Mesenchymal stromal cells derived from cervical cancer tumors induce TGF-ß1 expression and IL-10 expression and secretion in the cervical cancer cells, resulting in protection from cytotoxic T cell activity.

Cervical cancer (CeCa) tumors are characterized by increased expression of TGF-ß1 and IL-10, which are correlated with downregulated expression of major histocompatibility complex class I antigens (HLA-I) on cancer cells and a reduced immune response mediated by cytotoxic T lymphocytes (CTLs). Mesenchymal stromal cells (MSCs) are important components in the tumor microenvironment that have been suggested to contribute to cancer progression through the induction of TGF-ß1 and IL-10. In this study, we provided evidence that MSCs derived from cervical tumors (CeCa-MSCs) cocultured with CeCa cells induced significant expression of TGF-ß1 and secretion of IL-10 by CeCa cells compared to MSCs derived from the normal cervix (NCx-MSCs) and normal bone marrow (BM-MSCs; gold standard). This increase in expression was associated with a significant downregulation of HLA-I molecules and protection of the cells against specific CTL lysis. Interestingly, the addition of the neutralizing antibody anti-TGF-ß to the CeCa/CeCa-MSCs coculture strongly inhibited the expression and production of IL-10 by CeCa cells. Anti-TGF-ß as well as anti-IL-10 also abolished HLA-I downregulation, and reversed the inhibition of CTL cytotoxicity. These results provide evidence that TGF-ß1 and IL-10 could play an important role in the downregulation of HLA-I molecules on CeCa cells induced by tumor MSCs. Our findings suggest a novel mechanism through which MSCs may protect tumor cells from immune recognition by specific CTLs.

Increased expression of HOXB2 and HOXB13 proteins is associated with HPV infection and cervical cancer progression.

BACKGROUND: Cervical cancer (CeCa) is the second most common cancer in women in developing countries, and human papilloma virus (HPV) is the primary etiological factor. Aberrant expression of HOX transcription factors has been observed in several types of cancer. To date, however, no reports exist on the expression of HOXB2 and HOXB13 proteins during neoplastic progression in CeCa and its correlation with HPV infection. MATERIALS AND METHODS: Expression of HOXB2 and HOXB13 proteins was assessed in tissue microarrays from normal cervical epithelium, cervical intraepithelial neoplasias grade 1-3, and CeCa. HPV was detected by PCR and sequencing. Expression of HOX-positive cells was determined in each diagnostic group. RESULTS: Percentage of HOXB2- and HOXB13-positive cells gradually increased from means of 10.9% and 16.7%, respectively, in samples from healthy women, to 75.2% and 88.6% in those from CeCa patients. Frequency of HPV infection also increased from 13% in healthy tissue samples to 92.3% in CeCa. Both HOXB2 and HOXB13 proteins were preferentially expressed in HPV+ samples. CONCLUSIONS: The present study represents the first report on the expression of both HOXB2 and HOXB13 proteins through cervix tumorigenesis, providing evidence that increased expression of such proteins is a common event during progression to CeCa.

An oligoarray for the detection of human papillomavirus type 16 variants.

On the basis of human papillomavirus (HPV) E6 gene mutations, there are more than five variants of HPV 16. We applied a sensitive and specific stacking hybridization assay using an oligoarray for the detection of Asian-American (AA) and European (E) (E350G) HPV 16 variants. A simple glass slide was coated with capture probes consisting of short oligonucleotide DNA sequences (7-9 mers) specific for AA and E variants. Two different regions of the E6 HPV 16 gene were amplified with a set of two primers, which were used as target DNA. These targets were preannealed with auxiliary labeled oligonucleotides and hybridized to the oligoarray in the presence of specific and complementary capture probes. Our designed array based on shorter capture probes successfully discriminated between HPV 16 AA and E variants. The present DNA oligoarray system could be useful as a reliable technique for HPV 16 detection and does not require specialized equipment; nevertheless, further intra- and interlaboratory studies are needed.

