoxylin and eosin staining, and quantum dot double staining were used to detect the expression of proliferating cell nuclear antigen (PCNA), Bcl-2 and p53 in hemangioma and healthy surrounding skin tissue samples. All hemangioma specimens were classified into proliferative or the involuting stage hemangioma according to Mulliken's criteria and their expression of PCNA. The results of the quantum dot double staining were analyzed using a multi-spectral imaging system. One-way analysis of the variance and the Student-Newman-Keuls q test were performed to statistically analyze the data. There were 24 cases of proliferative stage and 14 cases of involuting stage hemangioma among the specimens. Immunohistochemical analysis results indicated a high expression of Bcl-2 and p53 in proliferative stage hemangioma tissue samples, and low expression in involuting stage hemangioma and healthy tissue samples. Statistical analysis of the results from quantum dot double staining demonstrated that the expression of Bcl-2 and p53 in proliferative hemangioma was significantly increased compared with that in involuting stage specimens (P<0.05) and healthy tissue samples (P<0.05). No significant difference in Bcl-2 and p53 expression was identified between the involuting hemangioma and healthy surrounding tissue samples. The higher expression of Bcl-2 and p53 in proliferative hemangioma suggests that Bcl-2 may cause an imbalance between endothelial cell proliferation and apoptosis through the inhibition of endothelial cell apoptosis. Furthermore, p53 may promote the proliferation of endothelial cells in proliferative hemangioma.

Advanced glycation end products influence oral cancer cell survival via Bcl-xl and Nrf-2 regulation in vitro

An irreversible non-enzymatic reaction between carbohydrates and proteins results in the formation of advanced glycation end products (AGEs). AGEs have been demonstrated to be a risk factor of complications in patients with diabetes mellitus (DM). Previous studies have suggested that patients with DM exhibit a higher rate of metastasis of oral cancer and a lower cancer-associated survival rate. The receptor for AGEs (RAGE) has been associated with angiogenesis and an increase in cancer malignancy. Previous studies have suggested that AGE-RAGE regulates cell migration via extracellular signal-regulated kinase (ERK) phosphorylation. Nuclear factor-erythroid 2-related factor 2 (Nrf-2) is associated with the regulation of tumor protein p53 (p53) and the apoptotic response of oral cancer cells. AGEs are associated with oral cancer; however, the mechanism underlying this association remains to be elucidated. The present study hypothesized that AGEs regulate Nrf-2 and downstream pathways through ERK phosphorylation. The results of the current study demonstrated that AGEs inhibit the expression of Nrf-2, p53 and Bcl-2 associated × apoptosis regulator, and increase the expression of apoptosis regulator Bcl-x protein. The effect of AGEs was inhibited through the use of the PD98059. The present study demonstrated that AGEs regulate the downstream pathways Nrf-2 and Bcl-xl via ERK phosphorylation. It is suggested that AGEs regulate the survival of oral cancer cells via Nrf-2 and Bcl-xl through p53 regulation, which explains the poor prognosis of patients with DM who have oral cancer.

Bioinformatics analysis of the prognostic value of Tripartite Motif 28 in breast cancer

Tripartite motif containing 28 (TRIM28) is a transcriptional regulator acting as an essential corepressor for Krüppel-associated box zinc finger domain-containing proteins in multiple tissue and cell types. An increasing number of studies have investigated the function of TRIM28; however, its prognostic value in breast cancer (BC) remains unclear. In the present study, the expression of TRIM28 was identified to be significantly higher in cancerous compared with healthy tissue samples. Furthermore, it was demonstrated that TRIM28 expression was significantly correlated with several clinicopathological characteristics of patients with BC, such as p53 mutation, tumor recurrence and Elston grade of the tumor. In addition, a protein-protein interaction network was created to illustrate the interactions of TRIM28 with other proteins. The prognostic value of TRIM28 in patients with BC was investigated using the Kaplan-Meier Plotter database, which revealed that high expression of TRIM28 is a predictor of poor prognosis in patients with BC. In conclusion, the results of the present study indicate that TRIM28 provides a survival advantage to patients with BC and is a novel prognostic biomarker, in addition to being a therapeutic target for the treatment of BC.

t(14;18)(q32;q21) in chronic lymphocytic leukemia patients: Report of two cases and a literature review

