Deciphering miRNAs associated with cellular stress response and apoptosis mechanisms regulated by p53 activity in patients with lower lip cancer.

Cancers of the lips and oral cavity are a leading cause of death worldwide. Although they account for only 2% of the global cancer burden, they significantly affect the comfort of patients and eventually lead to a person's death. Also, defects in the cellular stress response and apoptosis mechanisms regulated by p53 activity is an important hallmark of cancer cells. Here, we aimed to decipher miRNAs associated with cellular stress response and apoptosis mechanisms regulated by p53 activity in patient with lower lip cancer and reveal the association of these miRNAs with the clinical course of the disease. The present research included a total of 40 eligible individuals with pathologically confirmed lower lip cancer diagnosis. Formalin-fixed, paraffin-embedded (FFPE) tissue samples of patients were obtained, and miRNAs expressions were analyzed by qPCR. Immunohistochemistry was used to determine p53 and Ki67 expression status. While three of these miRNAs (miR-130a, -375, and -128a) were found to be elevated in tumor cells compared to normal tissues of lower lip cancer patients, five were downregulated (let-7a, -7b, -7c, and miR-138, -23a), but only three were significantly altered. Particularly, we identified three miRNA signatures in which miR-128a was significantly upregulated and miR-23a and let-7c were significantly downregulated in patients with lower lip cancer. Remarkably, let-7c identified to be a promising prognostic factor for lip cancer. Our findings demonstrate that these miRNAs play important regulatory roles in lower lip cancer pathobiology, highlighting their potential relevance in diagnosis and prognosis of these patients. Moreover, these miRNAs can be targeted in future therapeutic interventions against lower lip cancer.

Distinctive expression of DNA replication factors in squamous cell carcinomas of the lip, face and oral cavity.

OBJECTIVE: Uncontrolled proliferation and aberrations in cell-cycle progression are fundamental issues in cancer. In this study we aimed to determine and compare deoxyribonucleic acid (DNA) replication licensing factors at the mRNA and protein levels among squamous cell carcinomas (SCCs) of the lip, facial-skin and oral cavity. MATERIALS AND METHODS: A total of 103 lip, oral and face SCCs were immunohistochemically stained with MCM2 (mini-chromosome maintenance 2), geminin, and ki67, and their labeling-indices were calculated. Also, 57 SCCs from the same regions along with their adjacent normal tissues underwent quantitative reverse transcription-polymerase chain reaction analysis. RESULTS: All three proteins were overexpressed in the studied SCCs, but only geminin (P = 0.004) showed significant difference among the three regions, with higher levels in oral SCCs compared to lip (P = 0.005) and skin (P = 0.024) tumors. Geminin expression did not differ between skin- and lip-SCCs (P = 0.822). MCM2/ki67 ratio was higher in oral- compared to skin-neoplasms (P = 0.039), but no difference was found in geminin/ki67 among the SCC-subsites. There were significant differences in MCM2 and geminin mRNA between carcinomatous- and normal-tissues in all tumors, but not among the three locations. CONCLUSION: MCM2 and geminin are involved in the tumorigenesis of lip, face and oral SCC at both mRNA- and protein-levels. Geminin may have a role in the site-specific biologic behavior of SCC. Skin SCCs had the highest proportion of licensed non-proliferating cells, while actively proliferating cells were more prominent in oral tumors. Regarding DNA replication, lip SCCs seem to be closer to skin tumors compared to their oral counterparts.

EGCG inhibits growth of tumoral lesions on lip and tongue of K-Ras transgenic mice through the Notch pathway.

Epigallocatechin-3-gallate (EGCG), the main active ingredient of green tea, exhibits low toxic side effect and versatile bioactivities, and its anti-cancer effect has been extensively studied. Most of the studies used cancer cell lines and xenograft models. However, whether EGCG can prevent tumor onset after cancer-associated mutations occur is still controversial. In the present study, Krt14-cre/ERT-Kras transgenic mice were developed and the expression of K-RasG12D was induced by tamoxifen. Two weeks after induction, the K-Ras mutant mice developed exophytic tumoral lesions on the lips and tongues, with significant activation of Notch signaling pathway. Administration of EGCG effectively delayed the time of appearance, decreased the size and weight of tumoral lesions, relieved heterotypic hyperplasia of tumoral lesions, and prolonged the life of the mice. The Notch signaling pathway was significantly inhibited by EGCG in the tumoral lesions. Furthermore, EGCG significantly induced cell apoptosis and inhibited the proliferation of tongue cancer cells by blocking the activation of Notch signaling pathway. Taken together, these results indicate EGCG as an effective chemotherapeutic agent for tongue cancer by targeting Notch pathway.

