Fig 7 - uploaded by Jonathon Tinsley
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Histology of sporadic squamous epithelial lesions in bK6-HPV 16e transgenics. (a) Focal hyperplasia/acanthosis in forestomach (male, 261 days). (b) Margin of abnormal 'warty' skin from the upper back. On the left is normal skin, on the right is hyperplastic, hyperkeratotic abnormal skin. (c) Keratin 'pearls' in hair follicles in the tail (female, 382 days). (d) Malignant squamous cell carcinoma in forestomach (male, 253 days); note invasion of lymphatic duct (arrow). Bar markers represent 200 gm (b, c and d) and 100 gm (a).
Source publication
Certain human papillomaviruses (HPVs) have been implicated as important contributory factors in the development of cervical carcinoma and other epithelial malignancies. In order to investigate the role of papillomavirus early gene expression in epithelial oncogenesis in vivo, we produced transgenic mice expressing HPV-16 early region genes from the...
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Context 1
... investigate whether increasing the transgene dosage might lead to further phenotypic effects as a result of increased expression, we produced homozygous bK6- HPV16e transgenic mice in line 135-10. Eyelid opening was generally delayed by several days in homozygous transgenics relative to hemizygotes or non-transgenics. The timing of stomach tumour development appeared similar to that in hemizygotes; however, one small, though clearly malignant, tumour of forestomach epi- thelium has been seen in a mouse presenting with the usual glandular stomach tumour (Fig. 7 d). The incidence of the abnormal ' warty' skin appears to be higher in the homozygous ...
Context 2
... the presence in the tongue and forestomach of considerably higher levels of HPV-16 mRNAs than in the glandular stomach, the forestomachs of the trans- genic mice generally appeared normal and, with one exception noted below, no malignant tumours arising in the squamous epithelium of the forestomach have been detected. Occasional small focal forestomach abnor- malities have been observed in mice presenting with glandular stomach tumours, typically showing localized hyperplasia/acanthosis (Fig. 7 a). No abnormalities have been observed in the tongue. Transgenic mice in line 135- 10 have occasionally developed skin lesions with a grey, warty appearance, either on the upper back where they reach a diameter up to 5 to 10 mm, or on the snout or eyelids. Histologically, these show epithelial hyperplasia, with hyperkeratosis and parakeratosis (Fig. 7b). They appear to be similar to the abnormal skin which developed more widely on the body of other recently described transgenic mice also expressing the HP¥-16 E6/E7 region in skin . However to date malignant progression of these lesions has not been observed, and some have regressed spontaneously after several weeks. Older transgenic mice (approx. 1 year or more) occasionally develop nodules in the tail caused by accumulation of cornified keratinocyte 'pearls' within hair follicles (Fig. 7c); the outer root sheath of hair follicles corresponds to a site of constitutive keratin 6 expression, and hence expected transgene ...
Context 3
... the presence in the tongue and forestomach of considerably higher levels of HPV-16 mRNAs than in the glandular stomach, the forestomachs of the trans- genic mice generally appeared normal and, with one exception noted below, no malignant tumours arising in the squamous epithelium of the forestomach have been detected. Occasional small focal forestomach abnor- malities have been observed in mice presenting with glandular stomach tumours, typically showing localized hyperplasia/acanthosis (Fig. 7 a). No abnormalities have been observed in the tongue. Transgenic mice in line 135- 10 have occasionally developed skin lesions with a grey, warty appearance, either on the upper back where they reach a diameter up to 5 to 10 mm, or on the snout or eyelids. Histologically, these show epithelial hyperplasia, with hyperkeratosis and parakeratosis (Fig. 7b). They appear to be similar to the abnormal skin which developed more widely on the body of other recently described transgenic mice also expressing the HP¥-16 E6/E7 region in skin . However to date malignant progression of these lesions has not been observed, and some have regressed spontaneously after several weeks. Older transgenic mice (approx. 1 year or more) occasionally develop nodules in the tail caused by accumulation of cornified keratinocyte 'pearls' within hair follicles (Fig. 7c); the outer root sheath of hair follicles corresponds to a site of constitutive keratin 6 expression, and hence expected transgene ...
