The evaluation of human endogenous retroviral env expression in normal and cancerous tissues of the breast.

Background: Both internal and external risk factors can accelerate the progression of breast cancer which is the reason why clinicians have tried to find new biomarkers for this health problem. Human endogenous retrovirus-W (HERV-W) can be one of these biomarkers, as it has been mentioned that some genes of this virus are able to have either higher or lower expression in numerous cancerous cells. In this study, we aimed to compare HERV-W envelope expression in breast cancer tissues and normal ones since its effects on this malignancy have not been clear. Materials and Methods: We collected 46 breast cancer tissues and their normal adjacent ones. After extracting the RNA of breast samples, we evaluated the expression of HERV-W envelope syncytin-1 and 2 using quantitative real-time polymerase chain reaction (PCR) in different kinds of breast cancer stages. Results: Data showed that more than 13% of patients had a family history of breast cancer; moreover, approximately half of the tissues were estrogen receptor or progesterone receptor positive. Lymph node metastasis was seen in 52% of the patients, and about 40% of tumors were larger than 2 cm. Real-time PCR showed that syncytin-1 and 2 had upward regulation with (*P < 0.05) and (**P < 0.01), respectively. Conclusion: As the expression of HERV-W Env (syncytin-1, syncytin-2) was higher in breast cancerous tissues in comparison with normal ones, we believe that these genes may have a role to play in monitoring patients suffering from this type of cancer. However, further studies are needed to confirm this hypothesis.

Role of the VEGF in virus-associated cancers.

The role of numerous risk factors, including consumption of alcohol, smoking, having diet high in fat and sugar and many other items, on caner progression cannot be denied. Viral diseases are one these factors, and they can initiate some signalling pathways causing cancer. For example, they can be effective on providing oxygen and nutrients by inducing VEGF expression. In this review article, we summarised the mechanisms of angiogenesis and VEGF expression in cancerous tissues which are infected with oncoviruses (Epstein-Barr virus, Human papillomavirus infection, Human T-lymphotropic virus, Kaposi's sarcoma-associated herpesvirus, Hepatitis B and hepatitis C virus).

Low presence of papillomavirus and its lack of correlation with clinicopathological factors in breast cancer: a case control study.

Background and Objectives: Breast cancer is currently the most commonly diagnosed neoplasm in women worldwide. There is evidence that human papillomavirus (HPV) infection may play a key role in breast cancer aggressiveness, but results are conflicting across studies. The aim of this study was to investigate the presence of the HPV viral genome in benign and malignant breast tissue samples and its clinicopathological characteristics of cancer. Materials and Methods: In this case-control study, 100 formalin-fixed paraffin-embedded (FFPE) of breast cancer and 100 blocks of non-cancerous breast tissue were selected as a control group from the pathology department of Imam Khomeini Hospital in Ahvaz from 2020-2022. The presence of HPV was detected using nested PCR including MY09/11 primers and sequencing were performed for virus genotyping. Results: The present study enrolled 100 subjects each in two cancer and control groups with a mean age of 52.81±13.23 and 35.77±11.65, respectively. The risk of cancer in HPV-infected patients is almost 5 times higher than in HPV-negative individuals, it is not statistically significant (OR =4.99, 95% CI 0.35 to 72.15, p=0.238). The prevalence of HPV in the cancer and control groups was 7% and 1%, respectively and HPVs detected in two groups were of the HPV 16 genotype. Although the chance of ER and PR expression, lymphvascular involvement, perineural invasion, and higher tumor grade was higher in HPV-positive subjects than in HPV-negative subjects, this was not statistically significant (OR>1, p>0.05). Conclusion: Based on studies reporting the existence of sequences of different high-risk HPV types (oncogenes) in breast cancer tissues, this study confirmed the hypothesis of a possible infectious cause in the development of breast cancer. So far, however, the results have been controversial and inconclusive. Further studies with large sample sizes are needed to demonstrate the link between HPV and breast cancer.

