67-kDa Laminin Receptor in Human Laryngeal Squamous Cell Carcinoma

Expression and significance of laminin receptor in squamous cell carcinoma of the tongue

BACKGROUND

Laminin receptor is a non-integrin cell-surface receptor that binds laminin present on the basement membrane. It has been reported to be associated with infiltration and metastasis of various malignant tumors. However, no studies regarding tongue cancer have been reported. This study aimed to clarify the role of laminin receptor in squamous cell carcinoma of the tongue.

METHODS

We performed immunohistochemical staining of specimens from 66 patients with squamous cell carcinoma of the tongue and assessed laminin receptor expression and clinicopathological factors. As epithelial-mesenchymal transition has been shown to be associated with infiltration and metastasis of malignant tumors, staining for E-cadherin, vimentin, and N-cadherin were also performed.

RESULTS

Of 20 patients with postoperative recurrence, 14 exhibited high laminin receptor expression (p = 0.0025). Kaplan-Meier analysis revealed a significantly shorter time to postoperative recurrence for the high laminin receptor expression group than that for the low laminin receptor expression group (p = 0.0008). Based on multivariate analyses for postoperative recurrence, high laminin receptor expression was associated with poor prognosis (high expression vs. low expression; HR =3.19, 95% CI =0.92-11.08; p = 0.0682). There was a correlation between laminin receptor and N-cadherin (p = 0.0089) but not between laminin receptor and E-cadherin (p = 0.369) or vimentin (p = 0.4221).

CONCLUSION

These results suggest that high laminin receptor expression is a useful prognostic factor for postoperative recurrence and may be a target for molecular therapy to treat squamous cell carcinoma of the tongue.

Potential Therapeutic Significance of Laminin in Head and Neck Squamous Carcinomas

Simple Summary

Head and neck cancers (HNC) account for approximately 500,000 new cases of tumors annually worldwide and are represented by upper aerodigestive tract malignant neoplasms, which particularly arise in oral cavity, larynx, and pharynx tissues. Thus, due to the biological diversity between the upper aerodigestive organs, and to the heterogeneity of risk factors associated with their malignant transformation, HNC behavior, and prognosis seem to strongly vary according to the tumor site. However, despite to the heterogeneity which characterizes head and neck tumors, squamous cell carcinomas (SCC) represent the predominant histopathologic HNC subtype. In this sense, it has been reported that SCC tumor biology is strongly associated with deregulations within the extracellular matrix compartment. Accordingly, it has been shown that laminin plays a remarkable role in the regulation of crucial events associated with head and neck squamous cell carcinomas (HNSCC) progression, which opens the possibility that laminin may represent a convergence point in HNSCC natural history.

Abstract

Head and neck squamous cell carcinomas (HNSCC) are among the most common and lethal tumors worldwide, occurring mostly in oral cavity, pharynx, and larynx tissues. The squamous epithelia homeostasis is supported by the extracellular matrix (ECM), and alterations in this compartment are crucial for cancer development and progression. Laminin is a fundamental component of ECM, where it represents one of the main components of basement membrane (BM), and data supporting its contribution to HNSCC genesis and progression has been vastly explored in oral cavity squamous cell carcinoma. Laminin subtypes 111 (LN-111) and 332 (LN-332) are the main isoforms associated with malignant transformation, contributing to proliferation, adhesion, migration, invasion, and metastasis, due to its involvement in the regulation of several pathways associated with HNSCC carcinogenesis, including the activation of the EGFR/MAPK signaling pathway. Therefore, it draws attention to the possibility that laminin may represent a convergence point in HNSCC natural history, and an attractive potential therapeutic target for these tumors.

A comparative histopathological study of vocal fold polyps in smokers versus non-smokers

BACKGROUND

A large proportion of patients with vocal fold polyps are cigarette smokers. However, prior to this report no comparative study of polyp histopathology in smokers versus non-smokers had been performed.

METHODS

A prospective histopathological study of vocal fold polyps excised from 29 patients was undertaken. This comprised a comparative analysis of polyp histopathology in smokers versus non-smokers and a review of the pertinent literature.

RESULTS

Vocal fold polyps were larger in smokers than in non-smokers. Histopathological features significantly associated with the polyps of smokers versus those of non-smokers were increased keratinisation, dysplasia, a basement membrane thinning and hyaline degeneration.

CONCLUSION

Cigarette smoke has an injurious effect on vocal fold polyp epithelium and leads to increased hyaline degeneration in polyps.

