Up and away with cervical cancer: IL-29 is a promising cytokine for immunotherapy of cervical cancer due to its powerful upregulation of p18, p27, and TRAILR1

Cervical cancer is one of the most common types of female cancers worldwide. IL-29 is an interesting cytokine in the IFNλ family. Its role in the pathogenesis of neoplasia is complicated and has been studied in other cancers, such as lung cancer, gastric cancer, and colorectal cancer. IL-29 has been previously reported to promote the growth of pancreatic cancer. However, the direct role of IL-29 in cervical cancer has not been studied yet. This study was performed to investigate the direct effect on cervical cancer cell growth. Clonogenic survival assay, cell proliferation, and caspase-3 activity kits were used to evaluate the effects of IL-29 on cell survival, proliferation, and apoptosis of a well-studied cervical cancer cell line, SiHa. We further investigated the potential molecular mechanisms by using RT-PCR and IHC. We found that the percentage of colonies of SiHa cells was decreased in the presence of IL-29. This was consistent with a decreased OD value of cancer cells. Furthermore, the relative caspase-3 activity in cancer cells increased in the presence of IL-29. The anti-proliferative effect of IL-29 on cancer cells correlated with increased expression of the anti-proliferative molecules p18 and p27. The pro-apoptotic effect of IL-29 on cancer cells correlated with increased expression of the pro-apoptotic molecule TRAILR1. IL-29 inhibits cervical cancer cell growth by inhibiting cell proliferation and promoting cell apoptosis. Thus, IL-29 might be a promising cytokine for immunotherapy of cervical cancer.

Harnessing the Power of Kiwifruit for Radiosensitization of Melanoma

BACKGROUND

Melanoma is the deadliest variant of skin cancer and its incidence continues to increase. There are limited treatment options for advanced and metastatic cases of melanoma, despite advances in immunotherapy and chemotherapy. Melanoma is notorious as a radioresistant tumor. Previous studies found that phytochemicals, such as resveratrol and those found in green tea and blueberry, can sensitize various cancer cells, including melanoma, to radiotherapy. Our previous study also revealed that kiwifruit extract (KE) has antitumor activity to melanoma cells. This study was designed to expand upon our previous investigation and determine KE's potential as a radiosensitizer on CRL-11147 melanoma cancer cells and elucidate the possible mechanisms behind its potential.

MATERIALS AND METHODS

Proliferation and apoptosis of CRL-11147 melanoma cells under radiation therapy (RT) plus KE versus RT alone were investigated using Proliferative cell nuclear antigen (PCNA) staining, quick cell proliferation assay, clonogenic assay, and caspase-3 activity assay. Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were then used to investigate the mechanisms behind the observed results.

RESULTS

The percentage of CRL-11147 colonies, PCNA staining intensity, and the optic density value of CRL-11147 cells decreased with RT/KE vs. RT alone. Relative caspase-3 activity was increased with RT/KE vs. RT alone. Increased expression of the anti-proliferative molecule p27 and pro-apoptotic molecule TRAILR1 correlated with the anti-tumor effect seen in the RT/KE group versus the RT alone group.

CONCLUSION

KE augments radiosensitivity of CRL-11147 by up-regulating both p27 and TRAILR1 to inhibit proliferation and increase apoptosis, respectively.

Potential use of kiwifruit extract for treatment of melanoma

Skin cancers are the most common cancers in the world and among the different types of skin cancers, melanoma is the deadliest and incidence is rising. Previous studies have shown promising in vitro and human evidence of kiwifruit exhibiting anti-cancer effects. This study was designed to investigate if kiwifruit extract (KE) has any effect on CRL-11147 melanoma cancer cells and to investigate the possible mechanisms behind the results. The effects of KE on CRL-11147 melanoma cell survival, proliferation, and apoptosis was investigated using clonogenic survival assay, cell proliferation, and caspase-3 activity kits. Potential anti-tumor molecular mechanisms were elucidated using RT-PCR and IHC. Addition of KE decreased CRL-11147 cell colonies percentages indicated by a decreased optical density value of cancer cells when compared to control. Furthermore, treatment with KE increased relative caspase-3 activity in cancer cells, which indicated increased apoptosis of cancer cells. The anti-proliferative effect of KE on cancer cells corresponded with decreased expression of the pro-proliferative molecule Cyclin E and CDK4, while increased expression of the pro-apoptotic molecule TRAILR1 corresponded with the pro-apoptotic effect. KE decreases CRL-11147 melanoma cell growth via downregulation of Cyclin E and CDK4 and upregulation in TRAILR1. Our study suggests a potential use for KE in treatment of melanoma.