The prevalence of varicella zoster virus, herpes simplex virus type 2, and human papillomavirus in breast cancerous tissues and their adjacent ones in Iran.

Background: Breast cancer is the second type of cancer in the world. Some internal and external risk factors, especially infection diseases, can progress breast cancer. As the relation between varicella zoster virus (VZV), human papillomavirus (HPV), herpes simplex virus type 2 (HSV-2), and breast cancer has not been understood, it was attempting to find the effect of these viruses and breast cancer in this study. Materials and Methods: We collected 40 breast cancer and 50 healthy adjacent tissues from Taleghani and Imam Hossein Hospital, Tehran, Iran, in 3 years starting in 2017. After extracting DNA from breast tissues, multiplex polymerase chain reaction (PCR), nested PCR, and PCR were done to analyze the prevalence of HSV-2, VZV, and HPV. Results: Our results showed that HPV may be one of the important causes of breast cancer. Nested PCR illustrated nine breast cancerous tissues (mean age: 43) and three healthy adjacent ones (mean age: 41) were infected by HPV. Phylogenetic analysis illustrated that all of the infected HPV cancerous and healthy tissues were HPV 18 (except two healthy samples infected with HPV 6). Nevertheless, there were not any infected tissues by HSV-2 and VZV. Conclusion: It seems that HPV virus type 18 can have high prevalence in breast cancerous tissues in comparison with healthy adjacent ones, and it is likely to have an effect on breast cancer progression. However, the opposite trend is true for HSV-2 and VZV as we did not find any differences between different kinds of breast tissues.

Human Respiratory Syncytial Virus and Coronavirus Rates in Iranian Elderly Patients More than 60 Years Old with Acute Respiratory Symptoms.

Background: Scientists have believed that a number of risk factors, especially viral infectious agents, can be related to respiratory diseases. Due to the pandemics in 2019, Human Respiratory Syncytial Virus and Coronavirus have attracted the attention of different kinds of research. In this study, we attempted to evaluate the prevalence of these viruses. Materials and Methods: After extracting the RNA and DNA of these viruses, molecular tests were employed to report the rate of them in patients suffering from respiratory symptoms. Results: Our results demonstrated that 31 samples were COVID-19 positive. Furthermore, two cases had Respiratory syncytial virus (RSV) subgroup A infections. However, no cases showed a coinfection of both viruses. Conclusions: It seems that during the pandemic of COVID-19, RSV should not be ignored as it can be responsible for the respiratory syndrome.

The Evaluation of HERV-K np9, rec, gag Expression in Isolated Human Peripheral Blood Mononuclear Cell (PBMC) of Gastric and Colon Cancer.

Background: In the current age of diagnostic approaches in cancer, countless efforts have been allocated to identify novel and efficient biomarkers to detect cancer in its early stages. We focused on evaluating the correlation between the progression of gastrointestinal cancer, a leading cause of cancer death worldwide, and human endogenous retrovirus (HERV). Materials and Methods: In this study, we conducted a study on the peripheral blood mononuclear cells (PBMC) gathered from gastric and colon cancer patients. We focused on HERV-K rec, np9, gag expression analysis by quantitative real-time PCR, after extraction of RNA and synthesizing cDNA. Results: Unlike np9 whose expression increased significantly in the colon and gastric cancers, the mRNA level of the rec gene declined in both cancers. Moreover, our data illustrated that the over-expression of the gag gene was only observed in colon cancerous cells rather than gastric malignancy. Conclusions: Overall, given the correlation between the expression level of HERV-associated genes and gastrointestinal cancer, our study suggests that these genes could be considered beneficial markers for cancer diagnosis. However, researchers should conduct studies in future articles on whether these genes can be employed as biomarkers in gastrointestinal cancer.

Detection of HSV-1, HSV-2 and VZV Isolated from Cerebrospinal Fluid Samples of Children Suspected to Encephalitis.

