Video-microscopic imaging of cell spatio-temporal dispersion and migration

Live-cell imaging has become a powerful analytical tool in most cell biology laboratories. The scope of this paper is to give an overview of the environmental considerations for maintaining living cells on the microscope stage and the technical advances permitting multi-parameter imaging. The paper will then focus on two-dimensional and three-dimensional analysis of cell dispersion and migration and finally give a brief insight on computational modeling of the cell behavior.

Aneuploidy, but not Ki-67 or EGFR expression, is associated with recurrences in basal cell carcinoma

BACKGROUND

Basal cell carcinoma (BCC), the most common skin cancer, has an overall excellent prognosis, but recurrences are frequent. The value of classical clinical and histological prognostic factors to predict recurrences remain limited.

METHODS

In order to evaluate the prognostic value of Epidermal Growth Factor Receptor (EGFR) expression, Ki-67 antigen expression and DNA ploidy, we compared primary tumors in 20 patients who had subsequent local recurrences and 20 matched controls without recurrences. DNA ploidy was determined by image cytometry, and EGFR and Ki-67 expression were studied by immunohistochemistry.

RESULTS

Statistical analysis of the intensity and the percentage of EGFR expression and Ki-67 antigen expression did not show any significant difference between the two groups. In contrast, we found that 78% of primary BCC in patients who experienced recurrences vs. 32% in the control group were aneuploid (p = 0.005).

CONCLUSIONS

Aneuploidy is a risk factor for recurrences. This factor should be useful in clinical practice and require evaluation in further studies.

Human papillomavirus 16 E6, L1, L2 and E2 gene variants in cervical lesion progression

The human papillomavirus (HPV) 16 E6 genome variant 350G has been found to be more prevalent in women with persistent infection and cervical disease progression than the HPV16 E6 prototype 350T. In this study, we examined whether women who progressed to a high-grade lesion, yet were infected with the prototype 350T, showed variants in other HPV genes such as L1, L2 and E2. Although we detected variants within these genes, they could not explain this phenomenon. Indeed they correlated similarly with variant 350G and prototype 350T. These data indicate that polymorphisms in HPV16 E6 rather than in the other analyzed genes play a role in determining the risk for cervical lesion progression and that additional factors are likely to be required as well.

[Cell ploidy: predictive factor of locally advanced prostate cancer]

OBJECTIVE

This study was designed to demonstrate that the study of cell ploidy on biopsies of clinically localized prostate cancers can contribute to the diagnosis of a tumour extending beyond the prostatic capsule and can complete imaging for local staging.

METHODS

Analysis of the histological results of 140 patients operated for clinically localized prostate cancer distinguished two groups of patients in whom the initial tumour was Gleason score 6 or 7. The first group was composed of 33 patients whose tumour was classified as pT3 and the second group was composed of 24 patients whose tumour was classified as pT2. The cell ploidy study was performed on biopsies and operative specimens in the two groups.

RESULTS

In the pT3N0M0 group, 72% of tumours presented an aneuploid contingent versus 16% of tumours of the pT2N0M0 group. A strong correlation was demonstrated between cell ploidy and tumour stage (p = 0.0002) and a highly significant correlation was observed between tumour stage and the presence of a tumour contingent with ploidy greater than 5C (p = 0.0009).

CONCLUSION

The presence of an aneuploid contingent on biopsies of clinically localized prostate cancer significantly increases the risk of a more advanced tumour. This technique could therefore constitute a simple complementary tool in the staging of prostate cancer in combination with transrectal MRI, but this needs to be confirmed by other studies.

Beta-catenin and ZO-1: shuttle molecules involved in tumor invasion-associated epithelial-mesenchymal transition processes

The cytoplasmic/nuclear relocalization of beta-catenin and ZO-1 from the adherens and tight junctions are common processes of the epithelial-mesenchymal transition (EMT) associated with tumor invasion. Data are now accumulating to demonstrate that these molecules, which shuttle between the plasma membrane and the nucleus or the cytosol, are involved in signaling pathways, and contribute to the regulation of genes such as vimentin or matrix metalloproteinase-14 which are turned on during EMT.