A short review on DNA damage and repair effects in lip cancer.

Increasing trend in oral cancer (0.6% per year) and its related mortality has been reported worldwide since 2010. The United States alone reports an increase of 57% within the past 10 years. This emphasizes the need not only for designing strategies of prevention and planning but also for an effective treatment regime for the various oral cancers. Cancers of the lips, tongue, cheeks, floor of the mouth, and hard palate have been primarily classified under the category of oral cancers. If left undiagnosed, these cancers can be life threatening. Amongst these, the most undesignated and understudied cancer type is the lip carcinoma, which is either categorized under oral cancer or/as well as skin cancer or head and neck cancer. However, lip cancer corresponds to 25-30% of all diagnosed oral cancers. Though the etiology of lip cancer is not yet fully understood, numerous risk factors involved in its development are now being studied. The cells in the lip region are continuously exposed to various DNA damaging agents from endogenous as well as exogenous sources. Flaws in DNA repair mechanisms involved in eliminating these damages may be linked to the origin of carcinogenesis. Accumulation of DNA damage and defect in repair mechanisms may play a role in lip carcinogenesis and progression. This literature review is an exhaustive compilation of the research work performed on the role of DNA damage and repair responses in lip carcinoma which will pave a path for researchers to identify predictive DNA repair biomarker/s for lip cancer, and its diagnosis, prevention, and treatment.

The relevance of miRNAs as promising biomarkers in lip cancer.

OBJECTIVES: This study aimed to analyze the expression of miR-181b, miR-21, miR-31, and miR-345 in actinic cheilitis with and without epithelial dysplasia and lower lip squamous cell carcinomas, and to verify if the deregulated expression of these miRNAs would be indicative of malignant transformation. MATERIALS AND METHODS: The sample was selected from formalin-fixed paraffin-embedded tissues of 19 actinic cheilitis without epithelial dysplasia, 32 actinic cheilitis with epithelial dysplasia, 42 lower lip squamous cell carcinomas, and 10 nonaltered oral mucosa of the lip. The microRNA (miR, miRNA) expression was quantified by real-time RT-PCR and the expression of the selected miRNAs among the groups of actinic cheilitis and lower lip cancer was compared by chi-square. RESULTS: A higher expression of miR-181b, miR-31, and miR-345 was found in actinic cheilitis without epithelial dysplasia in comparison to that in actinic cheilitis with epithelial dysplasia and with lower lip cancer. There were no differences in miR-21 expression between actinic cheilitis and lower lip cancer. Hierarchical clustering analysis showed a tendency for a downregulation of miR-181b, miR-21, miR-31, and miR-345 in most patients with lower lip cancers. CONCLUSIONS: The upregulation of miR-181b, miR-31, and miR-345 expression in actinic cheilitis without epithelial dysplasia and the decrease in the expression of these miRNAs in actinic cheilitis with epithelial dysplasia and in lower lip cancer are potential biomarkers of malignant progression. CLINICAL RELEVANCE: This miRNA signature can help to identify actinic cheilitis with potential to progress to lip cancer.

The prognostic value of CXCR4, α-SMA and WASL in upper lip basal cell carcinomas.

Lip cancers account for 10-12% of the total head and neck cancers and, although squamous cell carcinoma is by far the most common lower lip cancer, the basal cell carcinoma (BCC) seems to be more common for the upper lip. Most BCCs have a clinically indolent behavior, but there are also local aggressive and∕or metastatic cases, with the incidence of such cases being estimated at about 1-10% of all cases of BCC. Many of the molecular mechanisms underlying this aggression are still unknown, which is why our study aimed to investigate the potential prognosis of a few markers, such as C-X-C chemokine receptor type 4 (CXCR4), alpha-smooth muscle actin (α-SMA) and Wiskott-Aldrich syndrome like (WASL) in upper lip BCCs. For this purpose, 24 basocellular cancers with this localization have been investigated immunohistochemically, histopathologically belonging to the next varieties: superficial, nodular, micronodular, adenoid cystic, keratotic, sclerodermiform and mixed. Regardless of the histopathological subtype, for all invasive cases we have recorded an increased reactivity of the three markers especially in the invasion front, reactivity also present at the stroma level, especially at the stroma-parenchyma interface. The most intense immunoreactivity was obtained for the micronodular and sclerodermiform subtypes, confirming their biological behavior to be more aggressive than the rest of the investigated strains. All these results confirm the prognostic value of the CXCR4∕α-SMA∕WASL panel in assessing the biological behavior of the upper lip BCC.