Background: Encephalitis is an uncommon, serious brain infection that can cause fatality among children. The cause of most encephalitis remained unknown, yet viruses are the most well-known infectious agents that cause encephalitis. This study aimed to determine varicella-zoster virus (VZV) and herpes simplex virus type 1, 2 (HSV1/2) among individuals who are under 5 years of age in Iran. Materials and Methods: In this study, 149 cerebrospinal fluid samples of suspected patients of encephalitis were analyzed with some symptoms, such as seizure, fever, nausea loss of consciousness, and dizziness from Mofid Children's Hospital in Tehran, Iran. Then, the molecular evaluation of samples was performed using multiplex Polymerase Chain Reaction (PCR) for detecting HSV1/2 and VZV. Results: The mean age of the patients was 1.8 years. Also, 63.4% of children were male and 36.6% were female. Out of 149 tested samples, 11 (7.3%) showed the viral DNA for one of the herpes viruses (7.3%). Nine samples were HSV1 positive (6.0%) and two samples were VZV positive (1.3%). Fever and vomiting were the most frequent symptoms. The mean ± standard deviation (SD) WBC and counts in cerebrospinal fluid (CSF)-positive samples, and all included samples were 298.8 ± 552.7 cells/µL and 131.1 ± 474.6 cells/µL, respectively. Conclusions: Although viral encephalitis is considered a threat to children's health, with accurate diagnosis and appropriate antiviral drugs, death and neurological complications in children can be prevented.

Prevalence of Human Papillomavirus and Co-Infection with Epstein-Barr Virus in Oral and Oropharyngeal Squamous Cell Carcinomas.

BACKGROUND: Head and neck squamous cell carcinoma is one of the most important malignancies, worldwide. Oncogenic viruses, such as human papilloma virus (HPV) and Epstein-Barr virus (EBV), are linked to these cancers and studies suggest a possible interaction between HPV and EBV during co-infections to promote oncogenesis. Nonetheless, these reports are controversial and demand more investigations in this regard. The present work to assessed the prevalence of HPV and co-infection with EBV in oral and oropharyngeal squamous cell carcinomas. METHODS: Formalin-fixed paraffin-embedded tissues were collected from 166 archived oral and oropharyngeal squamous cell carcinoma samples from Ahvaz Imam Khomeini hospital, Ahvaz, Iran, from March 2013 and December 2019. Nested-PCR was used to detect the viruses and type-specific PCR/nested-PCR and sequencing were performed for virus genotyping. RESULTS: Out of the 166 specimens, 84.33% and 16.42% were from oral cavity and oropharynx, respectively; of which, 32 cases (19.3%) were HPV-positive (16.42% of oral cavity and 34.6% of oropharynx). HPV was detected in 36.36%, 25%, and 16.42% of base of tongue, tonsil, and oral tongue tumors, respectively. HPV was more associated with well differentiated tumors (24;18.04%) in compared to moderately and poorly differentiated ones. Regarding HPV-16 genotyping, 7 (21.8%) out of the 32 samples were found to be HPV-16 (4/26 (15.38%) for oropharynx and 3/140 (2.14%) for oral cavity). Moreover, 90 samples were evaluated for EBV infection and co-infection; of which, 4 (4.4%) subjects tested positive for EBV, including two cases with HPV co-infection. All the positive cases were EBV type B, from oral cavity, and histologically well differentiated. CONCLUSIONS: HPV was more associated with oropharyngeal cancer. This association has been linked to various factors such as repeated oral and oropharyngeal exposure to HPV due to change in patterns of sexual behaviors; a phenomenon that may demand routine HPV vaccination.

Detection of Major Human Herpesviruses in Iranian Patients with Suspected Encephalitis Using Multiplex Polymerase Chain Reaction.

