Low-dose retinoic acid enhances in vitro invasiveness of human oral squamous-cell-carcinoma cell lines

ALDH1A3 promotes invasion and metastasis in triple-negative breast cancer by regulating the plasminogen activation pathway

Aldehyde dehydrogenase 1A3 (ALDH1A3) is a cancer stem cell marker that promotes metastasis. Triple-negative breast cancer (TNBC) progression has been linked to ALDH1A3-induced gene expression changes. To investigate the mechanism of ALDH1A3-mediated breast cancer metastasis, we assessed the effect of ALDH1A3 on the expression of proteases and the regulators of proteases that degrade the extracellular matrix, a process that is essential for invasion and metastasis. This revealed that ALDH1A3 regulates the plasminogen activation pathway; it increased the levels and activity of tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA). This resulted in a corresponding increase in the activity of serine protease plasmin, the enzymatic product of tPA and uPA. The ALDH1A3 product all-trans-retinoic acid similarly increased tPA and plasmin activity. The increased invasion of TNBC cells by ALDH1A3 was plasminogen-dependent. In patient tumours, ALDH1A3 and tPA are co-expressed and their combined expression correlated with the TNBC subtype, high tumour grade and recurrent metastatic disease. Knockdown of tPA in TNBC cells inhibited plasmin generation and lymph node metastasis. These results identify the ALDH1A3-tPA-plasmin axis as a key contributor to breast cancer progression.

Effectiveness of cetuximab as preemptive postsurgical therapy for oral squamous cell carcinoma patients with major risk: a single-center retrospective cohort study

A retrospective cohort study was performed to investigate the effectiveness of preemptive postsurgical therapy with cetuximab for patients with a major risk of recurrence or metastasis after clinical complete resection of primary oral squamous cell carcinoma (OSCC). The study period was from 2007 to 2019 for patients treated at the Department of Oral and Maxillofacial Surgery, Dokkyo Medical University School of Medicine. OSCC patients with major risk (n = 88) in the follow-up period were divided into groups with no postsurgical treatment (NP group), with standard postsurgical treatment (SP group), and with postsurgical treatment including cetuximab (CP group), and prognosis were compared among those groups. The 5-year overall survival rate was significantly higher in patients who received postsurgical treatment with cetuximab (CP) compared to that in the other two groups ((CP vs. NP, p = 0.028; CP vs. SP, p = 0.042). Furthermore, we performed multivariate analysis to evaluate the effects of the main components of the treatment. Among CDDP, radiotherapy, and cetuximab, only cetuximab significantly contributed to improved survival by univariate analysis (crude HR:0.228, 95%CI:0.05-0.968, p = 0.045). cetuximab also showed the same tendency in multivariate analysis, although p value did not reach significant level (Adjusted HR: 0.233, 95%CI: 0.053-1.028, p = 0.054). The results suggest that the postsurgical treatment with cetuximab as a preemptive postsurgical therapy after complete surgical resection of a visible tumor is considerably effective for OSCC patients with major risk, in other words, invisible dormant metastasis.

Expression of Potential Dermal Progenitor Cell Markers in the Tumour and Stroma of Skin Adnexal Malignant and Benign Tumours

Stem cells are multipotent cells that maintain the skin epidermis including skin appendages such as hair follicle, sebaceous glands, and sweat glands. There is evidence that reciprocal signalling between the epidermis and the dermis plays an important role in skin development, homeostasis, wound repair, and skin cancer. The origin of skin cancer that derive from skin appendages is still controversial, including basal cell carcinoma and even more of rare tumours such as sebaceous carcinomas and whether those tumours originate from resident tissue stem cells. To investigate whether markers reported to label dermal progenitor cells are preserved in the tumour including the tumour stroma of skin adnexal tumours, we tested 45 human basal cell carcinomas, including superficial, nodular, adenoid, infiltrating, and sclerosing types, and further 38 human tumours of skin appendages including 13 sebaceous adenomas and carcinomas, 20 eccrine sweat gland tumours, and 5 pilomatricomas, syringomas, and hair follicle tumours for the expression of the potential dermal and epidermal cell markers CRABP1, Nestin, and Ephrin B2 and compared these findings with healthy, age-related human epidermis. We detected that CRABP1, Nestin, and Ephrin B2 are expressed in the intratumoural stroma as well as the tumour invasive front of skin tumours of appendages and BCCs.