Oral fibropapillomatosis and epidermal hyperplasia of the lip in newborn lambs associated with bovine Deltapapillomavirus.

Congenital fibropapillomatosis of the gingiva and oral mucosa and epidermal hyperplasia of the lip are described, for the first time, in two newborn lambs. Expression of the E5 oncoprotein of bovine deltapapillomavirus types 2 (BPV-2) and -13 (BPV-13) was detected in both fibropapillomas and the hyperplastic epidermal cells suggesting the BPV infection was the cause of the proliferative lesions. No DNA sequences of BPV-1 and BPV-14 were detected. Both BPV-2 and BPV-13 DNA were also amplified from peripheral blood mononuclear cells (PBMCs) of the newborn lambs' dams. The concordance between BPV genotypes detected in the blood of dam and the oral and skin pathological samples of their offspring suggests that a vertical hematogeneous transmission was most likely source of BPV infection. Immunoblotting revealed the presence of E5 dimers allowing the viral protein to be biologically active. E5 dimers bind and activate the platelet derived growth factor ß receptor (PDGFßR), a major molecular mechanism contributing to disease. The detection of E5 protein within the proliferating cells therefore adds further evidence that the BPV infection was the cause of the proliferative lesions seen in these lambs. This is the first evidence of vertical transmission of BPVs in sheep resulting in a clinical disease.

Immunoexpression of glucocorticoid receptor alpha (GRα) isoform and apoptotic proteins (Bcl-2 and Bax) in actinic cheilitis and lower lip squamous cell carcinoma.

BACKGROUND: Actinic cheilitis (AC) is a potentially malignant disorder that can progress to squamous cell carcinoma (SCC), but this process is not fully understood. This study evaluated the immunoexpression of glucocorticoid receptor alpha (GRα) isoform and apoptotic proteins (Bcl-2 and Bax) in AC and lower lip SCC (LLSCC). METHODS: Twenty-two AC and 44 LLSCCs (22 with regional nodal metastasis and 22 without metastasis) were selected. The percentages of nuclear (GRα) and cytoplasmic (GRα, Bcl-2, and Bax) staining in epithelial cells were assessed and correlated with clinical (tumor size/extent and clinical stage) and histopathological parameters (risk of malignant transformation for AC and histopathological grade of malignancy for LLSCCs). RESULTS: Expression of GRα was observed in all cases studied, with relatively high median percentages of positive staining. When compared to AC, LLSCCs exhibited lower nuclear expression and higher cytoplasmic expression of GRα (P < 0.05). Regarding clinicopathological parameters, significant differences were only found for cytoplasmic expression of GRα according to the histopathological grade of LLSCCs (P = 0.036). Higher expression of Bax compared to Bcl-2 was observed in AC and LLSCCs (P < 0.05). In LLSCCs, there was a positive correlation between nuclear and cytoplasmic expressions of GRα (P = 0.006). CONCLUSION: Reduced nuclear translocation and increased cytoplasmic expression of GRα may be important events in lip carcinogenesis but are not involved in the progression of LLSCC. The role of GRα in lip cancer development does not seem to be primarily related to modulations in the expression of Bcl-2 or Bax.

Evaluation of specific modified histones in lip carcinogenesis.

OBJECTIVE: Histones regulate chromatin density and therefore influence gene expression and cellular proliferation. These properties are modified by methylation, acetylation and phosphorylation of histones. The aim of this study was to investigate the variation of specific modified histones in actinic cheilitis (AC) and squamous cell carcinoma of the lip (SCCL). METHODS: Samples of non-neoplastic tissue of the lip (NNTL, n = 9), AC (n = 33), and SCCL (n = 27) were submitted to immunohistochemistry to detect the modified histones H3K36me3, H3K9ac, H4K12ac, and H3S10 ph. RESULTS: Reactivity for all of the modified histones was significantly decreased from NNTL to AC, but not from AC to SCCL. Dysplasia in AC or histological grade in SCCL were not related to the reactivity of any modified histones. CONCLUSIONS: Histone modifications are related to initial actinic damage, but not to malignant transformation in the lip.

Altered Expression of Sphingosine-1-Phosphate Metabolizing Enzymes in Oral Cancer Correlate With Clinicopathological Attributes.