BACKGROUND: The Herpesviridae family plays a significant etiological role in central nervous system viral infections during primary infection or reactivation from a latent form. Early detection is crucial because prescribing some antivirals can prevent severe side effects or life-threatening conditions. METHODS: In this study, 251 CSF specimens were collected from patients with clinical suspicion of viral encephalitis in Pars Hospital, Tehran, Iran. DNA was extracted, and a multiplex PCR was designed to investigate the presence of herpes simplex virus-1, herpes simplex virus-2, varicella zoster virus, Epstein-Barr virus, and cytomegalovirus. RESULTS: Overall, 59 cases of the 251 CSF samples were positive for multiplex PCR (23.5%). The most frequent positive findings were EBV and HSV, with a prevalence of 10.3% and 8.7% (5.5% HSV-1 and 3.1% HSV-2), respectively. Four co-infections were also seen in this study. CONCLUSIONS: This multiplex PCR assay detects simultaneously different herpesviruses in CSF samples of patients with suspected encephalitis in 2 rounds of PCR amplification; therefore, it is a reliable and cost-saving diagnostic method for evaluating patients infected with herpesvirus with neurological disorders.

Detection of extensively drug-resistant and hypervirulent Klebsiella pneumoniae ST15, ST147, ST377 and ST442 in Iran.

In this study, we focused on the emergence of extensively drug-resistant (XDR), pandrug-resistant (PDR), and hypervirulent Klebsiella pneumoniae (hvKP) in Iran. During 2018 to 2020 a total of 52 K. pneumoniae isolates were collected from different clinical specimens. The hvKP isolates were identified by PCR amplification of virulence and capsular serotype-specific genes. Hypermucoviscous K. pneumoniae (hmKP) were identified by string test. Carbapenem-resistant hvKP (CR-hvKP), multidrug-resistant hvKP (MDR-hvKP), extensively drug-resistant hvKP (XDR-hvKP), and pandrug-resistant hvKP (PDR-hvKP) were determined by disc diffusion method, Carba-NP test and PCR method. XDR-hvKP isolates were typed by multilocus sequence typing (MLST). Among all K. pneumoniae isolates 14 (26.9%) were identified as hvKP and 78.6% (11/14) of them were hmKP however, none of the classic K. pneumoniae (cKP) isolates were hmKP. The predominant capsular serotype of hvKP was K2 (42.85%) followed by K1 (35.71%). The prevalence of MDR-hvKP, XDR-hvKP and PDR-hvKP isolates were 6 (42.9%), 5 (35.7%) and 1 (7.1%), respectively. ESBL production was found in 85.7% of hvKP isolates and most of them carried bla TEM gene (78.6%) and 6 isolates (42.9%) were CR-hvKP. Among hvKP isolates, 1 (7.1%), 2 (14.3%), 3 (21.4%), 8 (28.6%), and 11 (78.6%) carried bla NDM-6, bla OXA-48, bla CTX-M, bla SHV, and bla TEM genes, respectively. According to MLST analysis, 2, 1, 1, and 1 XDR-hvKP isolates belonged to ST15, ST377, ST442, and ST147, respectively. The occurrence of such isolates is deeply concerning due to the combination of hypervirulence and extensively drug-resistance or pandrug-resistance.

Detection of Enterovirus, Herpes Simplex, Varicella Zoster, Epstein-Barr and Cytomegalovirus in cerebrospinal fluid in meningitis patients in Iran.

BACKGROUND: Despite medical advances, central nervous system (CNS) diseases put a pressure on the health care system. A number of risk factors, especially infectious agents can accelerate the progression of meningitis. As viruses probably account for most cases of meningitis, the diagnosis of them can reduce antibiotic prescriptions. Among various types of infectious diseases, the relationship between two important virus families, including Picornaviridae and Herpesviridae, and meningitis has attracted attraction. METHODS: In this study, one hundred and two samples were collected from patients who experienced symptoms, such as the loss of consciousness, seizures, muscle weakness, fever, headache, rash, and severe dementia, between November 2018 and September 2019. After RNA and DNA extraction, the prevalence of Enterovirus (EV), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), Herpes simplex virus type 1 (HSV-1), Herpes simplex virus type 2 (HSV-2), and Varicella zoster virus (VZV) was evaluated using PCR, multiplex PCR, and nested PCR. RESULTS: Results indicated that there were two VZV DNA-positive specimens, while six and five samples were infected with HSV-1 and EBV, respectively. CONCLUSION: We reported that the prevalence of EBV, HSV-1, and VZV in patients, suffering from meningitis cannot be ignored; however, further investigation is needed.