High FABP5 Versus CRABPII Expression Ratio in Recurrent Craniopharyngiomas: Implications for Future Treatment

BACKGROUND AND OBJECTIVE

Recurrence is a major problem in craniopharyngioma (CP) management. Recent study shows that high FABP5/CRABPII may be related to tumor growth and that all-trans retinoic acid (ATRA) may suppress primary CP growth. We studied the expression profile of FABP5 and CRABPII in recurrent CP tissue and the effect of ATRA on recurrent CP cells.

METHODS

Fifty cases of patients with CP were enrolled in the retrospective study. Among them, 15 were recurrent. Fresh specimens were collected for immunohistochemistry, reverse transcription polymerase chain reaction, and western blotting analysis of FABP5 and CRABPII. Fresh specimens from 6 primary and recurrent CPs were collected and subjected to cell culture using an explants method. ATRA at various concentrations was applied to recurrent CP cell culture, and cell growth was recorded and analyzed.

RESULTS

Immunohistochemistry, reverse transcription polymerase chain reaction, and western blot study showed that FABP5 was expressed significantly higher in recurrent tumors, whereas CRABPII was expressed significantly higher in primary tumors. The FABP5/CRABPII ratio was significantly higher in recurrent rather than primary tumors. Recurrent CP cells grew faster than primary cells, and ATRA induced cellular apoptosis and inhibited CP cell growth in a dose-dependent manner.

CONCLUSIONS

A high expression ratio between FABP5 and CRABPII may be related to CP tumor recurrence and ATRA could be a potential therapeutic agent for CP chemotherapy.

Tissue inhibitor of metalloproteinases in oral squamous cell carcinomas - a therapeutic target?

Matrix metalloproteinases (MMPs) are proteases responsible for remodeling the extracellular matrix (ECM) and enabling spreading and metastasis of tumor cells, a common phenomenon in oral squamous cell carcinomas (OSCC). They are strongly blocked by several inhibitors, among which we must highlight, for their specificity and potency, the endogenous tissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4). The goal of this paper is to describe the expression of TIMPs in OSCC, determining their relation with clinical, histological and prognostic factors, delving into OSCC regulation mechanisms and discussing the use of exogenous TIMPs to treat this type of tumors. Expression of TIMPs in OSCC is higher in tumors than in normal tissue, which correlates with an increase of metastatic risk and regional lymph node affectation. Although some metalloproteinases inhibitors (MMIs) have shown promising results in the treatment of these tumors, their use in OSCC has not been widely tested; and although some indirect MMIs, like COX-2 inhibitors, flavonoids and endostatin seem to have beneficial effects on the invasive capacity of OSCC through regulation of MMPs and TIMP levels, routine clinical use has not been accepted yet.

Genome-wide transcriptional profiling analysis of all trans retinoic acid-treated tongue carcinoma SCC-9 cells

BACKGROUND

All trans retinoic acid (ATRA) is used as standard of care in promyelocytic leukemia. Not much is known about the gene expression profile in ATRA-treated tongue cancer cells. We performed a genome-wide transcriptional profiling of ATRA-treated tongue cancer cells to understand the pathways that mediate ATRA action in tongue cancer.

METHODS

We measured the effects of ATRA on the proliferation of SCC-9 human tongue carcinoma cells. The differential gene expression profile was measured by microarray analysis of untreated and ATRA-treated cells and expression of key genes was validated by real-time RT-PCR.

RESULTS

ATRA treatment (24 and 48 hr) significantly inhibited SCC-9 cell proliferation in a dose-dependent manner. SCC-9 cells treated for 48 hr with ATRA showed upregulation of 276 genes, including ANGPTL4, GDF15, ICAM1 and TUSC4, and downregulation of 43 genes, including CXCL10. Validation by real-time PCR showed a significant upregulation of intracellular adhesion molecule 1 (ICAM1) and downregulation of CXCL10 and IL32.

CONCLUSIONS

ATRA had an anti-tumor effect in tongue cancer cells. This effect is likely mediated via upregulation of ICAM1 and downregulation of CXCL10 and IL32.

Enhancement of ATRA-induced differentiation of neuroblastoma cells with LOX/COX inhibitors: an expression profiling study

BACKGROUND

We performed expression profiling of two neuroblastoma cell lines, SK-N-BE(2) and SH-SY5Y, after combined treatment with all-trans retinoic acid (ATRA) and inhibitors of lipoxygenases (LOX) and cyclooxygenases (COX). This study is a continuation of our previous work confirming the possibility of enhancing ATRA-induced cell differentiation in these cell lines by the application of LOX/COX inhibitors and brings more detailed information concerning the mechanisms of the enhancement of ATRA-induced differentiation of neuroblastoma cells.