Human airway surface epithelial regeneration is delayed and abnormal in cystic fibrosis

Cystic fibrosis (CF) at an advanced stage of the disease is characterized by airway epithelial injury and remodelling. Whether CF remodelling is related to infection and inflammation or due to an abnormal regenerative process is still undecided. We have recently established the expression and secretion profiles of interleukin (IL)-8, matrix metalloproteinase (MMP)-7, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1 during non-CF airway epithelial regeneration in a humanized nude mouse xenograft model. To enhance our understanding of CF remodelling, we compared the regeneration process of non-infected human CF and non-CF nasal epithelia. In both CF and non-CF situations, epithelial regeneration was characterized by successive steps of cell adhesion and migration, proliferation, pseudostratification, and terminal differentiation. However, histological examination of the grafts showed a delay in differentiation of the CF airway epithelium. Cell proliferation was higher in the regenerating CF epithelium, and the differentiated CF epithelium exhibited a pronounced height increase and basal cell hyperplasia in comparison with non-CF epithelium. In addition, while the number of goblet cells expressing MUC5AC was similar in CF and non-CF regenerated epithelia, the number of MUC5B-immunopositive goblet cells was lower in CF grafts. The expression of human IL-8, MMP-7, MMP-9, and TIMP-1 was enhanced in CF epithelium, especially early in the regenerative process. Together, our data strongly suggest that the regeneration of human CF airway surface epithelium is characterized by remodelling, delayed differentiation, and altered pro-inflammatory and MMP responses.

Quantitative videomicroscopic analysis of the sociologic behavior of non-invasive and invasive tumor cell lines

To analyze the spatial distribution of tumor cell lines with different invasive properties, we used time-lapse videomicroscopic recordings associated with software programs we have developed for quantification. We observed that non-invasive tumor cells rapidly formed small clusters which aggregated to form larger clusters, whereas highly invasive tumor cells remained isolated and did not form clusters. An attraction index computed from a cellular automaton model was used to quantify the degree of attraction-repulsion between cells. The results suggest that the cluster formation by noninvasive cells is not related to a global attraction model and that the random (dispersed) distribution of invasive cells is not related to cell repulsion. According to these results, we can conclude that random cell movement combined with the intrinsic properties of cells explains the phenomenon of cluster formation.

[Multiple recurrent papillomas of the breast: case report]

We report the case of a patient presenting multiple recurrent papillomas of the breast. This mild mammary pathology, developed at the expense of the galactophoric ducts, recurred four times, in a nodular way, in spite of in sano surgical resection. The retrospective study of the cell proliferation and the DNA quantification of the cells constitutive of the papillomas, on several samples, underlined evolutive lesions, which could be predictive of a malignant degeneration. This observation allows us to discuss the management of this rare mild mammary pathology, which can sometimes lead to invasive breast carcinoma.

HPV prevalence, viral load and physical state of HPV-16 in cervical smears of patients with different grades of CIN

Human papillomavirus (HPV) infection is the most important event in malignant transformation of human cervical epithelium. We analysed in cervical smears, HPV genotypes with a focus on single/multiple infections, then characteristics of HPV-16 infections (presence of other genotypes, viral load and physical state) according to the grade of histological lesions. The purpose of this study was to know if these parameters could allow to differentiate histological diagnoses. DNA was extracted from 363 cervical samples corresponding to 24 cases without lesion, 96 CIN1, 92 CIN2, 144 CIN3 and 7 cancers. Our results show that HPV-16 was predominant and its prevalence increased with the severity of lesions (CIN1: 27.1%; CIN3: 65.3%). In addition, we showed that the frequency of single infections, as compared with multiple infections, increased with the severity of the lesion (CIN1: 25.0%; CIN3: 54.8%). Among HPV-16 positive samples (n = 170), we found that viral load, determined on cervical samples by real-time PCR, did not vary significantly according to the different CIN grades. Concerning HPV-16 integration, the mixed and integrated HPV-16 forms, already present in women with normal histology, increased to the benefit of pure episomal forms with the severity of lesions (normal cervix: 28.6%; CIN3: 73.8%). Thus, our data raise the question of the viral load as a valuable clinical parameter to discriminate between lesion grades. Moreover, we emphasize integration as an early event in cervical carcinogenesis, increasing with the severity of lesions. Finally, this study underlines the importance of single versus multiple infections linked to the severity of CIN.

E-cadherin regulates human Nanos1, which interacts with p120ctn and induces tumor cell migration and invasion

