A Cell-Based Method for Identification of Chemotherapy Resistance Cancer Genes

Author(s):  
Raffaele Hellweg ◽  
Ashley Mooneyham ◽  
Martina Bazzaro
2021 ◽  
Author(s):  
Moataz Dowaidar

Autophagy is a double-edged sword in cancer, and numerous aspects should be taken into account before deciding on the most effective strategy to target the process. The fact that several clinical studies are now ongoing does not mean that the patient group that may benefit from autophagy-targeting medicines has been identified. Autophagy inhibitors that are more potent and specialized, as well as autophagy indicators, are also desperately required. The fact that these inhibitors only work against tumors that rely on autophagy for survival (RAS mutants) makes it difficult to distinguish them from tumors that continue to develop even when autophagy is absent. Furthermore, mutations such as BRAF have been shown to make tumors more susceptible to autophagy suppression, suggesting that targeting such tumours may be a viable strategy for overcoming their chemotherapy resistance. In the meantime, we are unable to identify if autophagy regulation works in vivo or whether it selectively targets a disease while inflicting injury to other healthy organs and tissues. A cell-type-specific impact appears to be observed with such therapy. As a result, it is just as important to consider the differences between tumors that originate in different organs as it is to consider the signaling pathways that are similar across them. For a therapy or cure to be effective, the proposed intervention must be tailored to the specific needs of each patient.Over the last several years, a growing amount of data has implicated autophagy in a variety of disorders, including cancer. In normal cells, this catabolic process is also required for cell survival and homeostasis. Despite the fact that medications targeting intermediates in the autophagy signaling pathway are being created and evaluated at both the preclinical and clinical levels, given the complicated function of autophagy in cancer, we still have a long way to go in terms of establishing an effective therapeutic approach. This article discusses current tactics for exploiting cancer cells' autophagy dependency, as well as obstacles in the area. We believe that the unanswered concerns raised in this work will stimulate researchers to investigate previously unknown connections between autophagy and other signaling pathways, which might lead to the development of novel, highly specialized autophagy therapies.


2020 ◽  
Vol 7 (1) ◽  
pp. 25-43
Author(s):  
Hemantkumar Patadia ◽  
Ankita Priyadarshini ◽  
Jay Ranade ◽  
Ajit Gangawane

Background: Breast Cancer is a recurrent problem across the world. According to a report, breast cancer has the second highest mortality rate in women globally. Despite having an advanced degree of chemotherapy, resistance is developed against the therapies. Studies showed that anthracyclins like doxorubicin used in the treatment of breast cancer are found to develop resistance, which is not easy to identify. Mutations in the tumor suppressor gene P53 are associated with the primary resistance to doxorubicin and thus inducing an early relapse of breast tumors. Resistance against Doxorubicin is not identifiable easily. Development of resistance and metastasis of tumors are the two processes that cannot be separated from each other. It is widely known that endothelium has a major role in controlling metastasis and tumor cell invasion. Endothelial cells express different adhesion molecules during recruitment of leukocytes in localized area, which is called leukocyte extravasation or diapedesis, or leukocyte trans endothelial migration (LEM). LEM (leukocyte trans endothelial migration) plays crucial role in the inflammation of breast cancer tissues. Objective: Predicting the role of deregulation of claudins in leukocyte trans endothelial migration in breast cancer metastasis and resistance. Method: The breast cancer proteomic metadata was collected and compared among the common candidates. The enrichment analysis of those common candidates was performed using a network analyst. Result: The analysis of breast cancer genes obtained from dbDEPC showed probable involvement of 4 candidate genes belonging to the claudin family. Claudins are responsible for the migration of an increased amount of leukocytes in the breast tumor region, which increases the inflammation and may contribute to worsening the disease progression. Conclusion: We believe these candidates also contribute in the development of resistance to chemotherapy.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 21144-21144
Author(s):  
U. Vogt ◽  
D. Kemming ◽  
B. Brandt ◽  
U. Bosse ◽  
U. Bonk ◽  
...  