METHODS

Caffeic acid, as an inhibitor of 5-lipoxygenase, and celecoxib, as an inhibitor on cyclooxygenase-2, were used in this study. Expression profiling was performed using Human Cancer Oligo GEArray membranes that cover 440 cancer-related genes.

RESULTS

Cluster analyses of the changes in gene expression showed the concentration-dependent increase in genes known to be involved in the process of retinoid-induced neuronal differentiation, especially in cytoskeleton remodeling. These changes were detected in both cell lines, and they were independent of the type of specific inhibitors, suggesting a common mechanism of ATRA-induced differentiation enhancement. Furthermore, we also found overexpression of some genes in the same cell line (SK-N-BE(2) or SH-SY5Y) after combined treatment with both ATRA and CA, or ATRA and CX. Finally, we also detected that gene expression was changed after treatment with the same inhibitor (CA or CX) in combination with ATRA in both cell lines.

CONCLUSIONS

Obtained results confirmed our initial hypothesis of the common mechanism of enhancement in ATRA-induced cell differentiation via inhibition of arachidonic acid metabolic pathway.

Vitamin A metabolism is impaired in human ovarian cancer

OBJECTIVES

We have previously reported that loss in expression of a protein considered critical for vitamin A homeostasis, cellular retinol-binding protein 1 (CRBP1), is an early event in ovarian carcinogenesis. The aim of the present study was to determine if loss of vitamin A metabolism also occurs early in ovarian oncogenesis.

METHODS

We assessed CRBP1 expression by immunohistochemistry in ovaries prophylactically removed from women with a genetic risk for ovarian cancer. Furthermore, we investigated the ability of normal, immortalized but nontumorigenic, and tumorigenic human ovarian epithelial cells to synthesize retinoic acid and retinaldehyde when challenged with a physiological dose of retinol, and determined expression levels of the retinoid-related genes, RARalpha, RXRalpha, CRABP1, CRABP2, RALDH1 and RALDH2 in these cells.

RESULTS

Immunohistochemistry revealed loss of CRBP1 expression in potentially preneoplastic lesions in prophylactic oophorectomies. HPLC analysis of vitamin A metabolism showed production of retinoic acid in four independent, normal human ovarian surface epithelial (HOSE) cell cultures upon exposure to retinol. However, only one of two SV40-immortalized HOSE cell lines made RA, while none of the ovarian carcinoma cell lines produced detectable RA due to complete loss of RALDH2.

CONCLUSIONS

The impaired conversion of retinol to RA in ovarian cancer cells and decreased CRBP1 protein expression in prophylactic oophorectomies support our hypothesis that concomitant losses of vitamin A metabolism and CRBP1 expression contribute to ovarian oncogenesis.

Rap1GAP promotes invasion via induction of matrix metalloproteinase 9 secretion, which is associated with poor survival in low N-stage squamous cell carcinoma

The objective of the current study was to investigate the effects of Rap1GAP on invasion and progression of head and neck squamous cell carcinoma (SCC) and the role of matrix metalloproteinase (MMP) 9 and MMP2 in this process. Rap1GAP functions by switching off Rap1, the Ras-like protein that has been associated with carcinogenesis. Previous findings suggest that Rap1GAP acts as a tumor suppressor protein in SCC by delaying the G(1)-S transition of the cell cycle. However, cells transfected with Rap1GAP exhibit a more invasive phenotype than corresponding vector-transfected control cells. MMP2 and MMP9 are enzymes that mediate SCC invasion via degradation of the extracellular matrix. Using SCC cells transfected with empty vector or Rap1GAP, cell invasion and MMP secretion were determined by Matrigel assays and gelatin zymography, respectively. Rap1GAP up-regulated transcription and secretion of MMP2 and MMP9, as assayed by quantitative reverse transcription-PCR and zymography. Furthermore, chemical and RNA interference blockade of MMP2/MMP9 inhibited invasion by Rap1GAP-transfected cells. Immunohistochemical staining of a human oropharyngeal SCC tissue microarray showed that Rap1GAP and MMP9 expression and staining intensity are correlated (P < 0.0001) and that, in early N-stage lesions of SCC, high MMP9 is prognostic of poor disease-specific survival (P < 0.05). Furthermore, Rap1GAP staining is correlated with MMP2 (P < 0.03). MMP2 in combination with N stage has a prognostic effect on time to indication of surgery at primary site. MMP2 intensity is also positively correlated with T stage (P < 0.015). In conclusion, Rap1GAP inhibits tumor growth but induces MMP2- and MMP9-mediated SCC invasion and tumor progression, suggesting a role for this protein as a biomarker for early N-stage, aggressive SCCs.