TRAF2 Controls Death Receptor-Induced Caspase-8 Processing and Facilitates Proinflammatory Signaling

Tumor necrosis factor (TNF) receptor associated factor-2 (TRAF2) knockout (KO) cells were generated to investigate the role of TRAF2 in signaling by TNFR1 and the CD95-type death receptors (DRs) TRAILR1/2 and CD95. To prevent negative selection effects arising from the increased cell death sensitivity of TRAF2-deficient cells, cell lines were used for the generation of the TRAF2 KO variants that were protected from DR-induced apoptosis downstream of caspase-8 activation. As already described in the literature, TRAF2 KO cells displayed enhanced constitutive alternative NFκB signaling and reduced TNFR1-induced activation of the classical NFκB pathway. There was furthermore a significant but only partial reduction in CD95-type DR-induced upregulation of the proinflammatory NFκB-regulated cytokine interleukin-8 (IL8), which could be reversed by reexpression of TRAF2. In contrast, expression of the TRAF2-related TRAF1 protein failed to functionally restore TRAF2 deficiency. TRAF2 deficiency resulted furthermore in enhanced procaspase-8 processing by DRs, but this surprisingly came along with a reduction in net caspase-8 activity. In sum, our data argue for (i) a non-obligate promoting function of TRAF2 in proinflammatory DR signaling and (ii) a yet unrecognized stabilizing effect of TRAF2 on caspase-8 activity.

Trichomonas Vaginalis Inhibits HeLa Cell Growth Through Modulation of Critical Molecules for Cell Proliferation and Apoptosis

BACKGROUND/AIM

Cervical cancer is one of the deadliest gynecological cancers in USA. The role of Trichomonas Vaginalis (T. Vag) in the etiology or pathogenesis of cervical cancer is still poorly understood and controversial.

MATERIALS AND METHODS

Clonogenic assay, PCNA staining, TUNEL staining and caspase-3 activity assay were used to investigate the direct in vitro effect of T. Vag on human cervical cancer by using HeLa cells. We further investigated the potential molecular mechanisms using RT-PCR and immunohistochemical staining.

RESULTS

We found that culture supernatant of T. Vag inhibited growth of HeLa cervical cancer cells and this correlated with up-regulation of p15. We also found that culture supernatant of T. Vag induced apoptosis of HeLa cells and this correlated with up-regulation of Fas, TRAIL and TRAILR1.

CONCLUSION

Culture supernatant of T. Vag inhibits growth of HeLa cervical cancer cells by inhibition of proliferation and promotion of apoptosis. Our study might be helpful to address the association between the development of cervical cancer and infection of T. Vag.

Crosstalk between apoptosis, necrosis and autophagy

Apoptosis and necrosis are the two major modes of cell death, the molecular mechanisms of which have been extensively studied. Although initially thought to constitute mutually exclusive cellular states, recent findings reveal cellular contexts that require a balanced interplay between these two modes of cellular demise. Several death initiator and effector molecules, signaling pathways and subcellular sites have been identified as key mediators in both processes, either by constituting common modules or alternatively by functioning as a switch allowing cells to decide which route to take, depending on the specific situation. Importantly, autophagy, which is a predominantly cytoprotective process, has been linked to both types of cell death, serving either a pro-survival or pro-death function. Here we review the recent literature that highlights the intricate interplay between apoptosis, necrosis and autophagy, focusing on the relevance and impact of this crosstalk in normal development and in pathology. This article is part of a Special Section entitled: Cell Death Pathways.