MODULATION OF MDR-1 GENE BY MIF AND GSTpi WITH DRUG RESISTANCE GENERATION IN HORMONE INDEPENDENT PROSTATE CANCER

Trichomonas vaginalis homolog of macrophage migration inhibitory factor induces prostate cell growth, invasiveness, and inflammatory responses

The human-infective parasite Trichomonas vaginalis causes the most prevalent nonviral sexually transmitted infection worldwide. Infections in men may result in colonization of the prostate and are correlated with increased risk of aggressive prostate cancer. We have found that T. vaginalis secretes a protein, T. vaginalis macrophage migration inhibitory factor (TvMIF), that is 47% similar to human macrophage migration inhibitory factor (HuMIF), a proinflammatory cytokine. Because HuMIF is reported to be elevated in prostate cancer and inflammation plays an important role in the initiation and progression of cancers, we have explored a role for TvMIF in prostate cancer. Here, we show that TvMIF has tautomerase activity, inhibits macrophage migration, and is proinflammatory. We also demonstrate that TvMIF binds the human CD74 MIF receptor with high affinity, comparable to that of HuMIF, which triggers activation of ERK, Akt, and Bcl-2-associated death promoter phosphorylation at a physiologically relevant concentration (1 ng/mL, 80 pM). TvMIF increases the in vitro growth and invasion through Matrigel of benign and prostate cancer cells. Sera from patients infected with T. vaginalis are reactive to TvMIF, especially in males. The presence of anti-TvMIF antibodies indicates that TvMIF is released by the parasite and elicits host immune responses during infection. Together, these data indicate that chronic T. vaginalis infections may result in TvMIF-driven inflammation and cell proliferation, thus triggering pathways that contribute to the promotion and progression of prostate cancer.

Elevated expression of macrophage migration inhibitory factor correlates with tumor recurrence and poor prognosis of patients with gliomas

Macrophage migration inhibitory factor (MIF) plays a critical role in tumorigenesis. We aim to examine the association of MIF with tumor recurrence and survival of gliomas, and to determine whether MIF is a valuable prognostic predictor for glioma patients. The expression of MIF and interleukin 8 (IL-8) was evaluated in 36 high-grade gliomas (20 glioblastoma multiforme, 13 anaplastic astrocytoma, and 3 anaplastic oligoastrocytoma) and 32 low-grade gliomas (18 fibrillary astrocytoma, 5 pilocytic astrocytoma, 5 oligodendroglioma, 3 ependymoma and 1 pleomorphic xanthoastrocytoma) by immunostaining. Intratumoral microvessel density (IMD) of tumors in relation to immunostainings and clinicopathological factors were analyzed statistically as well as the follow-up data of patients. High expression of both MIF (58.8%) and IL-8 (52.9%) was significantly associated with high-grade gliomas and increased microvessels in tumors, but only high expression of MIF was closely related to tumor recurrence (P = 0.001). High expression of IL-8 exhibited a close correlation with high expression of MIF in tumors (P = 0.001). Histological grading, high expression of MIF and IL-8 correlated with patients' overall survival in univariate analysis. However, only histological grading and MIF expression exhibited a relationship with survival of patients as independent prognostic factors of glioma by multivariate analysis; the hazard ratios were 28.012 (P = 0.001) and 11.782 (P = 0.001), respectively. Elevated production of MIF in glioma tumor cells may contribute to tumor recurrence and a worse prognosis. MIF may serve as an independent predictive factor for prognosis of glioma patients.

Macrophage migration inhibitory factor contributes angiogenesis by up-regulating IL-8 and correlates with poor prognosis of patients with primary nasopharyngeal carcinoma

BACKGROUND AND OBJECTIVES

We aim at the association of macrophage migration inhibitory factor (MIF) with neovascularization and survival of nasopharyngeal carcinoma (NPC), and determine whether MIF is a valuable prognostic predictor for NPC patients.

