Indirect Effects of COVID on Oncology Patients.

The interaction of coronavirus disease-2019 (COVID-19) and chemotherapy may result in worse outcomes. However, there may be more indirect effects of COVID. We report 3 cases in which treatment was delayed because of COVID-related inability or reluctance to travel. Oncology programs should consider such indirect effects when devising treatments.

HPV infections in retinoblastoma: a systematic review.

BACKGROUND: Retinoblastoma is the most common primary intraocular malignancy in children less than 4 years. Retinoblastoma (RB) contains about 3%-5% of all childhood cancers. Recent studies demonstrated that interacting between RB tumor suppressor and oncoproteins of DNA tumor viruses such as human papillomavirus (HPV). The objective of the current systematic review study was to present conducted studies in the field of HPV infection and its possible role in retinoblastoma. METHODS: For this systematic review, all relevant original research studies were assessed by searching in electronic databases include PubMed, Embase, Scopus, Google Scholar, and Web of Science by using relevant keywords. The study was designed based on the PRISMA criteria. All publications with English literature and original researches are considered for screening. RESULTS: Conducted search results lead to 4070 studies. The title and abstract screening lead to 11 studies. Data extraction was performed on 8 included studies. The prevalence of the HPV was ranged from 0 to 69%, and HPV genotype 16 and 18 were the most detected types. The most used method for the detection of the viruses was PCR, and the most assessed sample was formalin-fixed, paraffin-embedded tissue blocks. CONCLUSION: The association between HPV and retinoblastoma is still inconsistent. The prevalence of the HPV in RB was ranged from 0 to 69%, which indicates a wide range and highlights the importance of further investigation for more accurate statistical of HPV prevalence in RB. Thus, further worldwide studies of larger sample sizes of cohorts should be investigated to clarify this uncertainty.

Cytomegalovirus disease in a retinoblastoma cohort: The role of preemptive screening.

BACKGROUND: Cytomegalovirus (CMV) disease is underrecognized in children with retinoblastoma. This study investigated rates of CMV infection and disease in this specific population receiving chemotherapy. METHODS: From a cohort of 164 patients with retinoblastoma diagnosed from 2011 to 2018, 107 patients were evaluated for CMV infection determined by antigenemia assay or real-time PCR. Preemptive CMV screening was implemented in 2013. CMV disease was diagnosed by tissue biopsy, culture, or ophthalmic examination. RESULTS: Thirty-seven and 70 patients before and after the screening strategy, respectively, were included. Before screening, 10/37 (27%) were diagnosed with CMV infection during chemotherapy. Among them, 5 (50%) developed CMV disease (hepatitis, pneumonia, and retinitis) and one patient died of CMV pneumonia. During screening, 18/70 (26%) were documented with 36 episodes of CMV infection and 9 patients received 25 preemptive antiviral therapies. Age at chemotherapy tended to be younger in patients with CMV infection, and fewer were seronegative prior to chemotherapy. Patients who started chemotherapy at <12 months of age received preemptive therapies significantly more often than those started at ≥12 months. Two (11%) out of 18 patients with CMV infection developed CMV retinitis and colitis, and there were no fatal cases. Preemptive therapy along with active CMV screening significantly reduced the risk of developing CMV disease, from 14% to 2.9% (P = 0.047). CONCLUSIONS: Children with retinoblastoma can experience significant morbidity and even mortality from CMV infection during chemotherapy in Korea. Preemptive screening and appropriate antiviral therapy can reduce the development of CMV disease and subsequent mortality.

HPV-16 Detected in One-Fourth Eyes With Retinoblastoma: A Prospective Case-control Study From North India.

