- Written by: Frank
- Category: SMR peptide antagonizes mortalin promoted release of extracellular vesicles and affects mortalin protection from complement-dependent cytotoxicity in breast cancer cells and leukemia cells.
- Published: May 10, 2020
Background: Mortalin/GRP-75/mt-hsp70 is a mitochondrial chaperone protein, discovered in the cytoplasm, endoplasmic reticulum and cytoplasmic vesicles.
It features in many mobile processes similar to mitochondrial biogenesis, intramobile trafficking, cell proliferation, signaling, immortalization and tumorigenesis.
Thus, inhibition of mortalin is a promising avenue for cancer remedy. Previous research in our lab have recommended that mortalin contributes to breast cancer improvement and development.
We confirmed that tumor furthermobile vesicle secretion was decreased by knockdown of mortalin expression utilizing HIV-1 Nef SMR peptides. Specifically, these peptides can block furthermobile vesicle secretion and mediate cell cycle arrest in MDA-MB-231 and MCF-7 breast cancer cells.
Aims: This research goals to research additional the operate and mechanism of interplay of PEG-SMR-CLU and SMR-CPP peptides with the chaperone protein mortalin and to discover the impact of SMR-derived peptides and mortalin expression on furthermobile vesicle release and complement dependent cell toxicity in human breast cancer and leukemia cell lines.
Results: Our outcomes demonstrated further results reversing the tumorigenicity of these cells. First, the modified SMRwt peptides diminished the expression of the mesenchymal marker vimentin (VIM).
Second, publicity to the SMRwt peptide inhibited mortalin and complement C9 expression in MDA-MB-231, MCF-7 breast cancer cells and Okay562 leukemia cells as measured by the Western blot evaluation.
Third, the SMRwt peptides blocked the cancer cells’ capability to release furthermobile vesicles, which we noticed blocked furthermobile vesicle-mediated release of complement, re-establishing enhances mediated cell loss of life in these peptide-treated cells.
Methods: We developed a collection of peptides derived from the Secretion Modification Region (SMR) of HIV-1 Nef protein, modified by the addition of both a cell-penetrating peptide (CPP), a positively charged arginine-rich peptide derived from HIV-1 regulatory protein Tat, or a Clusterin-binding peptide (CLU), a molecular chaperone concerned in protein secretion.
Both CPP and CLU peptide sequences had been added on the C-terminus of the Nef SMR peptide. The CLU-containing peptides had been additionally modified with polyethylene glycol (PEG) to reinforce solubility.
After therapy of cells with the peptides, we used the MTT cell viability and complement-mediated cytotoxicity assays to substantiate the inhibitory function of modified SMRwt peptides on the proliferation of MDA-MB-231 and MCF-7 breast cancer cells and Okay562 leukemia cells.
Flow cytometry was used to find out complement mediated cell apoptosis and loss of life. Western blot evaluation was used to trace SMR peptides impression on expression of mortalin, vimentin and complement C9 and to measure the expression of furthermobile vesicle proteins.
NanoSight evaluation and acetylcholinesterase (AChE) assay had been used for measuring furthermobile vesicles particle measurement and focus and acetylcholinesterase.
Conclusions: Mortalin promotes cell proliferation, metastasis, angiogenesis, downregulate apoptotic signaling. Thus, mortalin is a possible therapeutic goal for cancer immunotherapy. The novel SMRwt peptides antagonize the features of mortalin, blocking tumor furthermobile vesicle release and furthermobile vesicle-mediated release of complement.
This results in decreases in breast cancer cell metastasis and permits normal therapy of these late stage tumor cells, thus having necessary scientific implications for late stage breast cancer chemotherapy. These findings help additional investigation into the therapeutic worth of the SMR peptide in cancer metastasis.
- Written by: Frank
- Category: Malignant transformation in a Breast Adenomyoepithelioma Caused by Amplification of c-MYC: A Common pathway to Cancer in a Rare Entity.
- Published: May 10, 2020
Breast adenomyoepitheliomas are composed of a biphasic proliferation of myoepithelial cells round small epithelial-lined areas. Due to the rarity of adenomyoepitheliomas, the molecular knowledge describing them are restricted. Adenomyoepitheliomas are thought-about to be benign or have low malignant potential, and be susceptible to native recurrence.
Malignant transformation has been related to homozygous deletion of CDKN2A or somatic mutations in TERT, however stays unexplained in many circumstances.
Here, we describe a case of carcinomatous transformation of each epithelial and myoepithelial cells in an estrogen receptor-negative adenomyoepithelioma triggered by amplification of MYC.
Break-apart fluorescence in situ hybridization revealed a rise in the MYC gene copy quantity (3-Four copies/cell in 37%, > Four copies/cell in 40%). Deregulation of MYC is accountable for uncontrolled proliferation and cellularimmortalization in basal-like breast cancers.
Our case demonstrates that genomic instability occasions related to gene amplification could also be concerned in the carcinogenesis of malignant adenomyoepitheliomas.
Mitochondrial dynamics and metabolism in induced pluripotency.
Somatic cells will be reprogrammed to pluripotency by both ectopic expression of outlined components or publicity to chemical cocktails.
During reprogramming, somatic cells endure dramatic modifications in a wide selection of mobile processes, equivalent to metabolism, mitochondrial morphology and performance, cell signaling pathways or immortalization. Regulation of these processes throughout cell reprograming lead to the acquisition of a pluripotent state, which permits indefinite propagation by symmetrical self-renewal with out dropping the power of reprogrammed cells to differentiate into all cell varieties of the grownup.
