Role of CC Chemokines Subfamily in the Platinum Drugs Resistance Promotion in Cancer.

Cancer is a significant medical issue, being one of the main causes of mortality around the world. The therapies for this pathology depend on the stage in which the cancer is found, but it is usually diagnosed at an advanced stage in which the treatment is chemotherapy. Platinum drugs are among the most commonly used in therapy, unfortunately, one of the main obstacles to this treatment is the development of chemoresistance, which is the ability of cancer cells to evade the effects of drugs. Although some molecular mechanisms involved in resistance to platinum drugs are described, elucidation is still required of others. Secretion of inflammatory mediators such as cytokines and chemokines, by tumor microenvironment components or tumor cells, show direct influence on proliferation, metastasis and progression of cancer and are related to chemoresistance and poor prognosis. In this review, the general mechanisms associated with resistance to platinum drugs, inflammation on cancer development and chemoresistance in various types of cancer will be approached with special emphasis on the current history of CC chemokines subfamily-mediated chemoresistance.

The Role of Clock Genes in Fibrinolysis Regulation: Circadian Disturbance and Its Effect on Fibrinolytic Activity.

The fibrinolytic system is critical during the onset of fibrinolysis, a fundamental mechanism for fibrin degradation. Both tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) trigger fibrinolysis, leading to proteolytic activation of plasminogen to plasmin and subsequently fibrin proteolysis. This system is regulated by several inhibitors; plasminogen activator inhibitor-1 (PAI-1), the most studied, binds to and inactivates both tPA and uPA. Through the action of plasmin, this system regulates several physiological processes: embryogenesis, activation of inflammatory cells, cell proliferation and death, synaptic plasticity, wound healing, and others. The deregulated intervention of fibrinolysis in the pathophysiology of various diseases has been widely studied; findings of altered functioning have been reported in different chronic non-communicable diseases (NCD), reinforcing its pleiotropic character and the importance of its physiology and regulation. The evidence indicates that fundamental elements of the fibrinolytic system, such as tPA and PAI-1, show a circadian rhythm in their plasmatic levels and their gene expression are regulated by circadian system elements, known as clock genes - Bmal, Clock, Cry-, and accessory clock genes such as Rev-Erb and Ror. The disturbance in the molecular machinery of the clock by exposure to light during the night alters the natural light/dark cycle and causes disruption of the circadian rhythm. Such exposure affects the synchronization and functioning of peripheral clocks responsible for the expression of the components of the fibrinolytic system. So, this circadian disturbance could be critical in the pathophysiology of chronic diseases where this system has been found to be deregulated.

Effects of c-FLIPL knockdown in cervical uterine carcinoma cell lines / Efectos de la inhibición de C-Flipl en líneas celulares de cáncer de cuello uterino

Overexpression of Short and Raji variants of Cellular FLICE-like inhibitory protein (c-FLIP) is capable of inhibiting apoptosis, while the function of the Long isoform depends of c-FLIPL concentration in cells. The aim of this study was to determine the effects of c-FLIPL knockdown in cervical cell lines. SiHa, C-4I and C-33A cervical cancer cell lines were analyzed. c-FLIPL level expression was determined by quantitative real-time PCR and western blotting. c-FLIPL was transiently downregulated by siRNA. The effects of knockdown of c-FLIPL on cell viability, proliferation and apoptosis were assessed by comparing with scrambled siRNA-transfected cells. SiHa and C-4I c-FLIPL knockdown cells showed increased viability compared with scrambled siRNA-transfected cells (P<0.05), while C-33A cells did not show significant differences. Ki-67 and PCNA immunocytochemistry was performed to evaluate proliferation on these cervical cancer cell lines. SiHa cells with c-FLIPL knockdown showed elevated expression of Ki-67 protein compared with their scrambled counterparts (P<0.0001), while C-33A c-FLIPL knockdown cells showed a significantly lower in PCNA expression (P<0.01) compared with control. All three c-FLIP-transfected cell lines showed a higher level of apoptosis compared with their scrambled controls. Our results suggest that c-FLIPL could have effects in proliferation and apoptosis in cervical cancer cell lines.

Cuando las variantes Short y Raji de la proteína Cellular FLICE-like inhibitory protein (c-FLIP) se encuentran sobrexpresadas son capaces de inhibir la apoptosis, mientras la función de la isoforma Long (c-FLIPL), depende de la concentración de esta molécula en las células. El objetivo de este estudio fue determinar los efectos de la inhibición de c-FLIPL en líneas celulares de cáncer de cuello uterino. Para realizar el estudio fueron utilizadas SiHa, C-4I y C-33A, líneas celulares de cáncer cervical. La expresión de c-FLIPL en estas líneas fue establecida mediante PCR en tiempo real y western blot. Posteriormente la expresión de c-FLIPL fue inhibida, mediante transfeción transiente con siRNA complementario al mRNA mensajero de c.-FLIPL. Los efectos de esta inhibición en la viabilidad celular, proliferación y apoptosis fue comparada con células transfectadas con un siRNA control (scrambled). Una vez reprimido c-FLIPL, las líneas celulares SiHa y C-4I presentaron un aumento de la viabilidad celular (P<0,05). Para evaluar la proliferación celular se utilizó inmunocitoquímica de los marcadores Ki-67 y PCNA. Las células SiHa transfectadas con siRNA c-FLIPL, mostraron una elevada expresión de Ki-67 (P<0,0001), mientras que las células C-33A con c-FLIPL inhibido mostraron una menor expresión de PCNA (P<0,01). Las tres líneas celulares con c-FLIPL reprimido mostraron un mayor nivel de apoptosis que las células control. Estos resultados sugieren que c-FLIPL puede tener efectos en la proliferación y apoptosis de líneas celulares de cáncer de cuello uterino.