The incidence of nonfamilial retinoblastoma (RB) is believed to be higher in developing countries. The reports on association of human papillomavirus (HPV) with RB are limited and contradictory. The aim was to investigate the prevalence of HPV in RB tumor tissue. In the prospective study, consecutive eyes enucleated for RB from patients lacking a family history of RB were enrolled as cases over a 3-year period. Controls included donor eyes obtained from the eye bank. Normal retinal tissue from the donor eyes and tumor tissue from eyes with RB was subjected to DNA isolation. Polymerase chain reaction followed by dot-blot hybridization was performed to detect 21 HPV genotypes. The study cohort included 39 RB and 42 normal retinal tissues. A positive result for HPV-polymerase chain reaction was obtained in 10 (25.6%) tumor tissues and none of the control eyes. HPV-16 was the only subtype detected. Socioeconomic status (P=0.58) or maternal age (P=0.58) was not associated with presence of HPV. All HPV-positive patients had undergone a vaginal delivery (P=0.60). HPV-16 was detected in one-fourth cases of nonfamilial RB. None of the control cases (donor eyes) tested positive. Implication of the presence of HPV in RB tissue and role in carcinogenesis needs further elucidation.

Evidence for the presence of high risk human papillomavirus in retinoblastoma tissue from nonfamilial retinoblastoma in developing countries.

BACKGROUND: The prevalence of human papillomavirus (HPV) infection in India is high. HPV infection is known to cause cervical cancer and has also been implicated in the pathogenesis of retinoblastoma (RB), a common intraocular malignant tumor of childhood which can be familial or sporadic. Despite the high incidence of RB in India, its familial form is rare. Hence this study was undertaken to investigate whether high-risk HPV types 16 and 18 are involved in the development of RB. METHODS: Formalin fixed paraffin embedded RB tissues (n = 76) including prospective cases with corresponding maternal cervical smears (n = 10) were analyzed for the presence of HPV DNA sequences. Expression of the cell cycle regulatory proteins viz; p105, p107, p30, p16, E2F-1, E2F-4, and MiB-1 was studied by immunohistochemistry (IHC) (n = 34). RESULTS: A total of 53 out of 76 (69.7%) cases were positive for HPV, of these 3 cases were positive for HPV-16, 23 for HPV-18, and 27 for both HPV-16 and -18. Of the prospective cases (n = 10) studied, five cases along with the corresponding maternal cervical cytology smear had identical HPV status. HPV-16 positive tumors were classified as well differentiated (P = 0.013). Nuclear expression of pRB2/p130 showed significant association with HPV-16 infection (P = 0.04) or dual infection of HPV-16/-18 (P = 0.02). CONCLUSIONS: Our study lends support to the hypothesis that infection of HPV-16/-18 may play an important role in the development of nonfamilial form of RB in children in India.

Low prevalence of HPV in Brazilian children with retinoblastoma.

Retinoblastoma is the most frequent intra-ocular malignant tumor of the childhood, occurring in 1 of 18,000-30,000 live births. Little is known about the causes of sporadic retinoblastoma and only a few authors have investigated the etiologic role of human papillomavirus (HPV), with controversial results. Formalin-fixed, paraffin-embedded tissue blocks containing retinoblastoma were retrieved from the archives of the Department of Pathology at Hospital A C Camargo, São Paulo, Brazil. All patients were treated with enucleation (21 children had both eyes enucleated). Retinoblastoma and, when possible, normal retina of each specimen, were micro-dissected under direct light microscopic visualization by using a PixCell II Laser Capture Micro-dissection System. The DNA quality was evaluated by polymerase chain reaction (PCR) amplification of 110 base pairs fragment of the human ß-globin gene using primers PCO3+/PCO4+. All globin positive specimens were analyzed by PCR for the presence of HPV DNA using consensus primers GP5+/GP6+. A total of 154 specimens were evaluated. Forty-four patients also had normal retinal specimens available for analysis of DNA HPV. The DNA HPV prevalence among all tumor specimens was 4.6% (95% CI 2.0; 8.8) (7 positive specimens/153 adequate specimens). Among normal retinal specimens, the DNA HPV prevalence was 9.1% (95% CI 2.9; 20.5) (4 positive specimens/44 specimens). There was no statistically significant difference between these rates (P = 0.318). Excluding any experimental failure, our results indicate a low prevalence of HPV DNA in retinoblastomas. We were therefore unable to conclude about the association between these oncogenic viruses and this rare pediatric neoplasm.