We have determined the gene expression of sphingosine-1-phosphate (S1P) metabolizing enzymes (SphK1, SphK2, SGPL1, SGPP1, SGPP2, PPAP2A, PPAP2B, and PPAP2C) by quantitative real-time polymerase chain reaction in tumor tissues and adjacent normal tissues of 50 oral squamous cell carcinoma (OSCC) patients. Expression of SphK1 and SGPP1 genes was up-regulated significantly in 70% and 75% OSCC tumors respectively. Importantly, expression of SphK2 and PPAP2B was down-regulated in the tumor tissues of 70% OSCC patients. Expression of SphK2 and PPAP2B negatively correlated with tumor-node-metastasis (TNM) staging and tumor volume respectively. Furthermore, LPP1 is an independent predictor of TNM staging and lymph node ratio.

PDGFRa amplification in multiple skin lesions of undifferentiated pleomorphic sarcoma: A clue for intimal sarcoma metastases.

A 62-year-old human immunodeficiency virus-positive man was admitted for multiple cutaneous and subcutaneous nodules on his lower limbs, corresponding to an undifferentiated proliferation of spindle and pleomorphic cells, with irregular nuclei and numerous mitoses. The tumor cells were negative for a large panel of immunohistochemical markers, except CD10. MDM2 immunohistochemical staining was also negative, leading to the diagnosis of Fédération Nationale des Centres de Lutte contre le Cancer grade III undifferentiated pleomorphic sarcoma (UPS). Array-comparative genomic hybridization showed a highly complex karyotype, with amplification of the 4q12 region, an area that contains only the platelet-derived growth factor receptor α (PDGFRa) gene. This amplification of PDFGRa, molecular hallmark of intimal sarcoma (IS), led to the diagnosis of skin IS metastasis. A positron emission tomography showed a hypermetabolic mass protruding in the preaortic area, consistent with the diagnosis of aortic IS. Our study shows that a rare differential diagnosis in peripheral UPS can be IS skin metastasis, and underlines the importance of molecular analyses in UPS.

[Nodular eyelid margin and lip tumors without MEN2b syndrome in a 29 year old man]. / Lidkanten- und Lippentumoren ohne MEN2b-Syndrom bei einem 29-jährigen Mann.

Neuromas of the eyelid margin and lower lip were diagnosed in a 29-year-old man. As the combination of these lesions is indicative of multiple endocrine neoplasia type 2b (MEN2b) syndrome, the presence of a medullary thyroid carcinoma or a pheochromocytoma were excluded by a systematic work-up. A mutation in the RET proto-oncogene was not found by genetic testing. In summary, the patient presented with neuromas on the eyelid margin and lower lip without an association to a syndrome; however, patients with such neuromas should be screened for MEN2b syndrome due to the high mortality.

Lip cancer and pre-cancerous lesions harbor TP53 mutations, exhibit allelic loss at 9p, 9q, and 17p, but no BRAFV600E mutations.

Molecular mechanisms of lip squamous cell carcinoma (LSCC) and actinic cheilitis (AC) are unclear. We aimed at assessing loss of heterozygosity (LOH) and TP53 and BRAF V600E mutations in these lesions. Formalin-fixed paraffin-embedded (FFPE) samples of 17 LSCC and 16 AC were included, with additional 5 fresh LSCC genotyped for TP53 mutations. LOH was assessed by six polymorphic markers located at 9p22, 9q22, and 17p13 and correlated with cell proliferation (Ki-67) and P53 immunostaining. Direct sequencing of TP53 exons 2-11 (fresh samples), and exons 5-9 (FFPE samples) was carried out. BRAF V600E mutation was genotyped in eight LSCC. LOH occurred in at least one marker in 15/17 LSCC and in 9/16 AC. The marker exhibiting the highest frequency of allelic loss (FAL) in LSCC was D9S157 (8/12 informative cases) and D9S287 in AC (4/11 informative cases). Cell proliferation was not correlated with LOH or with the FAL and no correlation between P53 IHC and 17p LOH was observed. We found TP53 missense mutations in both lesions and nonsense in LSCC, including CC>TT transition, which is a marker of UV damage. BRAF V600E mutation was not detected. LOH and TP53 mutations detected in LSCC and AC may be associated with tumorigenesis, whereas BRAF V600E mutation does not seem to significantly contribute to LSCC pathogenesis.

Detection of Rare Variant of SS18-SSX1 Fusion Gene and Mutations of Important Cancer-Related Genes in Synovial Sarcoma of the Lip: Gene Analyses of a Case and Literature Review.