Context 4
... the presence in the tongue and forestomach of considerably higher levels of HPV-16 mRNAs than in the glandular stomach, the forestomachs of the trans- genic mice generally appeared normal and, with one exception noted below, no malignant tumours arising in the squamous epithelium of the forestomach have been detected. Occasional small focal forestomach abnor- malities have been observed in mice presenting with glandular stomach tumours, typically showing localized hyperplasia/acanthosis (Fig. 7 a). No abnormalities have been observed in the tongue. Transgenic mice in line 135- 10 have occasionally developed skin lesions with a grey, warty appearance, either on the upper back where they reach a diameter up to 5 to 10 mm, or on the snout or eyelids. Histologically, these show epithelial hyperplasia, with hyperkeratosis and parakeratosis (Fig. 7b). They appear to be similar to the abnormal skin which developed more widely on the body of other recently described transgenic mice also expressing the HP¥-16 E6/E7 region in skin . However to date malignant progression of these lesions has not been observed, and some have regressed spontaneously after several weeks. Older transgenic mice (approx. 1 year or more) occasionally develop nodules in the tail caused by accumulation of cornified keratinocyte 'pearls' within hair follicles (Fig. 7c); the outer root sheath of hair follicles corresponds to a site of constitutive keratin 6 expression, and hence expected transgene ...
Citations
... High-risk human papillomavirus (HR-HPV) was recently found in anorectal NEC without mutations in TP53 or RB1, suggesting HR-HPV infection as an alternative mechanism of E2F deregulation in NEC [141]. In line with such a mechanism, gastric NEC with full penetrance arise in mice with expression of HPV-16 early region under the control of the bovine keratin 6 promoter [142]. ...
Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) are a rare, heterogeneous group of tumors that originate from the endocrine system of the gastrointestinal tract and pancreas. GEP-NEN are subdivided according to their differentiation into well differentiated gastroenteropancreatic neuroendocrine tumors (NET) and poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (NEC). Since GEP-NEN represent rare diseases only limited data from large prospective, randomized clinical trials are available, and recommendations for treatment of GEP-NEN are in part based on data from retrospective analyses or case series. In this context, tractable disease models that reflect the situation in humans and allow to recapitulate the different clinical aspects and diseases stages of GEP-NET or GEP-NEC are urgently needed. In this review, we highlight available data on mouse models for gastroenteropancreatic neuroendocrine neoplasia. We discuss how these models reflect tumor biology of human disease and whether these models could serve as a tool for understanding the pathogenesis of GEP-NEN, for disease modeling and pharmacosensitivity assays facilitating prediction of treatment response in patients. In addition, open issues applicable for future developments will be discussed.
... Li, Karam, and Gordon 1995;Syder et al. 2004). One utilizes human papilloma virus (HPV)-16 (Searle et al. 1994) that is not associated with gastric cancer in humans (Kamangar et al. 2006). A fourth utilized adenovirus 12 (Koike et al. 1989) and a fifth utilized a constitutively active dioxin/aryl hydrocarbon receptor (Andersson et al. 2002), ...
Gastric cancer is the fifth most common cancer and the third leading cause of cancer death worldwide. The majority of patients with gastric cancer are diagnosed with disseminated disease and even patients diagnosed with early stage disease have high rates of recurrence. The utility of current mouse models of gastric cancer is limited by slow development of gastric tumors and lack of metastasis. Here I describe a new mouse model of gastric cancer driven by p53 loss, Cdh1 loss, and oncogenic Kras expression in gastric parietal cells (referred to as ACKPY mice). I generated these mice to investigate the contribution of oncogenic Kras to the progression of gastric cancer given the high rate of mutation and amplification of the RTK/Ras pathway identified in gastric cancer patients. These mice develop mixed-type gastric adenocarcinomas with metastases to lymph nodes, lung, and liver. Oncogenic Kras and loss of Trp53 is sufficient to drive rapid carcinogenesis in a variety of models. Therefore, I tested if loss of E-cadherin was necessary for the onset of gastric adenocarcinoma in gastric parietal cells by generating ACKPY mice with one or two alleles of wild-type Cdh1 (E-cadherin). E-cadherin expression significantly increased survival and the limited number of mice with gastric tumors have tumors that were focal in nature, suggesting an additional event was necessary for gastric tumorigenesis. Loss of E-cadherin expression was observed in some of these tumors, suggesting that its loss may be necessary for gastric tumorigenesis in this model. I show that loss of E-cadherin in our model increases β-catenin signaling and that inhibition of β-catenin signaling prolonged survival of ACKPY mice. Microarray data comparing gene expression in stomachs harvested from Cdh1fl/fl and Cdh1fl/+ mice showed a correlation between E-cadherin loss and upregulation of oncogenic Kras signaling. Gene sets regulated by each of the main Kras effector pathways were overrepresented in our microarray data. Examination of ERK phosphorylation revealed that E-cadherin likely does not regulate MAPK activity in our model. The upregulation of oncogenic Kras target genes that result from the loss of E-cadherin may alternatively be explained by E-cadherin regulation of other Kras effector pathways.