The evaluation of Human papilloma virus and human herpes viruses (EBV, CMV, VZV HSV-1 and HSV-2) in semen samples.

There are a number of risk factors, especially viral diseases, which can lead to infertility. Among the various viral infections, much attention has been given to the role of the Papillomaviridae and Herpesviridae. After collecting 82 semen samples (37 teratospermia, 2 asthenozoospermia, 2 oligoasthenospermia, 1 oligospermia, 6 asthenoteratospermia and 34 normal semen samples), and washing them, the DNA from both freshly ejaculated spermatozoon and washed spermatozoa was extracted. Subsequently, the prevalence of EBV, CMV, HSV-1, HSV-2, VZV and HPV was evaluated using Multiplex PCR and Nested PCR. In this study, 1 normal and 5 abnormal semen samples were infected with HSV-1 (1 normal, 4 teratospermia and 1 oligoasthenospermia). In addition, there were 2 VZV-positive samples (both were teratozoospermia). Nested PCR indicated that 1 asthenozoospermia, 1 asthenoteratospermia, 3 teratospermia and 4 normal samples were HPV positive (including 8 HPV-18 and 1 HPV-33). Among 9 HPV-positive subjects, 3 samples were negative after washing the infected samples. The prevalence of EBV, CMV, VZV, HSV-1 and HSV-2 remained unchanged prior to and after washing. Maybe sperm washing can be useful to eliminate HPV infection from semen samples, but further investigation is required because of the small number of samples.

Detection of human papillomavirus genotypes, herpes simplex, varicella zoster and cytomegalovirus in breast cancer patients.

BACKGROUND: The role of viruses as a cause of breast cancer (BC) has been significantly investigated in recent years. Human papillomavirus (HPV) has been detected in invasive breast carcinomas, while most studies have only focused on the detection of viral DNA, we aimed to examine the prevalence and genotypes of HPV among Iranian BC patients. We also examined the presence of herpes simplex-1 (HSV-1), herpes simplex-2 (HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV) in these samples. METHODS: We collected and analyzed 70 Formalin-Fixed Paraffin-Embedded (FFPE) blocks including 59 BC samples, and 11 benign breast lesions as control from Iranian patients using nested PCR. Real-time PCR utilized as a confirming test to nested PCR findings. Genotyping of HPV positive samples was performed, the samples were also subjected to a multiplex PCR to detect HSV-1, HSV-2, VZV, and CMV in BC. RESULTS: Papillomavirus DNA was present in 7 of 59 BC samples (11.8%); while none was detected in control samples. The most prevalent type was HPV18, followed by HPV 6. All HPV positive patients had high tumor grades (II/ III) with a histologic diagnosis of ductal carcinoma. The patient age range was 33 to 73 years with a median of 51 years. Most of HPV positive patients had low levels of education. HPV16 was not detected. Also, 5 of 59 BC specimens (8.47%), were positive for HSV-1. But none of the samples were positive for HSV-2, VZV, and CMV. CONCLUSIONS: Our results suggest a carcinogenesis role for High-risk HPV (HPV18) in breast tumors. Our findings of HSV-1 and low-risk HPV (HPV6) in BCs may propose a cancer-causing role for them. Further large-scale studies are warranted to assess the significance of our findings.

Proliferative Effect of FadA Recombinant Protein from Fusobacterium nucleatum on SW480 Colorectal Cancer Cell Line.