Down-regulation of the epithelial cell-cell adhesion molecule E-cadherin is frequently associated with tumor formation and progression. Besides its role in physical cell-cell adhesion, E-cadherin is also thought to be involved in intracellular signaling in normal epithelial cells. In these cells, the Armadillo catenin p120ctn binds to the cytoplasmic domain of E-cadherin and stabilizes the adhesion complexes. On loss of E-cadherin, cytoplasmic p120ctn might accumulate and contribute to tumor malignancy. We used suppression subtractive hybridization to search for genes regulated by E-cadherin expression. We isolated human Nanos1 as a transcript of which levels decrease on E-cadherin reexpression in a human breast cancer cell line. The hNanos1 protein bears a COOH-terminal (CCHC)(2) zinc finger domain and belongs to an evolutionarily conserved protein family sharing functions in germ cell development in both vertebrates and invertebrates. We found an inverse correlation between E-cadherin and hNanos1 expression in various cell lines and under diverse conditions. Conditional expression of hNanos1 in human colorectal DLD1 cancer cells functionally abolished cell-cell adhesion. It induced cytoplasmic translocation of p120ctn, as well as strong migratory and invasive properties. We also found that the NH(2)-terminal domain of hNanos1, which is conserved only among mammals, interacts with p120ctn. hNanos1 counteracted the stimulatory effect of p120ctn on cell protrusion formation. Together, these findings describe a new function for hNanos1 as a downstream effector of E-cadherin loss contributing to tumor progression. Targeting hNanos1 might be a promising strategy in the treatment of E-cadherin-negative tumors in particular.

[The epidemiology of genital human papillomavirus infections]

Human papillomavirus (HPV) genital infections are the most frequent sexually transmitted infections. Their prevalence varies considerably with age and geographic area. The incidence of these infections is particularly high at the onset of the sexual activity. High-risk HPV type 16 is the most prevalent type, and in general, high-risk HPV are more frequent than low-risk HPV. The majority of genital HPV infections is asymptomatic, but can induce lesions in the genital tract: genital warts due to low-risk HPV; high-grade lesions due to high-risk HPV; cancers with a more or less important fraction, depending on the localization, due to high-risk HPV. In particular, high-risk HPV are responsible for almost all cervical carcinomas.

Increased risk for cervical disease progression of French women infected with the human papillomavirus type 16 E6-350G variant

To test the significance of human papillomavirus (HPV) type 16 and HPV16 E6 variants as risk factors for viral persistence and progression to high-grade lesion, we did a nested case-control study within a cohort study of >15,000 Caucasian French women. Three groups infected with high-risk HPV were compared: (a) women with cleared infection (controls, n = 201), (b) women with persistent infection (cases, n = 87), and (c) women who progressed into high-grade lesion (cases, n = 58). Women with persistent HPV infection and those that progressed into high-grade lesions were likelier to harbor HPV16 than other high-risk HPV types [odds ratio (OR), 2.4; 95% confidence interval (95% CI), 1.3-4.3 and OR, 4.2; 95% CI, 2.2-8.1, respectively]. Notably, especially elevated ORs of persistence (3.0; 95% CI, 1.4-6.7) and progression (6.2; 95% CI, 2.7-14.3) were found among women who harbored the HPV16 350G variant. Thus, HPV type and HPV16 variant seem to be risk factors for viral persistence and progression of infections into high-grade cervical lesions.

P16 is overexpressed in cutaneous carcinomas located on sun-exposed areas

BACKGROUND

Recently, an increased expression of P16, a cell cycle regulatory tumor suppressor protein, has been demonstrated in cervical squamous neoplasms as a marker of malignancy. In contrast, studies performed in skin carcinomas led to contradictory results.

OBJECTIVES

Our first aim was to evaluate P16 expression in different types of non-melanoma skin cancers compared with normal skin and benign tumors. The second aim was to evaluate the relationship between P16 expression and the location of skin tumors (i.e. exposed versus non exposed sites). Finally, we also studied Ki67 expression in skin carcinomas and control biopsies.

METHODS

Skin biopsy specimens with typical histologic features of squamous cell carcinoma (SCC; n = 30), Bowen's disease (BD; n = 17), basal cell carcinoma (BCC; n = 10), seborrheic keratosis (SK; n = 10) and normal human skin (NHS; n = 9) were obtained from 76 patients seen at our institution between 2001 and 2003. In all cases, P16 and Ki67 expression were evaluated by immunohistochemistry and image analysis.

RESULTS

P16 overexpression was observed in 58% of cutaneous carcinomas (SCC: 60%; BD: 58%; BCC: 50%) versus 0% of SK or NHS (0%) (p = 0.006). Ki67 expression in over 5% of tumour cells was observed in 69% of cutaneous carcinomas (SCC: 54%; BD: 76%; BCC: 80%) versus 16% in the group including SK (30%) and NHS (0%) (p = 0.04). Overexpression of P16 was associated with a high rate of Ki67 positive tumour cells in 23/57 malignant skin tumors (40%). Both P16 was associated and Ki-67 were negative in 7/57 cases (12%). Sixty-eight percent of tumors located on sun-exposed areas versus 23% of those located on non sun-exposed areas overexpressed P16 (p = 0.02).