Synovial sarcoma (SS) accounts for 5 to 10% of soft tissue sarcomas; however, intraoral SS is rare. Histopathologically, SS shows a biphasic pattern with epithelial and spindle cell components or a monophasic pattern with only spindle cells. The precise diagnosis of SS, especially at an unusual site, is often a challenge to pathologists and clinical oncologists, because the differential diagnosis of SS includes a broad range of tumors, such as soft tissue sarcomas and carcinomas. In the present case, the patient was a 50-year-old woman who presented with the chief complaint of swelling and a slowly enlarging mass of the lower lip in the mucolabial fold region. The mass was covered with intact mucosa and intraoral examination showed no malignant findings. The clinical diagnosis was a benign tumor and a probable salivary gland tumor. Macroscopically, the excised mass also indicated a benign tumor; however, histopathologic findings suggested the diagnosis of SS. For definitive diagnosis, genetic analyses were performed with conventional polymerase chain reaction and next-generation sequencing. As a result, a rare variant of the SS18-SSX1 fusion transcript, which could not be identified by routine procedures for genetic diagnosis, was detected. In addition, 8 missense mutations of cancer-related genes were confirmed. Detection of the fusion transcript is widely used in the diagnosis of SS; however, reported cases of transcript variants of each fusion gene type are limited. Reports of mutational analysis of cancer-related genes on SS also are rare. The accumulation of rare transcript variants and the cytogenetic characters of SS are suggested to be necessary for assuming a genetic diagnosis of SS.

VEGFR1 and VEGFR2 in lip carcinogenesis and its association with microvessel density.

The aim of the present study was to determine the role of vascular endothelial growth factor receptors (VEGFR1 and VEGFR2) in lip carcinogenesis, to investigate correlations between these markers with microvessel density (MVD) and clinicopathological aspects. Medical records from 27 cases of actinic cheilitis (AC) and 46 cases of lower lip squamous cell carcinoma (LLSCC) were analysed and submitted to immunohistochemistry. VEGFR1- and VEGFR2-immunostained sections were analysed based on percentage of positive epithelial and inflammatory cells, while CD31 was submitted to quantitative analysis to determine MVD. Different patterns of VGFR1 and VEGFR2 expression were observed between AC and LLSCC. VEGFR1 expression in epithelial and inflammatory cells and VEGFR2 expression in epithelial cells were higher in AC compared to LLSCC (p < 0.05). VEGFR1 expression in epithelial cells was higher in LLSCC compared to AC (p < 0.001). Expression of both receptors was not associated to MVD or clinicopathological aspects. A direct correlation was found between epithelial VEGFR1 and VEGFR2 expression (p = 0.02) and between VEGFR2 epithelial and inflammatory expression (p < 0.001). Our findings indicate that activation of VEGFR1 and VEGFR2 in epithelial and inflammatory cells appears to be an early event in lip carcinogenesis.

STAG2 expression in oral cancer and potentially malignant lesions.

Oral cancer is a world health problem, and one of the highest incidence rates of oral cancer worldwide occurs in Brazil. STAG2 is part of the cohesin complex which is responsible for sister chromatid cohesion. STAG2 loss of expression was reported in a range of tumors, and STAG2 loss was found to cause chromosomal instability and aneuploidy in cancer cells. On the basis of these findings, we investigated STAG2 expression in oral cancer and potentially malignant lesions. We investigated STAG2 immunoexpression in oral cancer, lip cancer, oral leukoplakia, and actinic cheilitis, including complete clinical information. Normal oral mucosa samples were included as normal controls. STAG2 protein was highly expressed in all samples. We further tested STAG2 expression in gastric adenocarcinomas and glioblastomas, as these tumor types were previously shown to lose STAG2 expression. We found homogenous expression of STAG2 by these tumor cells. Our results suggest that STAG2 loss of expression is not a common event in oral carcinogenesis.

Metachronous pleomorphic adenomas occurring in the parotid and a minor salivary gland with genetic changes detected by comparative genomic hybridization.

A 32-year-old female underwent an extracapsular dissection for a pleomorphic adenoma (PA) of the parotid gland. Six months later, she presented with an increasing lump on the upper lip that, following excision, was confirmed to be a second PA. Formalin-fixed paraffin embedded tissues were analyzed for chromosomal aberrations. Comparative genomic hybridization analysis showed multiple chromosomal aberrations in the parotid PA. In comparison, no chromosomal aberrations were found in the lip PA. To our knowledge, metachronous benign pleomorphic adenomas occurring in both a major and minor salivary gland is unreported, and furthermore, there are no comparative genomic hybridization reports of this rare occurrence. We discuss the clinicopathological implications.