The chromosomal abnormality t(14;18)(q32;q21) is most commonly associated with germinal center-derived B-cell lymphomas, particularly follicular lymphoma (FL). Generally, it is considered a hallmark of FL. The t(14;18)(q32;q21) translocation is rare in chronic lymphocytic leukemia (CLL) and its prognostic significance remains unclear. In the present study, two cases of CLL with t(14;18)(q32;q21) were diagnosed using conventional cytogenetic analysis and fluorescence in situ hybridization. Both patients presented with leukemia and the morphological features and immunophenotypes were typical of CLL. Case 2 underwent a further lymph node biopsy, which established a diagnosis of CD5^- CLL/small lymphocyte lymphoma. In addition to t(14;18)(q32;q21), trisomy 12 was identified in the same clone in Case 2. Both cases exhibited immunoglobulin heavy chain variable mutations, and heavy-chain variable region gene (VH) 4-39 and VH3-62 were used in Case 1 and Case 2, respectively. In addition, direct Sanger sequencing of exons 4-9 revealed that Case 2 harbored the tumor protein p53 mutation, c.829T>G. Both cases had indications for therapy. Case 1 responded well to chlorambucil treatment, and was still alive at the last follow-up. Conversely, Case 2 exhibited aggressive disease that appeared refractory to treatment, and eventually succumbed to the disease.

Genomic profiling toward precision medicine in non-small cell lung cancer: getting beyond EGFR

Lung cancer remains the leading cause of cancer-related mortality worldwide. The application of next-generation genomic technologies has offered a more comprehensive look at the mutational landscape across the different subtypes of non-small cell lung cancer (NSCLC). A number of recurrent mutations such as TP53, KRAS, and epidermal growth factor receptor (EGFR) have been identified in NSCLC. While targeted therapeutic successes have been demonstrated in the therapeutic targeting of EGFR and ALK, the majority of NSCLC tumors do not harbor these genomic events. This review looks at the current treatment paradigms for lung adenocarcinomas and squamous cell carcinomas, examining genomic aberrations that dictate therapy selection, as well as novel therapeutic strategies for tumors harboring mutations in KRAS, TP53, and LKB1 which, to date, have been considered “undruggable”. A more thorough understanding of the molecular alterations that govern NSCLC tumorigenesis, aided by next-generation sequencing, will lead to targeted therapeutic options expected to dramatically reduce the high mortality rate observed in lung cancer.

RETRACTED: Role of mammalian sirtuin 1 (SIRT1) in lipids metabolism and cell proliferation of goose primary hepatocytes

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors. It has come to the attention of the corresponding author that there are two errors in Section 3.1 of the Results section titled “Effect of overfeeding on gene expression and enzyme activity of several genes in liver”. The first error is that the article contains the wrong number of overfeeding days. The second error is that there are incorrect correlations between liver weight, lipids content in live and plasma metabolic substrates because of the wrong overfeeding days. The authors take responsibility for them and apologize to the readership of Molecular and Cellular Endocrinology.

Gene methylation in gastric cancer

Gastric cancer is one of the most common malignancies and remains the second leading cause of cancer-related death worldwide. Over 70% of new cases and deaths occur in developing countries. In the early years of the molecular biology revolution, cancer research mainly focuses on genetic alterations, including gastric cancer. Epigenetic mechanisms are essential for normal development and maintenance of tissue-specific gene expression patterns in mammals. Disruption of epigenetic processes can lead to altered gene function and malignant cellular transformation. Recent advancements in the rapidly evolving field of cancer epigenetics have shown extensive reprogramming of every component of the epigenetic machinery in cancer, including DNA methylation, histone modifications, nucleosome positioning, noncoding RNAs, and microRNAs. Aberrant DNA methylation in the promoter regions of gene, which leads to inactivation of tumor suppressor and other cancer-related genes in cancer cells, is the most well-defined epigenetic hallmark in gastric cancer. The advantages of gene methylation as a target for detection and diagnosis of cancer in biopsy specimens and non-invasive body fluids such as serum and gastric washes have led to many studies of application in gastric cancer. This review focuses on the most common and important phenomenon of epigenetics, DNA methylation, in gastric cancer and illustrates the impact epigenetics has had on this field.