BACKGROUND AND AIM: Colorectal Cancer (CRC) is one of the most frequent cancers diagnosed in both men and women worldwide. Fusobacterium nucleatum adhesin A (FadA) has an important potential factor in the development or progression of CRC. The aim of the present study was to evaluate the proliferative effect of recombinant FadA on SW480 colorectal cancer cell line. MATERIALS AND METHODS: The recombinant pET21(b)-fadA plasmid was synthesized and transformed into competent E.coli DH5α. In the next step, induction and expression of recombinant FadA were carried out in E. coli BL21 (DE3) competent cells. Expression and purification of protein were successfully done and it was analyzed and confirmed by SDS-PAGE and western blotting. The proliferative effect of purified FadA on SW480 CRC cell line was evaluated using MTT assay and cell counting methods. RESULTS: Visualization of the specific band isolated from the linear plasmid on the agarose gel confirmed the presence of the desired gene. After electrophoresis and Coomassie blue staining, the protein of interest with an approximate molecular weight of 13KDa was detected. The MTT assay, similar to cell counting methods, revealed that FadA dose and time-dependently promoted SW480 cell growth and proliferation in 24, 48 and 72 hours. CONCLUSION: The results showed that FadA stimulates proliferation of SW480 colorectal cancer cell line with a dose and time-dependent manner.

The role of viruses in adenocarcinoma development.

Cancer is a leading public health issue that accounts for million deaths around the world every year. Human cancers contain over 100 types, which are categorized into different groups. Adenocarcinoma is one of those categories of cancer that begins from the glans and involves various tissues such as lung, esophagus, pancreas, prostate and colorectal. A range of risk factors has been identified for the development and progression of adenocarcinomas. One of these risk factors are viruses that serves special mechanisms to affect important host cell factors and tumorigenic pathways, contributing in development and promotion of adenocarcinomas. Here, we summarized the main viruses and their mechanisms implicated in the course of various adenocarcinomas development.

In silico analysis of a chimeric fusion protein as a new vaccine candidate against Clostridium perfringens type A and Clostridium septicum alpha toxins.

In silico analysis is the most important approach to understand protein structure and functions, and the most important problem for designing and producing a fusion construct is producing large amounts of functional protein. Clostridium perfringens type A and Clostridium septicum produce alpha (plc) and alpha toxins respectively. C. perfringens can cause gas gangrene and gastrointestinal diseases. C. septicum can cause traumatic and non-traumatic gas gangrene. The aim of current research was in silico analysis of a chimeric fusion protein against C. perfringens type A and C. septicum alpha toxins. Firstly, the chimeric fusion gene was designed according to nucleotide sequences of C. perfringens type A alpha (KY584046.1) and C. septicum alpha (JN793989.2) toxin genes and then its fusion protein is constructed by amino acid sequences of C. perfringens type A and C. septicum alpha toxins. Secondly, online software was used to determine prediction of secondary and tertiary structures and physicochemical characteristics of the fusion protein. Finally, the validation of the fusion protein was confirmed by Rampage and proSA program. The designed fusion protein has 777 amino acids in length. TASSER server and physicochemical parameters are showed: C-score = - 2.68 and molecular weight = 87.9 KD respectively. Rampage and proSA software revealed the fusion protein is valid. Deposited accession number for the sequence of the fusion gene in the GenBank is MK908396. The designed fusion protein is valid and functional. Thus, the fusion gene could be used for clone and expression in a proper prokaryotic cell and also as a recombinant vaccine candidate.

P16INK4A Immunohistochemistry as a Gold Standard for Cervical Cancer and Precursor Lesions Screening.

BACKGROUND: High-risk (HR) Human papillomaviruses (HPVs) are known as the main factors implicated in the pathogenesis of cervical preinvasive and invasive lesions. Therefore, the presence or absence of HR-HPV can be followed for the prognosis of low-grade and high-grade squamous intraepithelial lesions. Since the overexpression of p16INK4a protein depends on the presence of transcriptionally-active HPV, and due to its availability and simple interpretation, it may be considered as a proper marker to diagnose cervical cancer. METHODS: An immunohistochemical analysis of p16INK4a was performed in 72 cervical tissue specimens at Imam Khomeini Complex Hospital (Tehran, Iran) from 2016 to 2018. The performance parameters were calculated and compared using receiving operating characteristics curve (ROC) details. RESULTS: p16INK4a is significantly up-regulated in the cervical cancer samples in comparison with that in normal samples. Moreover, the ROC data showed the potential ability of p16INK4a under determined conditions as a diagnostic marker for CIN 2-3 staging and invasive cervical cancer. The molecular typing disclosed the attendance of HPV DNA in 44.4% of cases (32/72) with a predominance of HPV type 16. CONCLUSION: The molecular biomarker p16INK4a can be a good candidate for the early diagnosis and prognosis of cervical cancer in HPV-infected patients. Considering the increase in the expression level of p16INK4a in cancer and precancer tissues, p16INK4a may be used for early detection of cervical cancer.