21144 Background: More than 28000 curated human genes can be analyzed semi-quantitatively using a chemiluminescent detection technology and 60mer oligonucleotides on a Human Genome Survey Microarray (HGSM, Applied Biosytems). Methods: HGSM expression profiling was performed on biopsy samplesfrom a setting of patients under neoadjuvant treatment. The protocol for a phase II study was elaborated for the treatment of breast cancer patients suffering from a primary tumor > 1,5 cm or inflammatory breast cancer with Docetaxel / Epirubicin/Cyclophosphamide (TEC) prior to surgical treatment. The study was approved by the local ethical committee and 80 patients will be included into the study after written informed consent. 40 patients have been already included in the ongoing study. In this prospective study a biopsy from the tumor is taken before chemotherapy. Therefore, success of treatment is detectable directly at the operated residual tumor. Our results demonstrate a low rate of false-positives (1.2%), a high specificity and quantification accuracy of HGSM system. Comparison of data from HGSM and RT-PCR obtained on mRNA from fresh frozen tissue resulted a Pearson-correlation of 0.92 to 0.63 for the breast cancer genes. Results: Tumour response (pCR, pPR) of more than 70 % can be achieved using neoadjuvant TEC- regimen. 25 % of pCR in this study is comparable with data of other published neoadjuvant trails. First expression profiling results are obtainable showing that a subset of 148 genes indicates patients with complete remission (pCR, no detectable tumor at end of chemotherapy), partial remission (pPR) and progressive disease (pPD). Remarkable, that the expression profile clearly separated pCR and pPD tumors whereas pPR tumors presented with a closer relationship to pPD tumors than to pCR tumors but displayed small specific subprofiles. A comparable separation of the groups could not achieved by established tumor markers, e.g. ER, PgR, HER2, uPA etc. which are measured simultaneously on the HGSM. Conclusions: HGSM expression profiling is promising to have the potential to figure out genes that are related to cancer progression and chemotherapy resistance, especially in PST. No significant financial relationships to disclose.


2022 ◽  
Vol 12 (1) ◽  
pp. 98
Author(s):  
Grace S. Shieh

Two genes are said to have synthetic lethal (SL) interactions if the simultaneous mutations in a cell lead to lethality, but each individual mutation does not. Targeting SL partners of mutated cancer genes can kill cancer cells but leave normal cells intact. The applicability of translating this concept into clinics has been demonstrated by three drugs that have been approved by the FDA to target PARP for tumors bearing mutations in BRCA1/2. This article reviews applications of the SL concept to translational cancer medicine over the past five years. Topics are (1) exploiting the SL concept for drug combinations to circumvent tumor resistance, (2) using synthetic lethality to identify prognostic and predictive biomarkers, (3) applying SL interactions to stratify patients for targeted and immunotherapy, and (4) discussions on challenges and future directions.


Author(s):  
M. Arif Hayat

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.


Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


Author(s):  
G. Rowden ◽  
M. G. Lewis ◽  
T. M. Phillips

Langerhans cells of mammalian stratified squamous epithelial have proven to be an enigma since their discovery in 1868. These dendritic suprabasal cells have been considered as related to melanocytes either as effete cells, or as post divisional products. Although grafting experiments seemed to demonstrate the independence of the cell types, much confusion still exists. The presence in the epidermis of a cell type with morphological features seemingly shared by melanocytes and Langerhans cells has been especially troublesome. This so called "indeterminate", or " -dendritic cell" lacks both Langerhans cells granules and melanosomes, yet it is clearly not a keratinocyte. Suggestions have been made that it is related to either Langerhans cells or melanocyte. Recent studies have unequivocally demonstrated that Langerhans cells are independent cells with immune function. They display Fc and C3 receptors on their surface as well as la (immune region associated) antigens.


Author(s):  
Hannah R. Brown ◽  
Tammy L. Donato ◽  
Halldor Thormar

Measles virus specific immunoglobulin G (IgG) has been found in the brains of patients with subacute sclerosing panencephalitis (SSPE), a slowly progressing disease of the central nervous system (CNS) in children. IgG/albumin ratios indicate that the antibodies are synthesized within the CNS. Using the ferret as an animal model to study the disease, we have been attempting to localize the Ig's in the brains of animals inoculated with a cell associated strain of SSPE. In an earlier report, preliminary results using Protein A conjugated to horseradish peroxidase (PrAPx) (Dynatech Diagnostics Inc., South Windham, ME.) to detect antibodies revealed the presence of immunoglobulin mainly in antibody-producing plasma cells in inflammatory lesions and not in infected brain cells.In the present experiment we studied the brain of an SSPE ferret with neutralizing antibody titers of 1:1024 in serum and 1:512 in CSF at time of sacrifice 7 months after i.c. inoculation with SSPE measles virus-infected cells. The animal was perfused with saline and portions of the brain and spinal cord were immersed in periodate-lysine-paraformaldehyde (P-L-P) fixative. The ferret was not perfused with fixative because parts of the brain were used for virus isolation.


Author(s):  
N. Savage ◽  
A. Hackett

A cell line, UC1-B, which was derived from Balb/3T3 cells, maintains the same morphological characteristics of the non-transformed parental culture, and shows no evidence of spontaneous virus production. Survey by electron microscopy shows that the cell line consists of spindle-shaped cells with no unusual features and no endogenous virus particles.UC1-B cells respond to Moloney leukemia virus (MLV) infection by a change in morphology and growth pattern which is typical of cells transformed by sarcoma virus. Electron microscopy shows that the cells are now variable in shape (rounded, rhomboid, and spindle), and each cell type has some microvilli. Virtually all (90%) of the cells show virus particles developing at the cell surface and within the cytoplasm. Maturing viruses, typical of the oncogenic viruses, are found along with atypical tubular forms in the same cell.


Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).


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