Oncolytic adenovirus delivering herpes simplex virus thymidine kinase suicide gene reduces the growth of human retinoblastoma in an in vivo mouse model.

Oncolytic conditionally replicating adenoviruses (CRAd) can exclusively replicate in and lyse tumor cells and are therefore promising tools in cancer therapy. In this study, we combined the oncolytic potential of a CRAd with its ability to deliver a suicide gene (herpes simplex virus thymidine kinase suicide gene, HSVtk) in order to further enhance tumor cell killing in a human retinoblastoma (RB) mouse model. We could demonstrate that CRAd driven by the human telomerase reverse transcriptase (hTERT) promoter and armed with the HSV thymidine kinase suicide gene/ganciclovir (HSVtk/GCV) could very effectively reduce growth of human RB in an orthotopic nude mouse model. These findings suggest that hTERT promoter-driven CRAd in combination with HSVtk/GCV gene therapy could be a promising new approach for the treatment of RB. In addition, we found that hTERT promoter-driven CRAd replication occurred exclusively in human RB cells but not in primary human retinal pigment epithelial cells (hRPE), indicating that application of hTERT promoter-driven CRAd for the treatment of RB would be safe.

Detection of human papillomavirus DNA in retinoblastoma samples: a preliminary study.

Recent studies have shown the presence of human papillomavirus (HPV) genome in retinoblastoma (RB) tumor samples. There is no information on the HPV status in the RB tumors of Indian patients. We studied the presence of HPV genome in RB tumor samples from patients with unilateral tumor. Forty-four fresh RB tumor samples and 30 non-neoplastic donor retinas were analyzed for the presence of HPV 16 and 18 genome by nested and seminested polymerase chain reaction. Tumor tissue sections were also used to assess the expression of the retinoblastoma (Rb) protein. All 30 control tissues were negative for HPV genome. Among the 44 tumor samples, there were 23 tumors with invasion of optic nerve/choroid and 21 tumors with no invasion. HPV DNA was present in 21/44 (47%) RB tumors. Among 21 unilateral RB tumors that were positive for HPV DNA, HPV 16 was detected in 12/21 (57%) tumors. However, HPV 18 was negative in all the tumors. Rb protein was absent in 16 (71%) of 21 tumors that had HPV DNA. However, Rb was also absent in 20 (86%) of 23 tumors that were HPV negative. Children younger than 18 months old were significantly associated with the presence of HPV DNA compared with children above 24 months old (P<0.014). Our study shows the presence of HPV and HPV 16 in a subset of RB tumor samples. However, further studies are in progress to know the role played by HPV in RB.

Acetylcholinesterase and HHV-8 in squamous cell carcinoma and retinoblastoma.

Acetylcholinesterase (AChE) and human herpesvirus type 8 (HHV-8) antigens were studied in tissue sections from 56 squamous cell carcinomas (SCC) and five retinoblastomas (Rb). Approximately 62.5% of SCC and 80% of Rb showed positive staining for AChE. AChE staining in tumors was much higher than in normal control tissue. However, only 21.4% of SCC and 60% of Rb contained HHV-8 antigens. Of the 56 SCC, 17.9% were positive for both AChE and HHV-8 antigens, whereas 60% Rb were positive for both markers. The co-existence of AChE and HHV-8 antigens may play a role in the development of SCC and Rb. A possible mechanism for the development of these tumors is discussed.

Human papillomavirus in ocular malignant tumours: a study from a tertiary eye care centre in North India.