Expression of the costimulatory molecule CD86, but not CD80, in keratinocytes of normal cervical epithelium and human papillomavirus-16 positive low squamous intraepithelial lesions.

Keratinocytes have been traditionally considered as nonprofessional antigen presenting cells, since multipassaged cells from skin biopsies of healthy individuals do not constitutively express major histocompatibility complex (MHC) class II or costimulatory molecules, but can be induced to do so after exposure to interferon-gamma. In normal and human papillomavirus (HPV)-infected cervical epithelium, keratinocytes are affected by a variety of soluble mediators that could modulate the expression of molecules including costimulatory proteins; however, the presence of these molecules within the cervix has been poorly studied. Therefore, our aim was to further explore the presence of costimulatory molecules on normal cervical epithelium and HPV-16 positive low squamous intraepithelial lesions (LSIL). We found in situ CD86 (but not CD80) displayed on the surface of normal keratinocytes from the spinous layer of human cervical epithelium. The presence of the protein and its messenger RNA level (evaluated by in situ hybridization) was diminished in HPV-16 positive LSILs. Although downregulation of costimulatory molecules is frequently related to cytokines expression, we did not observe differences in the presence of interleukin-10, the main cytokine that inhibits CD86 expression. Expression of CD86 on keratinocytes from normal cervical epithelium could indicate the potentiality of these cells to activate cytotoxic T cells, while the shut-off of this molecule in HPV-16 positive lesions could be a mechanism for evading host immune surveillance, resulting in the persistent HPV infection and probable progression of cervical lesions.

Differentially expressed genes between high-risk human papillomavirus types in human cervical cancer cells.

Cervical carcinoma (CC) is one of the most common cancers among women worldwide and the first cause of death among the Mexican female population. Human papillomavirus (HPV) infection is the most important etiologic factor for CC. Of the oncogenic types, HPV16 and HPV18 are found in 60-70% of invasive CCs worldwide. HPV18 appears to be associated with a more aggressive form of cervical neoplasia than HPV16 infection. At present, there are no studies on differentially expressed cellular genes between transformed cells harboring HPV16 and HPV18 sequences. Based on previous complementary DNA microarray data from our group, 13 genes were found to be differentially overexpressed between HPV16- and HPV18-transformed cells. These genes were as follows: E6BP, UBE4A, C20orf14, ATF7, ABCC8, SLC6A12, WASF3, SUV39H1, SPAG8, CCNC, E2FFE, BIRC5, and DEDD. Differential expression of six selected genes was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). All real-time RT-PCRs confirmed differential expression between HPV18 and HPV(-) samples. The present work identifies genes from signaling pathways triggered by HPV transformation that could be differentially deregulated between HPV16(+) and HPV18(+) samples.

Human papillomavirus-specific viral types are common in Mexican women affected by cervical lesions.

Cervical cancer (CC) is the most common in Mexican female population. The human papillomavirus (HPV) 16 and 18 frequencies in worldwide may be different due to geographical distribution. We analyzed the prevalence of HPV types and determinated their association in cervical lesion in a Mexican population. One hundred fifty-nine normal cervical smears, 95 low-grade squamous intraepithelial lesions (LGSIL), 59 high-grade squamous intraepithelial lesions (HGSIL), and 108 CC samples of the patients were collected. HPV types were determined by sequencing. We detected 11 high-risk types, four low-risk types, three not determinated, and two probably high risk. HPV were present in 12%, 57%, 88%, and 92% from normal, LGSIL, HGSIL, and CC samples, respectively. HPV 16 was the most common in all cervical lesions (71.6% in CC). HPV 58 was present in 18.6% of HGSIL, and the HPV 18 in 4.6% of CC. The 76% of all detected viruses belong to A9 species branch. Control women showed high percentage of HPV high-risk infection, suggesting that this is a high-risk group. High frequency of HPV 16 compared with a low incidence of HPV 18 was observed. HPV 58 is frequently detected in HGSIL but low frequency is found in CC. These findings might be considered for HPV screening.