... Murine models of chronic Helicobacter infection are definitive and reproducible models that can be used to investigate the molecular mechanism of gastric carcinogenesis. However, there are limitations to Helicobacter mouse models, including the limited number of H. pylori strains available, the slow time course for the progression of tumors, the low incidence rate of advanced gastric cancer, and the anatomical differences between humans and mice (Table 1).17,18,19,20,28,31,46,66,67,68,69,70,71 ...
Gastric cancer is one of the most common cancers in the world. Animal models have been used to elucidate the details of the molecular mechanisms of various cancers. However, most inbred strains of mice have resistance to gastric carcinogenesis. Helicobacter infection and carcinogen treatment have been used to establish mouse models that exhibit phenotypes similar to those of human gastric cancer. A large number of transgenic and knockout mouse models of gastric cancer have been developed using genetic engineering. A combination of carcinogens and gene manipulation has been applied to facilitate development of advanced gastric cancer; however, it is rare for mouse models of gastric cancer to show aggressive, metastatic phenotypes required for preclinical studies. Here, we review current mouse models of gastric carcinogenesis and provide our perspectives on future developments in this field.
... Other early models included transgenic mice carrying the human adenovirus type 12 (Ad12) early region 1 under control of the mouse mammary tumor virus (MMTV) long terminal repeat (LTR), which developed adenocarcinoma or adenosquamous carcinoma [26]. In addition, transgenic mice expressing HPV-16 early region of the bovine keratin 6 gene promoter developed glandular stomach tumors [27]. However, these models did not progress to cancer through the atrophy-metaplasia-dysplasia sequence, as described by Correa [28], nor were they associated with Helicobacter infection or chronic inflammation. ...
Animal models have greatly enriched our understanding of the molecular mechanisms of numerous types of cancers. Gastric cancer is one of the most common cancers worldwide, with a poor prognosis and high incidence of drug-resistance. However, most inbred strains of mice have proven resistant to gastric carcinogenesis. To establish useful models which mimic human gastric cancer phenotypes, investigators have utilized animals infected with Helicobacter species and treated with carcinogens. In addition, by exploiting genetic engineering, a variety of transgenic and knockout mouse models of gastric cancer have emerged, such as INS-GAS mice and TFF1 knockout mice. Investigators have used the combination of carcinogens and gene alteration to accelerate gastric cancer development, but rarely do mouse models show an aggressive and metastatic gastric cancer phenotype that could be relevant to preclinical studies, which may require more specific targeting of gastric progenitor cells. Here, we review current gastric carcinogenesis mouse models and provide our future perspectives on this field.
... Interestingly, in contrast to Tax-or HBxtransformed cells, E6-, E7-, or E6/E7-transformed cells rarely produce tumors when transplanted into nude mice [Kaur and McDougall, 1988;Pirisi et al., 1988;Woodworth et al., 1988]. However, numerous versions of E6, E7, and E6/E7 transgenic mice develop either benign tumors or cancers [Kondoh et al., 1991;Arbeit et al., 1993Arbeit et al., , 1994Griep et al., 1993;Lambert et al., 1993;Searle et al., 1994;Comerford et al., 1995;Herber et al., 1996;Song et al., 1999]. The frequency and type of malignancy seems to depend largely on the promoter used to drive expression of the viral oncogene(s). ...
It is estimated that 15% of all cancers are etiologically linked to viral infection. Specific cancers including adult T-cell leukemia, hepatocellular carcinoma, and uterine cervical cancer are associated with infection by human T-cell leukemia virus type I, hepatitis B virus, and high-risk human papilloma virus, respectively. In these cancers, genomic instability, a hallmark of multistep cancers, has been explicitly linked to the expression of oncoproteins encoded by these viruses. This review discusses mechanisms utilized by these viral oncoproteins, Tax, HBx, and E6/E7, to mediate genomic instability and cellular transformation.