Anti-LRP/LR specific antibody IgG1-iS18 impedes adhesion and invasion of liver cancer cells

Two key events, namely adhesion and invasion, are pivotal to the occurrence of metastasis. Importantly, the 37 kDa/67 kDa laminin receptor (LRP/LR) has been implicated in enhancing these two events thus facilitating cancer progression. In the current study, the role of LRP/LR in the adhesion and invasion of liver cancer (HUH-7) and leukaemia (K562) cells was investigated. Flow cytometry revealed that the HUH-7 cells displayed significantly higher cell surface LRP/LR levels compared to the poorly-invasive breast cancer (MCF-7) control cells, whilst the K562 cells displayed significantly lower cell surface LRP/LR levels in comparison to the MCF-7 control cells. However, Western blotting and densitometric analysis revealed that all three tumorigenic cell lines did not differ significantly with regards to total LRP/LR levels. Furthermore, treatment of liver cancer cells with anti-LRP/LR specific antibody IgG1-iS18 (0.2 mg/ml) significantly reduced the adhesive potential of cells to laminin-1 and the invasive potential of cells through the ECM-like Matrigel, whilst leukaemia cells showed no significant differences in both instances. Additionally, Pearson's correlation coefficients suggested direct proportionality between cell surface LRP/LR levels and the adhesive and invasive potential of liver cancer and leukaemia cells. These findings suggest the potential use of anti-LRP/LR specific antibody IgG1-iS18 as an alternative therapeutic tool for metastatic liver cancer through impediment of the LRP/LR- laminin-1 interaction.

Adhesion and Invasion of Breast and Oesophageal Cancer Cells Are Impeded by Anti-LRP/LR-Specific Antibody IgG1-iS18

Adhesion and invasion have been identified as the two key components of metastasis. The 37 kDa/67 kDa laminin receptor (LRP/LR) is thought to enhance these two processes thus endorsing the progression of cancer. Here we report on LRP/LR and the metastatic potential of MDA-MB 231 breast and WHCO1 oesophageal cancer cells. Western blot analysis revealed a significant increase in total laminin receptor precursor (LRP) levels of breast and oesophageal cancer cells in comparison to non-invasive MCF-7 breast cancer cells, whereas LRP/LR cell surface levels in both cell lines were not significantly different to those of MCF-7 cells as analysed by flow cytometry. Incubation of breast and oesophageal cancer cells with the anti-LRP/LR specific antibody, IgG1-iS18, resulted in significant reduction in the adhesive potential of WHCO1 and MDA-MB 231 cells by 92% and 16%, respectively. Moreover, invasion was significantly impeded by 98% and 25% for WHCO1 and MDA-MB 231 cells, respectively. Pearson's correlation coefficients proved a positive correlation between total LRP/LR levels and invasive potential as well as between the adhesive and invasive potential of breast and oesophageal cancer cells. Our findings suggest that through interference of the LRP/LR-laminin-1 interaction, anti-LRP/LR specific antibody IgG1-iS18 may act as a possible alternative therapeutic tool for metastatic breast and oesophageal cancer treatment.

RNA interference-mediated silencing of laminin receptor 1 (LR1) suppresses migration and invasion and down-regulates matrix metalloproteinase (MMP)-2 and MMP-9 in trophoblast cells: implication in the pathogenesis of preeclampsia

Shallow trophoblast invasion is a common pathological feature of preeclampsia. The 67 kDa laminin receptor 1 (LR1) is a laminin-binding protein that has been reported to be down-regulated in preeclamptic placentas. The aim of the present study was to determine the functional role of LR1 in the migration and invasion of the trophoblast cell line, JEG3 cells. RNA interference mediated by plasmid expressing LR1 short hairpin RNA (shRNA) was utilized to knockdown LR1 expression in JEG3 cells. We found that the mRNA and protein expression levels of LR1 were significantly reduced in LR1-specific shRNA transfected cells compared with the untransfected and control shRNA transfected cells. The wound healing and Transwell invasion assays demonstrated that LR1 knockdown remarkably suppressed the migration and invasion potential of JEG3 cells. The gelatin zymography assay showed that LR1 knockdown greatly reduced matrix metalloproteinase (MMP)-2 and MMP-9 activities in the culture supernatants. Western blot analysis showed that LR1 shRNA significantly decreased expression levels of MMP-2, MMP-9 and phospho-extracellular signal-regulated kinase, but increased expression levels of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 in comparison to the control vector-transfected cells. In conclusion, our data support an important role for LR1 in regulating trophoblast invasion and migration, and suggest a possible pathological mechanism of preeclampsia.

Expression of 67-kDa laminin receptor was associated with tumor progression and poor prognosis in epithelial ovarian cancer

OBJECTIVE

67-kDa laminin receptor (67LR) has been identified as a prognostic biomarker for a variety of human cancers. We investigated the clinical significance of 67LR expression and its functional role in epithelial ovarian cancer (EOC).

METHODS

67LR expression was evaluated by immunohistochemistry in 62 patients with EOC. We assessed the correlation of 67LR expression with clinical characteristics. In vitro experiment was performed for 67LR with inhibition using siRNA to evaluate its role in cell survival, apoptosis, and invasion in EOC cells.

RESULTS

67LR was predominantly expressed on the cell membrane in the majority of EOC samples (45/62, 73%). 67LR expression was significantly correlated with advanced stage (P=0.001). Patients with 67LR expression had shorter progression-free survival among all the patients (P=0.010) and in particular among patients with advanced stages (P=0.046). When 67LR expression was inhibited by siRNA in EOC cells (HeyA8 and A2780), there was a significant decrease of cell proliferation and invasion as well as increase of apoptosis.