Frecuencia de virus papiloma humano en tumores no ginecológicos de la Región de la Araucanía, Chile / Human papilloma virus frequency in non-gynecological tumors in the Araucanía Region, Chile

El Virus Papiloma Humano (HPV por sus siglas en inglés) es una de las infecciones de transmisión sexual más frecuentes del mundo y se encuentra presente en la mayoría de los cánceres de cuello uterino. Se ha descrito su presencia en otros tipos de cáncer no ginecológicos como lo son esófago y próstata. Sin embargo, las frecuencias de HPV descritas hasta el momento para estos tipos de cáncer son muy variables, y no hay artículos donde se muestren la presencia de HPV en estas neoplasias en Chile. El objetivo de este estudio fue determinar la frecuencia de HPV en muestras de biopsias de tumores no ginecológicos y tejido inflamatorio de pacientes de la región de La Araucanía. Se extrajo DNA desde un total de 47 biopsias de pacientes con esofagitis, 25 con carcinoma escamoso esofágico, 20 con hiperplasia nodular de la próstata y 39 con adenocarcinoma prostático. Estas fueron analizadas por PCR de la región L1 del virus y posterior genotipificación por reverse line blot. Se detectó HPV en el 53,2% de las muestras de esofagitis, 48% en muestras de carcinoma escamoso esofágico, 15% en hiperplasia nodular de la próstata y un 15,4% en los casos de adenocarcinoma prostático. Siendo los más frecuentes los genotipos de HPV 16 y 18, ya sea en infecciones simples o junto con otros genotipos, en lesiones preneoplásicas y neoplásicas de los tejidos estudiados. Existe una alta frecuencia de infección por HPV en biopsias de esofagitis y tejido inflamatorio esofágico de pacientes de la región de la Araucanía. En los casos de adenocarcinoma prostático e hiperplasia nodular de la próstata se observa una baja frecuencia de HPV.

Human Papilloma Virus (HPV) is the most common sexually transmitted disease in the world and it is present in practically all cervical cancers. Its presence was described in other types of non-gynecologic cancer such as esophageal and prostate. However, HPV frequency described for these cancers is highly variable, and there are no articles describing the presence of HPV in these tumors in Chile. To determine HPV frequency in samples from biopsies of non-gynecological tumors and inflammatory tissue from patients in the Araucanía region, DNA was extracted from a total of 47 biopsies from patients with esophagitis, 25 with esophageal squamous cell carcinoma, 20 with prostate nodular hyperplasia and 39 with prostate adenocarcinoma. These were analyzed by PCR of HPV L1 region and subsequent genotyping by reverse line blot. HPV was detected in 53.2% of esophagitis samples, 48% in esophageal squamous cell carcinoma, 15% in prostatitis and 15.4% in cases of prostatic adenocarcinoma. The most frequent HPV genotypes were 16 and 18, either single or in combination with other genotype infections, in inflammatory tissue and neoplastic lesions. In patients of the Araucanía region, there is a high rate of HPV infection in biopsies obtained in esophagitis and esophageal inflammatory tissue. In cases of prostatic adenocarcinoma and prostate nodular hyperplasia a low rate of HPV was observed.

Genotyping of human papillomavirus in cervical intraepithelial neoplasia in a high-risk population.

Infection with the human papillomavirus (HPV) is responsible for 99.7% of cervical cancers, the second most prevalent neoplasia in women worldwide and the fifth leading cause of death by cancer in this population. In Chile, the incidence rate is 14.4 cases per 100,000 women per year and it is considered a significant public health problem. The natural history of cervical cancer begins gradually from low-grade and high-grade squamous intraepithelial lesions to an invasive disease. In this study the frequency of HPV types was determined by HPV genotyping with reverse line blot hybridization in 200 cytobrushes of women with preneoplastic lesions in a high-risk population. HPV DNA was found in 89% of the lesions (83.3% of low-grade squamous intraepithelial lesions and 93.6% of high-grade squamous intraepithelial lesions). Multiple HPV infections were found in 14.4% and 15.5% of low- and high-grade lesions, respectively. HPV 16 was the most frequent genotype in single infections, followed by HPV 18. These results show that most of the preneoplastic lesions of the cervix (60%) were associated with HPV 16 and/or HPV 18, supporting the implementation of an HPV vaccination program in this high-risk population.