OBJECTIVE: The present study aims to detect the presence of human papillomavirus (HPV) in ocular malignant tumours, including retinoblastoma, eyelid squamous cell carcinoma (SCC), and sebaceous gland carcinoma (SGC), in the North Indian population. DESIGN: Prospective observational non randomized study. PARTICIPANTS: In this study, 142 prospective cases of ocular malignant tumours (retinoblastoma, SGC, and SCC) were included. METHODS: HPV was detected by multiplex PCR using PGMY09/11 primers in 142 patients with ocular malignancies. This was followed by genotyping using linear array (reverse hybridization). RESULTS: Of the 142 tumours studied, 72 were retinoblastoma, 30 SGC, and 40 SCC. The HPV genome was detected in 2.8% (4 of 142) of cases by multiplex PCR; all positive cases (4 of 40) were SCC. Genotyping revealed that all positives belonged to the high-risk HPV16 genotype. HPV-positive SCC patients had better disease-free survival. Retinoblastoma and SGC cases were negative for HPV. CONCLUSIONS: Low prevalence of HPV in ocular malignancies was observed in this study. The HPV genome was detected only in ocular squamous cell carcinoma cases and these patients were associated with better prognosis. HPV may not have a role in retinoblastoma and SGC in the North Indian population.

HSV­TK/GCV can induce cytotoxicity of retinoblastoma cells through autophagy inhibition by activating MAPK/ERK.

Retinoblastoma is an severe ophthalmic disease and the most common type intraocular malignant tumor, particularly in infants. Currently, few drugs and therapies are available. Gene therapy has been considered to be a potential treatment to cure cancer effectively and Herpes simplex virus type 1 thymidine kinase/ganciclovir (HSV­TK/GCV) is one type of suicide gene therapy that has been extensively studied. Numerous in vitro and in vivo studied have shown that this system can kill tumor cells, including liver and lung cancer cells. GCV is used as an antiviral drug, and the thymidine kinase, HSV­TK can phosphorylate GCV to GCV­TP, a competitive inhibitor of DNA synthesis, instead of guanine­5'­triphosphate in the process of DNA synthesis. This process prevents DNA chain elongation causing cell death via apoptosis. However, the toxic effects of HSV­TK/GCV on retinoblastoma cells remain unknown, and the molecular mechanisms of its therapeutic effects have not been fully elucidated. Our results suggest that HSV­TK/GCV can significantly cause the death of retinoblastoma cell lines, HXO­RB44 and Y79. Further studies have reported that this cell death is induced by the inhibition of autophagy by activating the MAPK/ERK (mitogen­activated protein kinase/ERK) signaling pathway. The mTOR inhibitor Torin1 can partially block the toxic effects of HSV­TK/GCV on HXO­RB44 cells. The above results demonstrate that the mechanism undertaken by HSV­TK/GCV to exhibit therapeutic effects mechanism may inhibit autophagy by activating MAPK/ERK. The findings of the present study may provide novel insight for the exploration of HSV­TK/GCV in the treatment of retinoblastoma.

Loss of 10p material in a child with human papillomavirus-positive disseminated bilateral retinoblastoma.

Retinoblastoma (RB) is a malignant childhood tumor that results from loss or inactivation of both alleles of the RB1 gene. Human papillomavirus (HPV) DNA sequences have been found in RB tissue, suggesting a role of the viral infection with RB. We here describe a child with disseminated bilateral RB without familial history, who displayed a loss of material from 10p. Fluorescence in situ hybridization studies showed a somatic loss of both alleles of the RB1 gene. Moreover, sequences for HPV-6a were detected on DNA extracted from eye tumor tissue and from nonstimulated peripheral blood leukocyte cultures. The eye tumor tissue was also positive for HPV L1 viral proteins. Repeated loss of the short arm of chromosome 10 in HPV-transfected keratinocytes has been reported. Loss of heterozygosity in 10p14 approximately p15 is also frequent in cervical cancers. Therefore, it seems probable that the abnormalities on 10p detected in the present case are related to the HPV infection. Thus, HPV could be a cofactor in the progression of RB by promoting nonrandom additional mutations.

Presence of human papilloma virus in tumor tissue from children with retinoblastoma: an alternative mechanism for tumor development.