Cyclin-dependent kinases and CDK inhibitors in virus-associated cancers.

The role of several risk factors, such as pollution, consumption of alcohol, age, sex and obesity in cancer progression is undeniable. Human malignancies are mainly characterized by deregulation of cyclin-dependent kinases (CDK) and cyclin inhibitor kinases (CIK) activities. Viruses express some onco-proteins which could interfere with CDK and CIKs function, and induce some signals to replicate their genome into host's cells. By reviewing some studies about the function of CDK and CIKs in cells infected with oncoviruses, such as HPV, HTLV, HERV, EBV, KSHV, HBV and HCV, we reviewed the mechanisms of different onco-proteins which could deregulate the cell cycle proteins.

The roles of programmed death ligand 1 in virus-associated cancers.

Programmed death ligand 1 (PD-L1) is a surface glycoprotein that induces T-cell anergy or apoptosis by binding to PD-1 on activated T and B cells. It is also known as a cluster of differentiation 274 (CD274) or B7 homolog 1 (B7-H1). Suppressing the adaptive arm of the immune system is the critical role of PD-L1.so it prohibits the proliferation of activated T cells and reduces apoptosis in regulatory T cells. When PD-L1 binds to PD-1, it prevents T cells from killing other cells such as cancer cells. Viruses have various strategies to evade from the immune system such as modifying host gene expression or deregulating proteins function. So they can directly or indirectly change the expression of PD-L1. This study proposed to evaluate the effect of viruses on the expression of PD-L1 which leading to uncontrolled cell growth and tumor formation. We have studied serious tumorigenic viruses, including Human Papillomaviruses (HPV), Epstein-Barr viruses (EBV), Human T-cell leukemia viruses type 1 (HTLV-1), Hepatitis B viruses (HBV) and Hepatitis C viruses (HCV). So we surveyed the correlation between the presence of viruses and expression of PD-L1. Most studies showed the PD-L1 overexpression due to viral functions; however, further studies are needed to better understand the role of the PD-1/PD-L1 pathway in virus-associated cancers as a candidate of anti- PD-L1 therapy.

Evaluating the expression level of miR-9-5p and miR-192-5p in gastrointestinal cancer: introducing novel screening biomarkers for patients.

OBJECTIVE: It has been indicated that there is a tight association between cancer and different factors, such as environment and genetics, including aberrantly expressed microRNAs. The crucial role of microRNAs in the regulation of diverse signaling pathways in gastrointestinal cancer has been established in several studies. In this study, we aimed to evaluate the expression of microRNA-9 and -192 in colon and gastric cancers. After extracting the RNA from tissues and serum samples of patients, suffering from colon and gastric cancer, cDNA was synthesized. Then by performing quantitative real-time PCR, we evaluated the expression level of miR-9-5p and miR-192-5p in collected samples. RESULTS: Unlike to colon cancer in which the expression level of miR-9-5p remained unchanged, the relative expression of this miRNA decreased remarkably in gastric cancer (with P value < 0.05), in comparison with normal adjacent tissues. In agreement with this finding, we also found that the expression level of miR-192-5p was decreased in gastric cancer tissues, compared to normal gastric tissue. Given the reduction in the expression level of miR-9-5p and miR-192-5p in gastric cancer, it could be postulated to consider these miRNAs as promising diagnostic biomarkers.