Limits...
HOXA1 is overexpressed in oral squamous cell carcinomas and its expression is correlated with poor prognosis.

Bitu CC, Destro MF, Carrera M, da Silva SD, Graner E, Kowalski LP, Soares FA, Coletta RD - BMC Cancer (2012)

Bottom Line: In particular, HOXA1, which has been described as one of the HOX members that plays an important role in tumorigenesis, was significantly more expressed in OSCCs compared to healthy oral mucosas.Further analysis demonstrated that overexpression of HOXA1 in HaCAT human epithelial cells promotes proliferation, whereas downregulation of HOXA1 in human OSCC cells (SCC9 cells) decreases it.A high number of HOXA1-positive cells was significantly associated with T stage, N stage, tumor differentiation and proliferative potential of the tumors, and was predictive of poor survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, CP 52, CEP 13414-018 Piracicaba, São Paulo, Brazil. coletta@fop.unicamp.br

ABSTRACT

Background: HOX genes encode homeodomain-containing transcription factors involved in the regulation of cellular proliferation and differentiation during embryogenesis. However, members of this family demonstrated oncogenic properties in some malignancies. The present study investigated whether genes of the HOXA cluster play a role in oral cancer.

Methods: In order to identify differentially expressed HOXA genes, duplex RT-PCR in oral samples from healthy mucosa and squamous cell carcinoma was used. The effects of HOXA1 on proliferation, apoptosis, adhesion, invasion, epithelial-mesenchymal transition (EMT) and anchorage-independent growth were assessed in cells with up- and down-regulation of HOXA1. Immunohistochemical analysis using a tissue microarray (TMA) containing 127 oral squamous cell carcinomas (OSCC) was performed to determine the prognostic role of HOXA1 expression.

Results: We showed that transcripts of HOXA genes are more abundant in OSCC than in healthy oral mucosa. In particular, HOXA1, which has been described as one of the HOX members that plays an important role in tumorigenesis, was significantly more expressed in OSCCs compared to healthy oral mucosas. Further analysis demonstrated that overexpression of HOXA1 in HaCAT human epithelial cells promotes proliferation, whereas downregulation of HOXA1 in human OSCC cells (SCC9 cells) decreases it. Enforced HOXA1 expression in HaCAT cells was not capable of modulating other events related to tumorigenesis, including apoptosis, adhesion, invasion, EMT and anchorage-independent growth. A high number of HOXA1-positive cells was significantly associated with T stage, N stage, tumor differentiation and proliferative potential of the tumors, and was predictive of poor survival. In multivariate analysis, HOXA1 was an independent prognostic factor for OSCC patients (HR: 2.68; 95% CI: 1.59-2.97; p = 0.026).

Conclusion: Our findings indicate that HOXA1 may contribute to oral carcinogenesis by increasing tumor cell proliferation, and suggest that HOXA1 expression might be helpful as a prognostic marker for patients with OSCC.

Show MeSH

Related in: MedlinePlus

Diagram of expression of the members of HOXA locus in samples from healthy oral mucosa, normal-looking oral mucosa adjacent to OSCC, and OSCC. Each symbol represents one specific sample, and their positions are preserved throughout the image. Circles represent healthy oral mucosa derived from patients without contact with the main oral cancer risk factors, and triangles and squares represent normal-looking mucosa and OSCC from the same patient, respectively. Open symbols indicate silent (inactive) HOXA genes, whereas closed symbols indicate active genes. Note the abundance of active genes in OSCC samples.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3351375&req=5

Figure 1: Diagram of expression of the members of HOXA locus in samples from healthy oral mucosa, normal-looking oral mucosa adjacent to OSCC, and OSCC. Each symbol represents one specific sample, and their positions are preserved throughout the image. Circles represent healthy oral mucosa derived from patients without contact with the main oral cancer risk factors, and triangles and squares represent normal-looking mucosa and OSCC from the same patient, respectively. Open symbols indicate silent (inactive) HOXA genes, whereas closed symbols indicate active genes. Note the abundance of active genes in OSCC samples.

Mentions: In order to determine the expression of the genes in the HOXA locus, total RNA was extracted from tissue samples and RT-PCR was performed using specific oligonucleotides designed against each of the genes in the HOXA locus and GAPDH. Figure 1 depicts the diagram of HOXA gene expression in the healthy oral mucosa, normal-looking oral mucosa near OSCC and OSCC samples. Two out of 11 genes (HOXA6 and HOXA9) were silenced in all samples of this study. The majority of the healthy oral mucosa samples from patients not exposed to recognized OSCC risk factors did not express HOXA genes, with the exception of HOXA1, HOXA2 and HOXA4, which were expressed by 30% of the samples. The expression in normal-looking oral mucosa near OSCC samples was more abundant when compared to the expression observed in OSCC samples. However, considering the intensity levels of gene expression, as represented by the densitometric ratio of the optical density of target transcript/GAPDH bands, we identified that the expression of HOXA4, HOXA5, HOXA7 and HOXA10 was significantly higher in OSCC samples compared to both healthy oral mucosa and normal-looking mucosa near OSCC. The expressions of HOXA1, HOXA2 and HOXA13 were significantly higher in OSCC samples when compared to healthy oral mucosa. Of particular interest, the expression of HOXA1 was also found to be significantly higher in normal-looking oral mucosa near OSCC than in healthy oral mucosa (Figure 2). Since HOXA1 expression was associated with tumors from different organs, and its dysregulated expression can influence numerous cellular processes related to tumorigenesis and was correlated with poor prognosis, we further analyzed the role of HOXA1 in OSCC.