Epidemiological studies have shown that the use of barrier methods of contraception is associated with a decreased incidence of papilloma virus infection and reduced risk of having a child with retinoblastoma. Thirty-nine primary retinoblastomas were analyzed for the presence of papilloma virus sequences. Tumor tissue sections were also used to assess the expression of the retinoblastoma protein and proliferative index. Papilloma sequences were detected in 14 of 39 (36%) tumors. Tumors in which viral sequences were detected were associated with a lower proliferative index (68% versus 78%; P = 0.015). Children with tumors containing viral sequences had a lower risk of extraocular disease (odds ratio, 9.0; 95% confidence interval, 1.6-49; P = 0.008) and a lower birth weight (2.9 versus 3.5 kg; P = 0.030). Based on these data, it is our hypothesis that papilloma viruses may play a role in the development of sporadic retinoblastoma. Detection of papilloma virus sequences and retinoblastoma protein in certain primary lesions suggests an alternative mechanism of tumor development for sporadic retinoblastoma.

Chapter 9: Role of mucosal human papillomavirus in nongenital cancers.

Established associations between human papillomavirus (HPV) and lower genital tract cancers provide a framework from which to evaluate a possible pathogenic role for the virus in cancers at nongenital sites. Proposed associations must fit coherently within the context of our current knowledge of the epidemiology and biology of HPV. In this article, insights obtained from studies of the etiologic link between mucosal-type HPV infection and four specific human cancers are described briefly. Specific characteristics, shared among cancers caused by HPV, are then used by extrapolation to discuss possible associations between certain other nongenital cancers and mucosal HPV infections in a manner intended to supplement, and in no way to supplant, the classic Hill criteria for causal inference.

Oncolytic viruses: programmable tumour hunters.

Despite significant improvements in early detection and refinements of therapeutic protocols over the last several decades, cancer remains one of the leading causes of death in North America. In particular, treatment of metastatic cancers is a highly desirable and yet still elusive goal of the oncologist. One strategy which holds promise is the use of self replicating viral strains with the ability to specifically kill tumour but not normal cells. These so-called "oncolytic viruses" are in general, attenuated for growth in normal cells but are able to exploit tumour specific, genetic defects to gain a growth advantage. In this review, we will discuss the virus:host cell interactions which help form the niche occupied by oncolytic viruses. The current and potential clinical applications/limitations will be discussed for oncolytic viruses from the herpesvirus, adenoviruses, picornavirus, rhabdovirus, and paramyxovirus families.

An experimental application of gene therapy for human retinoblastoma.

PURPOSE: The purpose was to determine the potential of gene therapy for retinoblastoma using transfer of the herpes simplex virus thymidine kinase (HSV-TK) gene into retinoblastoma cells (Y79 cell line). METHODS: A retrovirus-packaging cell line PA317 was electroporated with a retroviral vector plasmid bearing HSV-TK and neomycin-resistance genes to produce a PA317-TK cell line releasing a replication-defective vector bearing both genes. Y79 was transduced by exposure to transmissible virus-containing medium from PA317-TK, and new clones of Y79 containing the HSV-TK gene (Y79-TK) were established. Sensitivity to ganciclovir (GCV) and acyclovir (ACV) was investigated in Y79 and Y79-TK and the effect of HSV-TK-positive cells on negative cells ("bystander effect") was determined in vitro. The effect of antitumorigenesis in a nude mouse system was also investigated. RESULTS: There were no differences in the growth pattern or the morphology between Y79 and Y79-TK. Y79-TK was more sensitive to GCV and ACV than was Y79. The cytotoxicity of Y79-TK was dose dependent. An obvious "bystander effect" was present with the addition of GCV. In vivo studies confirmed the ability of GCV to kill Y79-TK. CONCLUSIONS: In this study a model is proposed for the introduction of a drug-sensitivity gene into Y79 and the possibility is raised of treating retinoblastoma with gene therapy. The results suggest that the transfer of the HSV-TK gene into Y79 followed by the administration of GCV could serve as a model for gene therapy for retinoblastoma.

Identification of DNA sequences and viral proteins of 6 human papillomavirus types in retinoblastoma tissue.