CONCLUSION

Our study demonstrated that the expression of P16 and Ki67 is associated with skin carcinomas. No difference was observed according to histological types of carcinomas, suggesting that P16 and Ki67 expression did not correlate with the degree of proliferation and malignancy. Within cutaneous carcinoma specimens, P16 overexpression was significantly associated with the location on sun-exposed areas, suggesting a possible induction of P16 overexpression by UV radiation.

Endometrial tumor invasiveness is related to metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 expressions

Matrix metalloproteinase (MMPs) expression has been linked to gynecological tumor aggressiveness. The objective of this study was to determine MMP-2, MMP-7, and MMP-9 and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 expression in endometrial malignancies and their relation to clinical and histologic parameters. Formalin-fixed, paraffin-embedded tumor samples from 50 patients with endometrial carcinoma treated between 1999 and 2004 were stained with specific monoclonal antibodies. The tumors were grouped according to the FIGO classification. The staining results were compared to histologic and clinical data. Semiquantitative analysis of MMP and TIMP expression showed a significant difference in TIMP-2 expression according to the histologic subtype (P = 0.03) and also a trend towards a difference in MMP-9 expression (P = 0.05). MMP-2 expression increased and TIMP-2 expression fell as the histologic grade increased (P = 0.0007, P < 0.0001, respectively). MMP-2 expression correlated with lymph node metastasis (P = 0.04), while TIMP-2 expression correlated with the depth of myometrial invasion (P = 0.01), vasculolymphatic space involvement (P = 0.02), and lymph node metastasis (P = 0.0003). These results support the involvement of MMPs and TIMPs in endometrial tumor growth and progression. High MMP-2 and low TIMP-2 expression were the most potent markers of endometrial tumors with a high risk of local and distant spread.

Overview of the European and North American studies on HPV testing in primary cervical cancer screening

Several studies suggest that HPV testing is more sensitive than cytology in primary cervical screening. These studies had different designs and were reported in different ways. Individual patient data were collected for all European and North American studies in which cytology was routinely performed and HPV testing was included as an additional parallel test. More than 60,000 women were included. The sensitivity and specificity of HPV testing were compared with routine cytology, both overall and for ages <35, 35-49 and 50+. The age-specific prevalence of high risk HPV (hr-HPV) was also analysed. HPV testing was substantially more sensitive in detecting CIN2+ than cytology (96.1% vs. 53.0%) but less specific (90.7% vs. 96.3%). The sensitivity of HPV testing was similar in all studies carried out in different areas of Europe and North America, whereas the sensitivity of cytology was highly variable. HPV sensitivity was uniformly high at all ages, whereas the sensitivity of cytology was substantially better in women over the age of 50 than in younger women (79.3% vs. 59.6%). The specificity of both tests increased with age. Positivity rates for HPV testing in women without high-grade CIN were region dependent. These results support the use of HPV testing as the sole primary screening test, with cytology reserved for women who test HPV positive. Large demonstration projects are needed to fully evaluate this strategy.

Expression of a disintegrin and metalloprotease (ADAM and ADAMTS) enzymes in human non-small-cell lung carcinomas (NSCLC)

A Disintegrin and Metalloprotease (ADAM) are transmembrane proteases displaying multiple functions. ADAM with ThromboSpondin-like motifs (ADAMTS) are secreted proteases characterised by thrombospondin (TS) motifs in their C-terminal domain. The aim of this work was to evaluate the expression pattern of ADAMs and ADAMTS in non small cell lung carcinomas (NSCLC) and to investigate the possible correlation between their expression and cancer progression. Reverse transcriptase–polymerase chain reaction (RT–PCR), Western blot and immunohistochemical analyses were performed on NSCLC samples and corresponding nondiseased tissue fragments. Among the ADAMs evaluated (ADAM-8, -9, -10, -12, -15, -17, ADAMTS-1, TS-2 and TS-12), a modulation of ADAM-12 and ADAMTS-1 mRNA expression was observed. Amounts of ADAM-12 mRNA transcripts were increased in tumour tissues as compared to the corresponding controls. In sharp contrast, ADAMTS-1 mRNA levels were significantly lower in tumour tissues when compared to corresponding nondiseased lung. These results were corroborated at the protein level by Western blot and immunohistochemistry. A positive correlation was observed between the mRNA levels of ADAM-12 and those of two vascular endothelial growth factor (VEGF)-A isoforms (VEGF-A₁₆₅ and VEGF-A₁₂₁). Taken together, these results providing evidence for an overexpression of ADAM-12 and a lower expression of ADAMTS-1 in non-small-cell lung cancer suggest that these proteases play different functions in cancer progression.