HOXA1 is overexpressed in oral squamous cell carcinomas and its expression is correlated with poor prognosis.

Bitu CC, Destro MF, Carrera M, da Silva SD, Graner E, Kowalski LP, Soares FA, Coletta RD - BMC Cancer (2012)

Diagram of expression of the members of HOXA locus in samples from healthy oral mucosa, normal-looking oral mucosa adjacent to OSCC, and OSCC. Each symbol represents one specific sample, and their positions are preserved throughout the image. Circles represent healthy oral mucosa derived from patients without contact with the main oral cancer risk factors, and triangles and squares represent normal-looking mucosa and OSCC from the same patient, respectively. Open symbols indicate silent (inactive) HOXA genes, whereas closed symbols indicate active genes. Note the abundance of active genes in OSCC samples.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3351375&req=5

Figure 1: Diagram of expression of the members of HOXA locus in samples from healthy oral mucosa, normal-looking oral mucosa adjacent to OSCC, and OSCC. Each symbol represents one specific sample, and their positions are preserved throughout the image. Circles represent healthy oral mucosa derived from patients without contact with the main oral cancer risk factors, and triangles and squares represent normal-looking mucosa and OSCC from the same patient, respectively. Open symbols indicate silent (inactive) HOXA genes, whereas closed symbols indicate active genes. Note the abundance of active genes in OSCC samples.
Mentions: In order to determine the expression of the genes in the HOXA locus, total RNA was extracted from tissue samples and RT-PCR was performed using specific oligonucleotides designed against each of the genes in the HOXA locus and GAPDH. Figure 1 depicts the diagram of HOXA gene expression in the healthy oral mucosa, normal-looking oral mucosa near OSCC and OSCC samples. Two out of 11 genes (HOXA6 and HOXA9) were silenced in all samples of this study. The majority of the healthy oral mucosa samples from patients not exposed to recognized OSCC risk factors did not express HOXA genes, with the exception of HOXA1, HOXA2 and HOXA4, which were expressed by 30% of the samples. The expression in normal-looking oral mucosa near OSCC samples was more abundant when compared to the expression observed in OSCC samples. However, considering the intensity levels of gene expression, as represented by the densitometric ratio of the optical density of target transcript/GAPDH bands, we identified that the expression of HOXA4, HOXA5, HOXA7 and HOXA10 was significantly higher in OSCC samples compared to both healthy oral mucosa and normal-looking mucosa near OSCC. The expressions of HOXA1, HOXA2 and HOXA13 were significantly higher in OSCC samples when compared to healthy oral mucosa. Of particular interest, the expression of HOXA1 was also found to be significantly higher in normal-looking oral mucosa near OSCC than in healthy oral mucosa (Figure 2). Since HOXA1 expression was associated with tumors from different organs, and its dysregulated expression can influence numerous cellular processes related to tumorigenesis and was correlated with poor prognosis, we further analyzed the role of HOXA1 in OSCC.

Bottom Line: In particular, HOXA1, which has been described as one of the HOX members that plays an important role in tumorigenesis, was significantly more expressed in OSCCs compared to healthy oral mucosas.Further analysis demonstrated that overexpression of HOXA1 in HaCAT human epithelial cells promotes proliferation, whereas downregulation of HOXA1 in human OSCC cells (SCC9 cells) decreases it.A high number of HOXA1-positive cells was significantly associated with T stage, N stage, tumor differentiation and proliferative potential of the tumors, and was predictive of poor survival.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Oral Diagnosis, School of Dentistry, State University of Campinas, CP 52, CEP 13414-018 Piracicaba, São Paulo, Brazil. coletta@fop.unicamp.br

ABSTRACT

Background: HOX genes encode homeodomain-containing transcription factors involved in the regulation of cellular proliferation and differentiation during embryogenesis. However, members of this family demonstrated oncogenic properties in some malignancies. The present study investigated whether genes of the HOXA cluster play a role in oral cancer.

Methods: In order to identify differentially expressed HOXA genes, duplex RT-PCR in oral samples from healthy mucosa and squamous cell carcinoma was used. The effects of HOXA1 on proliferation, apoptosis, adhesion, invasion, epithelial-mesenchymal transition (EMT) and anchorage-independent growth were assessed in cells with up- and down-regulation of HOXA1. Immunohistochemical analysis using a tissue microarray (TMA) containing 127 oral squamous cell carcinomas (OSCC) was performed to determine the prognostic role of HOXA1 expression.

Results: We showed that transcripts of HOXA genes are more abundant in OSCC than in healthy oral mucosa. In particular, HOXA1, which has been described as one of the HOX members that plays an important role in tumorigenesis, was significantly more expressed in OSCCs compared to healthy oral mucosas. Further analysis demonstrated that overexpression of HOXA1 in HaCAT human epithelial cells promotes proliferation, whereas downregulation of HOXA1 in human OSCC cells (SCC9 cells) decreases it. Enforced HOXA1 expression in HaCAT cells was not capable of modulating other events related to tumorigenesis, including apoptosis, adhesion, invasion, EMT and anchorage-independent growth. A high number of HOXA1-positive cells was significantly associated with T stage, N stage, tumor differentiation and proliferative potential of the tumors, and was predictive of poor survival. In multivariate analysis, HOXA1 was an independent prognostic factor for OSCC patients (HR: 2.68; 95% CI: 1.59-2.97; p = 0.026).

Conclusion: Our findings indicate that HOXA1 may contribute to oral carcinogenesis by increasing tumor cell proliferation, and suggest that HOXA1 expression might be helpful as a prognostic marker for patients with OSCC.

Show MeSH
Related in: MedlinePlus