**8. Conclusion**

*Cutaneous Melanoma*

melanoma growth:

**Figure 4.**

**7. Summary**

melanoma cells [43].

cell in nude mouse [45].

**6.1 Involvement of IL-8 in melanoma growth**

In vivo and in vitro studies from other labs showed the involvement of IL-8 in

*Biochemical basis of progesterone action. An ELISArray, containing pro- and anti-inflammatory cytokine antibodies coated in different wells, showed a specific suppression of IL-8 cytokine alone in the supernatant of* 

*cells treated with progesterone (50 μM) compared to untreated control cell supernatant.*

1.IL-8 cytokine produced in vitro was an essential autocrine growth factor for

2.Expression of IL-8 in human melanoma cells upregulated the activity of matrix metalloproteinase (MMP) and increased tumor growth and metastasis [44].

3.Expression of IL-8 correlated with metastatic potential of human melanoma

In vivo and in vitro studies showed the inhibition of melanoma growth by various hormones. This inhibition of cell growth by various hormones suggested that melanoma could be a hormone-responsive cancer, where hormones were essential for survival in melanoma. This was supported by the clinical studies carried out in the 1950s and 1960s. One clinical study reported that menstruating females were better protected in melanoma than postmenopausal women and men of any age [20]. But, the study did not correlate with steroid status of females. Literature showed that progesterone level peaked in menstruating females between 1000 and

1500 ng/dl, whereas progesterone level ranged between 20 and 100 ng/dl in postmenopausal women [46]. Our research also showed that progesterone inhibited human melanoma (BLM) cell growth in vitro significantly. In addition, progesterone inhibitory action was also shown by Fang et al., Moroni et al., and Kanda and Watanbe. So, it was hypothesized that progesterone could be protecting menstruating females. Recently, it was shown that the protective function of progesterone was mediated by a specific suppression of pro-inflammatory cytokine IL-8. Various in vitro and in vivo studies already showed the importance of IL-8 in

**48**

melanoma cell growth.

Several studies showed the involvement of progesterone in the regulation of in vitro melanoma cell growth and also in the regulation of in vivo melanoma growth. Further in vitro research showed that the progesterone inhibitory action was mediated by a specific suppression of pro-inflammatory cytokine IL-8. The connection between IL-8 and melanoma growth was already established by other investigators. This brought IL-8 into focus in melanoma and suggested that IL-8 could be considered as a potential target for melanoma treatment.