... Low doses of MNNG administered to mongolian gerbils (Meriones unguiculatus) infested with Helicobacter pylori caused tumours in the glandular stomach (6). Stomach tumours were also detected in transgenic mice expressing viral oncogenes such as the SV40 large T antigen (7), adenovirus 12 E1A/E1B (8) and the papilloma virus 16 early region (9). ...
... Therefore, the study of the time factor was focused on males. The animals were sacrificed at 3,5,9,10,12,13,16,27,37 and 52 weeks for males and 3, 9, 10, 16, 27, 38 and 52 weeks for females. The stomachs were removed and rinsed in cold saline solution. ...
The dioxin/Aryl hydrocarbon (Ah) receptor is a ligand-activated transcription factor known to mediate the toxic effects of the environmental pollutants dioxins.
Transgenic mice expressing a constitutively active Ah receptor were found to develop gastric tumours.
Segments of the normal gastric glands of the corpus region (lined by foveolar, parietal and cardio-pyloral cells) developed cystic tumours. Tumours in the submucosa and muscularis propria consisted of large cysts surrounded by organized lymphocytic, connective, squamous and adipose tissues and vessels. Those tumours were obviously hamartomatous in nature. Despite the fact that the tumours had an inward growth and penetrated all stomach layers, no metastases developed.
The model here described may open new vistas into the investigation of the role of environmental pollutants in the development of gastric hamartomas.
... The genomes of certain types of human papillomavirus (HPV) such as HPV types 16 and 18, which are also called high-risk HPVs, are frequently found in carcinoma and precancerous lesions of the uterine cervix, suggesting causative relationship between infection and carcinogenesis (zur Hausen, 1989). Recently, numbers of transgenic mice carrying HPV16 E6/E7 gene has been established, however, these HPV16 E6/E7 transgenic mice did not exhibit any tissue specificity for the induction of tumorigenesis (Arbeit et al., 1993;Greenhalgh et al., 1994;Sasagawa et al., 1994;Searle et al., 1994). ...
... These findings suggest that HPV16 E6/E7 expression can induce aberrant epithelial hyperplasia and epidermal differentiation within the suprabasal compartment of epidermis. These findings were similar to that of other transgenic mouse models (Searle et al., 1994). ...
Human papillomavirus type 16 (HPV16) has been known as a major causative factor for the development of uterine cervical carcinomas. To investigate the in vivo activity of HPV16 expressed in squamous epithelia, transgenic mice harboring HPV16 E6/E7 with human keratin 14 (hK14) promoter were generated. Grossly, hK14 driven HPV16 E6/E7 transgenic mice exhibited multiple phenotypes, including wrinkled skin that was apparent prior to the appearance of hair in neonates, thickened ears, and loss of hair in adults. Transgenic mice with phenotype exhibiting severe wrinkled skin and a lack of hair growth died at the age of 3-4 weeks. Histological analysis revealed that in transgenic mice survived beyond the initial 3-4 weeks, HPV16 E6/E7 causes epidermal hyperplasia in multiple transgenic lineages with high incidence of transgene penetration. This epithelial hyperplasia was characterized by an expansion of the proliferating compartment and keratinocytes, and was associated with hyperkeratosis. Such activities were significantly higher in the skin of transgenic mice than that of the normal mice. Thus, these transgenic mice appeared to be useful for the expression of HPV16 E6/E7 gene and subsequent analysis on hyperkeratosis.
... No data were available at other times in embryonic development. In humans, keratin IV presents in all layers of the epidermis at 10 weeks and becoming totally absent at around 20 weeks (Peter et al., 1994;Seth et al., 1998). On the basis of keratin IV absent at around 20 weeks, Keratin IV transfectant cell line (HaCaT, human origin cell line) may be identified to reduce a degree of Keratin IV expression day by day. ...