METHODS

One hundred and forty one cases of NPC and 25 normal tissues of nasopharynx were collected. The expression of MIF and interleukin 8 (IL-8) was evaluated in tissues microarray by immunostaining. Intratumoral microvessel density (IMD) in relation to immunostainings and clinicopathological factors were analyzed statistically as well as the follow-up data of patients.

RESULTS

High-expression of both MIF (69.5%) and IL-8 (56.0%) were significantly associated with increased microvessels and lymph node metastasis. High-expression of MIF, IL-8 and higher level of IMD were correlated with either patients' overall survival or disease-specific survival in univariate analysis, but only angiogenesis and lymph node status exhibited in relation to survival of patients as independent prognostic factor of NPC by multivariate analysis. In addition, high-expression of MIF and higher level of IMD were closely associated with locoregional failure of NPC patients.

CONCLUSIONS

MIF may contribute to lymph node metastasis in NPC by inducing angiogenesis through the way of upregulation of IL-8 expression in an autocrine EBV-independent pathway.

Macrophage migration inhibitory factor expression in cervical cancer

PURPOSE

The glycoprotein macrophage migration inhibitory factor (MIF) is a cytokine that has been shown to promote tumor progression and tumor immune escape in ovarian cancer. The present study investigates MIF in uterine cervical cancer.

METHODS

Eighty surgical biopsies (32 cervical dysplasias, 23 in situ carcinomas and 25 invasive carcinomas) of uterine cervical tissue were evaluated immunohistochemically for MIF expression. In uterine cervical cancer cell lines SiHa and CaSki and their respective supernatants, MIF protein expression was analyzed by Western blotting, enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Immunohistochemical analysis shows that MIF is clearly overexpressed on the protein level in invasive cervical cancer compared to cervical dysplasias. MIF overexpression was confirmed by RT-PCR in surgical biopsies of invasive cervical cancer. Western blotting reveals that the MIF protein is overexpressed in SiHA und CaSki cervical cancer cell lines, whereas the ELISA reveals that cervical cancer cells secrete MIF.

CONCLUSIONS

MIF has been shown to promote tumor immune escape mechanisms in other cancer entities, which makes it an interesting target for cancer therapy, given the known significance of immune mechanisms for uterine cervical cancer. The overexpression of MIF on the protein and mRNA level, as well as its secretion by cervical cancer cells points to a critical role of the protein for the pathogenesis of uterine cervical cancer.

Association of GSTP1 expression with resistance to docetaxel and paclitaxel in human breast cancers

AIMS

It has been reported that glutathione S-transferase P1 (GSTP1) expression is implicated in resistance to taxanes (docetaxel and paclitaxel) in human breast cancer cells in vitro. In the study presented here, we examine whether GSTP1 expression is associated with resistance to docetaxel or paclitaxel in human breast cancers. We also investigated the relationship between GSTP1 methylation status and response to these taxanes.

MATERIAL AND METHODS

Sixty two primary breast cancer patients were treated with docetaxel or paclitaxel as primary systemic treatment (PST). GSTP1 expression was detected immunohistochemically and the hypermethylation status GSTP1 gene was identified with a methylation specific primer assay.

RESULTS

The mean tumor reduction rate for all patients (n=62) was significantly (p<0.001) higher in GSTP1 negative (0.73+/-0.04; mean+/-standard error) than GSTP1 positive (0.31+/-0.09) tumors. The subset analysis showed that the mean reduction rate was significantly (p=0.005) higher in GSTP1 negative (0.59+/-0.06) than GSTP1 positive (0.11+/-0.13) tumors in the docetaxel group as well as in the paclitaxel group (p=0.006; GSTP1 negative tumors: 0.84+/-0.05; GSTP1 positive tumors: 0.56+/-0.08). On the other hand, GSTP1 methylation showed no significant association with the reduction rate.

CONCLUSION

Our present study has suggested that GSTP1 protein expression, but not GSTP1 methylation status, might be associated with response to docetaxel and paclitaxel. This suggests that GSTP1 immunohistochemical expression might be a potentially clinically useful predictive factor for response to docetaxel and paclitaxel.