Characterization of 3 oral squamous cell carcinoma cell lines with different invasion and/or metastatic potentials

PURPOSE

Proteolytic enzymes may confer specific types of invasion and metastasis in patients with oral squamous cell carcinoma (OSCC). The purpose of this study was to determine if OSCC that invades adjacent bone has different proteolytic enzyme expression profiles than OSCC that metastasizes to lymph nodes or distant organs. Three OSCC cell lines, BHY, HSC-3, and HN, with known behavior regarding bone invasion and lymph node and distant metastatic profiles, were evaluated. The characteristics of a control, human normal nasal epithelial cell line (HNEC), and BHY, HSC-3 and HN were evaluated with regard to their expression of the matrix metalloproteinases and cathepsins.

MATERIALS AND METHODS

Expressions of proteolytic enzymes including matrix metalloproteinase, MMP-1, MMP-2, MMP-3, MMP-9, extracellular matrix metalloproteinase inducer (EMMPRIN), cathepsin B, and cathepsin L were compared using immunocytochemistry and flow cytometry in 3 OSCC cell lines and HNEC. The cell morphologies of these 4 cell lines were compared using transmission electron microscopy (TEM).

RESULTS

All OSCC cell lines showed higher expression of all the proteolytic proteins when compared with HNEC, except the HSC-3 cell line showed no difference in the expression of MMP-9. There was no detectable difference at the expression level of MMP-1, MMP-2, MMP-3, cathepsin B, and cathepsin L in any of the OSCC cell lines. However, MMP-9 and EMMPRIN levels were higher in the BHY cell line. According to electron microscopy, the cells of the HSC-3 cell line were the smallest and least differentiated among the 3 OSCC cell lines. The BHY cell line was the most highly differentiated showing interdigitation and numerous cell junctions.

CONCLUSIONS

MMPs play an important role in the invasion and metastasis of oral cancer. MMP-9 might play a more important role than MMP-2 during invasion. Increased expression of MMP-1, MMP-9, and EMMPRIN proteins might be involved in invasion of OSCC to adjacent bone, as they are necessary for the collagen matrix degradation. Increased expression of MMP-3, cathepsin B and L in OSCC might be associated with both invasion and a high incidence of metastasis.

Expression of the Epidermal Growth Factor Seven-Transmembrane Member CD97 Correlates with Grading and Staging in Human Oral Squamous Cell Carcinomas

Introduction: The oral squamous cell carcinoma (OSCC) is the sixth most common malignant tumor worldwide. No significant better progress has been made in the treatment of OSCCs during the last decades. The heterodimeric CD97 protein is a epidermal growth factor seven-transmembrane family member and was identified as a dedifferentiation marker in thyroid carcinomas. Nothing is known about CD97 in OSCCs.

Material and Methods: Employing UV-laser microdissection, CD97 and its ligand CD55 were investigated in normal oral mucosa and OSCCs (n = 78) by multiplex reverse transcription-PCR. Frozen sections were investigated by immunohistochemistry. The effects of retinoic acid and sodium butyrate on the CD97/CD55 expression in OSCC cell lines were determined by quantitative PCR, immunocytochemistry, and flow cytometry.

Results: Weak CD97 transcripts were expressed in normal mucosa and normal basal epithelial cells revealed specific CD97 immunostaining. Strong CD97 transcripts were detected in pT3/T4 and G3/G4 OSCC tissues, whereas pT1/T2 and G1/G2 carcinomas revealed weak CD97 transcript levels. A weak CD97 immunostaining was observed in pT1/T2 and G1/G2 tumors. By contrast, intensive CD97 immunostaining was detected in pT3/T4 OSCCs and G3/G4 lesions. CD55 gene expression was low in normal mucosa. All OSCCs, irrespective of stage and grading, displayed strong CD55 immunostaining. Sodium butyrate and retinoic acid inhibited CD97 mRNA and protein in OSCC cell lines. Interestingly, CD55 was up-regulated by both substances.

Conclusion: We identified CD97 as a novel marker of dedifferentiated OSCC. Interaction of CD97 and CD55 may facilitate adhesion of OSCC cells to surrounding surfaces that would result in metastases and bad prognosis.