Keratins, the constituents of epithelial intermediate filaments, are precisely regulated in a tissue and development specific manner. There are two types of keratin in bovine. The type I is acidic keratin and the type II is neutral/basic keratin. 1.5 kb of 5' flanking sequence of Korean cattle Keratin IV gene, type II keratin (59 kDa), was cloned and sequenced. A symmetrical motif AApuCCAAA are located in a defined region upstream of the TATA box. Proximal SP1, AP1, E-box and CACC elements as the major determinants of transcription are identified. When it was compared to the bovine sequence from -600 bp to ATG upstream, the homology was 97% in nucleotide sequence. Several A and T sequences, located in the promoter region, are deleted in the Korean cattle. An expression vector consisted of Korean cattle Keratin IV gene promoter/SV40 large T antigen was transfected to HaCaT cell (Epithelial keratinocyte). The transformed HaCaT cells showed active proliferation when treated with PDGF (Platelet-derived growth factor) in 0.3% soft agar compared to control cells. These results indicate that Korean cattle Keratin IVgene promoter can be used as a promoter for transfection into epithelial cell.
... On the other hand, TCDD has been reported to induce expression of the cyclincyclindependent kinase inhibitor p27 (Kip1) in certain cells (29). Interestingly, mice develop adenocarcinomas in the glandular stomach after expression of viral oncoproteins binding the retinoblastoma protein Rb (30,31). Notably, the AhR has been reported recently to interact physically with Rb (32, 33) via an as-yet-unresolved mechanism. ...
The dioxin/aryl hydrocarbon receptor (AhR) functions as a ligand-activated transcription factor regulating transcription of a battery of genes encoding xenobiotic metabolizing enzymes. Known receptor ligands are environmental pollutants including polycyclic aromatic hydrocarbons and polychlorinated dioxins. Loss-of-function (gene-disruption) studies in mice have demonstrated that the AhR is involved in toxic effects of dioxins but have not yielded unequivocal results concerning the physiological function of the receptor. Gain-of-function studies therefore were performed to unravel the biological functions of the AhR. A constitutively active AhR expressed in transgenic mice reduced the life span of the mice and induced tumors in the glandular part of the stomach, demonstrating the oncogenic potential of the AhR and implicating the receptor in regulation of cell proliferation.
... Comparison with other animal models for HPV-16-associated carcinogenesis. Several laboratories have previously achieved expression of papillomavirus genes in the epidermis (2,16,31,46). In those studies, the transgenic mice carried either the complete early region of HPV-16 (2, 46) or both E6 and E7 (16,31). ...
The human papillomavirus type 16 (HPV-16) genome is commonly present in human cervical carcinoma, in which a subset of the viral genes, E6 and E7, are expressed. The HPV-16 E6 and E7 gene products can associated with and inactivate the tumor suppressor proteins p53 and Rb (the retinoblastoma susceptibility gene product), and in tissue culture cells, these viral genes display oncogenic properties. These findings have led to the hypothesis that E6 and E7 contribute to cervical carcinogenesis. This hypothesis has recently been tested by using transgenic mice as an animal model. HPV-16 E6 and E7 together were found to induce cancers in multiple tissues in which they were expressed, including squamous cell carcinoma, the cancer type most commonly associated with HPV-16 in the human cervix. We have extended these studies to investigate the in vivo activities of HPV-16 E7 when expressed in squamous epithelia of transgenic mice. Grossly, E7 transgenic mice had multiple phenotypes, including wrinkled skin that was apparent prior to the appearance of hair on neonates, thickened ears, and loss of hair in adults. In lines of mice expressing higher levels of E7, we observed stunted growth and mortality at an early age, potentially caused by an incapacity to feed. Histological analysis demonstrated that E7 causes epidermal hyperplasia in multiple transgenic lineages with high penetrance. This epithelial hyperplasia was characterized by an expansion of the proliferating compartment and an expansion of the keratin 10-positive layer of cells and was associated with hyperkeratosis. Hyperplasia was found at multiple sites in the animals in addition to the skin, including the mouth palate, esophagus, forestomach, and exocervix. In multiple transgenic lineages, adult animals developed skin tumors late in life with low penetrance. These tumors arose from the squamous epithelia and from sebaceous glands and were characterized histologically to be highly differentiated, locally invasive, and aggressive in their growth properties. On the basis of these phenotypes, we conclude that HPV-16 E7 can alter epithelial cell growth parameters sufficiently to potentiate tumorigenesis in mice.