PURPOSE: To detect DNA and proteins of human papillomavirus (HPV) in paraffin-embedded retinoblastoma (RB) tissue, to identify the viral types present and to describe a possible association between the presence of HPV and a particular form of RB. MATERIALS AND METHODS: Fifty-one samples from ocular tissues of RB patients and of six controls enucleated for non-neoplastic reasons were obtained and analyzed by Polymerase Chain Reaction (PCR) with consensus primers to detect HPV. Viral type identification was performed by Restriction Fragment Length Polymorphisms (RFLP) analysis. To corroborate the presence of HPV, immunohistochemical analysis with a polyclonal anti-HPV antibody was performed in 10 RB cases and in all controls. RESULTS: Forty-two (82.3%) of the 51 samples were HPV-positive. HPV 6 was detected in 40 cases (95.2%), HPV 33 in 16 (38.1%), HPV 11 in 4 (9.5%) and HPV 31, 35 and 51 each in one case (2.3%). All controls were negative for HPV-DNA. The positive samples were PCR-tested for HPV 16 and 18 using specific primers, and were all negative. For immunohistochemical analysis, 7 out of 10 PCR-positive samples randomly chosen were positive; all six controls were negative. CONCLUSION: No differences in the HPV type distribution were found between the groups formed according to the tumor presentation or to the mode of inheritance.

Evaluation of the antitumor effects of Herpes simplex virus lacking ribonucleotide reductase in a murine retinoblastoma model.

PURPOSE: To determine if an attenuated herpes simplex virus (HSV) lacking the large subunit of ribonucleotide reductase has antitumor effects in a transgenic mouse model of retinoblastoma (LHbetaTAg). METHODS: LHbetaTAg mice were injected ocularly with 1 x 10(6) pfu of the hrR3 virus and tumor sizes were measured 3 weeks later. Replication of the virus in the eye and cultured murine retinoblastoma cells was tested by titration. Distribution of the virus in tumor was measured by X-gal staining. RESULTS: Intraocular injection of mice with hrR3 (n = 24) did not result in a significant reduction in tumor size compared to uninjected (n = 24) or PBS injected controls (n = 16). Neither the hrR3, nor the HSV RE6 mutant, which was previously shown to have antitumor effects in vivo, replicated in cultured murine tumor cells in vitro, compared to wild-type HSV. The hrR3 virus also did not replicate significantly in tumor cells in vivo, compared to normal eye tissue. CONCLUSIONS: These results suggest that mutant HSV lacking ribonucleotide reductase do not display oncolytic activity in the LHbetaTAg mouse and that this model may not be suitable for studying viral oncolysis as a therapy for retinoblastoma.

Mutant herpes simplex virus-mediated suppression of retinoblastoma.

PURPOSE: To test the ability of a mutant herpes simplex virus (HSV) hrR3 to inhibit growth of Y79 human retinoblastoma in vitro and in vivo. METHODS: Cultured Y79 cells were infected with multiplicities of infection (MOI) ranging from 0.004 to 0.1 of hrR3. Surviving cells were counted using trypan blue dye exclusion. Using X-gal staining, expression of the lacZ gene was examined in vitro on day 3 postinfection to evaluate viral replication. Nude mice harboring Y79 tumors subcutaneously received an intraneoplasmic injection of 5 x 10(7) plaque-forming units of hrR3. The tumor sizes were measured weekly. Expression of the lacZ gene was also examined on one week postinfection. RESULTS: There are 31% and 13% cells surviving in cultured Y79 cells infected by hrR3 at an MOI of 0.1 on days 3 and 5 postinfection respectively compared to those of mock-infected cells. Also more than 70% of Y79 cells were stained with X-gal at an MOI of 0.1 which demonstrated active viral replication in vitro. Virus-treated subcutaneous tumors were smaller than control tumors (p<<0.05, Student's t-test) on days 14, 21, and 28 postinfection. Positive X-gal staining was also observed in the tumor nodule which was challenged with this viral vector. CONCLUSIONS: We have demonstrated that hrR3 is capable of inhibiting Y79 tumor growth both in cell culture and in nude mice. These data suggest that gene therapy using this mutant HSV vector can be a new supplementary therapeutic modality for retinoblastoma.