CONCLUSION

These findings suggest that 67LR expression may play an important role in tumor progression into advanced stage with poor prognosis in EOC and down-regulation of 67LR on tumor cells may be a therapeutic target in those patients.

Characterization of the ovine ribosomal protein SA gene and its pseudogenes

Background

The ribosomal protein SA (RPSA), previously named 37-kDa laminin receptor precursor/67-kDa laminin receptor (LRP/LR) is a multifunctional protein that plays a role in a number of pathological processes, such as cancer and prion diseases. In all investigated species, RPSA is a member of a multicopy gene family consisting of one full length functional gene and several pseudogenes. Therefore, for studies on RPSA related pathways/pathologies, it is important to characterize the whole family and to address the possible function of the other RPSA family members. The present work aims at deciphering the RPSA family in sheep.

Results

In addition to the full length functional ovine RPSA gene, 11 other members of this multicopy gene family, all processed pseudogenes, were identified. Comparison between the RPSA transcript and these pseudogenes shows a large variety in sequence identities ranging from 99% to 74%. Only one of the 11 pseudogenes, i.e. RPSAP7, shares the same open reading frame (ORF) of 295 amino acids with the RPSA gene, differing in only one amino acid. All members of the RPSA family were annotated by comparative mapping and fluorescence in situ hybridization (FISH) localization. Transcription was investigated in the cerebrum, cerebellum, spleen, muscle, lymph node, duodenum and blood, and transcripts were detected for 6 of the 11 pseudogenes in some of these tissues.

Conclusions

In the present work we have characterized the ovine RPSA family. Our results have revealed the existence of 11 ovine RPSA pseudogenes and provide new data on their structure and sequence. Such information will facilitate molecular studies of the functional RPSA gene taking into account the existence of these pseudogenes in the design of experiments. It remains to be investigated if the transcribed members are functional as regulatory non-coding RNA or as functional proteins.

Proteomic investigation of human burn wounds by 2D-difference gel electrophoresis and mass spectrometry

BACKGROUND

In humans, thermal cutaneous injury represents a serious traumatic event that induces a host of dynamic alterations. Unfortunately the molecular mechanisms that underlie these serious perturbations remain poorly understood. We applied a global analysis method to identify dynamically changing proteins within the burn environment, which could eventually become biomarkers or targets for treatment.

MATERIALS AND METHODS

Protein extracts of normal/unwounded skin and burn wounds were assayed by 2D-difference gel electrophoresis (DIGE), a proteomic technology by which abundance levels of intact proteins (including isoforms) were simultaneously quantified from multiple samples with statistical confidence. Through unsupervised multivariate principal component analysis, protein expression patterns from individual samples were appropriately clustered into their correct temporal healing periods grouped into postburn periods of 1-3 days, 4-6 days, or 7-10 days after injury. Forty-six proteins were subsequently selected for identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

RESULTS

Proteins identified with differential temporal patterns of expression included predictable cytoskeletal proteins such as vimentin, and keratins 1, 5, 6, 16, and 17. Other candidate proteins with potential involvement in healing included heat shock protein 90, members of the serpin family (Serpin B1, SCCA1 and -2), haptoglobin, gelsolin, eIF4A1, IQGAP1, and translationally controlled tumor protein.

CONCLUSIONS

We have used the combined technique, DIGE/mass spectrometry, to capture new insights into cutaneous responses to burn trauma and subsequent processes of early wound healing in humans. This pilot study provides a proteomic snapshot of temporal events that can be used to weave together the interconnected processes that define the response to serious cutaneous injury.

Malignancy-related 67kDa laminin receptor in adenoid cystic carcinoma. Effect on migration and beta-catenin expression

Adenoid cystic carcinoma is a malignant salivary gland neoplasm with recurrence and metastasis. We studied the expression of a malignancy-related non-integrin laminin receptor, the 67LR, in this neoplasm. Immunohistochemistry showed 67LR in adenoid cystic carcinoma. This receptor binds a sequence of laminin beta1 chain, the YIGSR peptide. We studied the effect of 67LR and YIGSR in cells (CAC2) from adenoid cystic carcinoma. Three-dimensional cultures of cells embedded into either laminin-111 gel (controls) or YIGSR-enriched laminin-111 (treated) were prepared and studied by light microscopy. CAC2 cells treated with YIGSR appeared fibroblast-like, while control cells were epithelioid. Blockage of 67LR by antibody abolished YIGSR effect in three-dimensional cultures. We analysed the relevance of 67LR and YIGSR on beta-catenin expression in CAC2 cells. Immunofluorescence and immunoblot showed that YIGSR decreased beta-catenin, while blockage of 67LR restored the presence of this molecule. The 67LR and YIGSR induced fibroblast-like morphology in CAC2 cells, with disruption of cell-cell contacts and decrease of beta-catenin. These features resemble epithelial-mesenchymal transition (EMT). EMT also increases cell migration. In monolayer assays YIGSR increased migration of CAC2 cells. We conclude that 67LR and YIGSR are involved in epithelial-mesenchymal transition, modulation of beta-catenin expression, and migratory activity of CAC2 cells.