In this evaluation, latest knowledge from totally different laboratories displaying how these processes are managed throughout the phenotypic transformation of a somatic cell into a pluripotent stem cell will likely be mentioned.
This week we will talk about the transformation of human fibroblasts into hepatocytes using the biotechnological techniques: infection with lentiviral vectors and cellular immortalization. The purpose? Study a situation with a high idiosyncratic component: the damage that causes the liver of each person and the consumption of medicines. The authors? The Experimental Hepatología Unit of the Instituto de Investigación Sanitaria La Fe de Valencia… FOLLOW LEYENDO!
What does this strategy consist of?
From somatic cells (any cell in our body except sexual cells) of the individual in the studio, and transform them into cells with a hepatocyte-like phenotype (which in English is called hepatocyte-like cells) to be able to work with them in vitro form.
For him, we have to speak of the strategies: cellular immortalization and lentiviral infection; and some concept like: cell line or primary cultivation.
If we put ourselves in context, to study the liver damage of a patient the most obvious would be to show hepatocytes of the patient and cultivate them. Using cells obtained directly from an organ, the fabric is called primary culture. What is your main disadvantage? That in vitro growth is very limited. This is how it is difficult to extract hepatocytes from a patient.
Not only will you finish imagining it, the habitants will sometimes work with cell cultures. When we were able to grow cells, we were able to extend them on different “platitos” and wait for them to grow to try them out and keep them in cultivation, turning them on another plate or plate. In vitro, it is called in vitro by the original material of these plates, the glass.
How can it be an alternative to these primary crops?
Realize a transformation or cellular immortalization. To decide, to co-operate this primary culture and to induce some change so that these cells can multiply indefinitely, let us turn them to death. In this case, we would be talking about a cell line. A set of cells that you can maintain indefinitely in cultivation to work with them comfortably.
Do you disadvantages? The immortalization process could change its phenotype (the observable characteristics derived from combining genes and the environment), and they are not identical to the original cells.
How can a cell be immortalized? It may seem like a twist, but there are only so many strategies. In this case we will focus on the method followed by these researchers: using the SV40 T large antigen.
SV40 is a virus capable of infecting both humans and humans. What is interesting? A gen that houses its genome. This gene produces the protein known as the large SV40 antigen. This protein is able to block the p53 action.
We have also spoken on other occasions of this tumor suppressor, we have a small reminder. p53, known as the guardian of the genome, is the protein responsible for detecting irreparable damage in the genome of other cells and activating its mutation.
In this way, it avoids that damage in the DNA (which could end up leading to mutations and tumors, simply due to the aging of the cell) is not transmitted to new cells.
Who can get the large antigen from the SV40? One joins an essential region for the function of p53, completely blocking its action. So, this cell will be unable to detect the changes in the genome and it will never die, becoming literally and immortal.
Of course, p53 is known as a tumor suppressor because it stops the accumulation of mutations that could lead to cancer. Unfortunately, there are only one of the main genes that appear to be altered in tumor cells, which we think are also deadly.
We will now go to lentiviral infection. This concept is easily understandable if we understand how a virus works. A virus comes into contact with a cell and inserts its genetic material.
In this way, the DNA (the RNA) of the virus multiplies using our own cells, so that it can continue to infect. Well, when we refer to lentiviral infection, we are talking about cogerating these viruses, making changes in their genome so that in the future this ability to jump from cell to cell, and to change our genes or genes of interest.
How did we get there? That using a virus-friendly mechanism, we introduce into the genome of cells the genes that interest us.
And the concepts are cleared, now we can understand the work of this group of researchers: Once the patients’ fibroblasts were isolated, these cells were subjected to lentiviral infections.
Firstly, to introduce the SV40 large T antigen into its genome and immortal cells to easily work in vitro. And secondly, with a cocktail of genes needed to express a hepatocyte phenotype.
What gene cocktail? Genes for three transcription factors: HNF4A, HNF1A and FOXA3. The factors of transcription in proteins are charges to induce the expression (transformation into protein) of other genes.
These 3 transcription factors are key to expressing essential genes for a liver phenotype. In short, these transcription factors induce the expression of genes that provide a cell with the proper characteristics of a liver cell.
More details? These researchers used an inducible transcription factor expression system. Decide, these factors will only be expressed, and will transform the cell into hepatocyte, when we want it. As? Using a doxycycline-activated promoter.
Very straightforward: the sequence of any genre preceded by another sequence, the promoter. This promoter is responsible for allowing, however, the expression of the genes that they have by default. It is precisely in this region from which the transcriptional factors are united to activate the expression of the genes they control.
In this specific system, the 3 transcription factors have been inserted into the fibroblast genome with a forward promoter. Promoter that only activates and induces the expression of two factors when researchers add to the doxycycline cultivation.
If this antibiotic is not present, the cells follow the fibroblast and can be maintained indefinitely in culture. If doxycycline is used, the transcription factors are expressed and can, in turn, induce the expression of the genes that “transform” the fibroblast into hepatocyte.
The result? Cells owned by a patient (with their genome), easily isolated (from the skin), immortalized (never dying) and with characteristics of the same patient’s hepatocytes (as a result of these three genes).
Thanks to this strategy, it is possible to work in vitro with the individual cells of each patient, avoiding the use of primary cultures and their disadvantages, and I could study the characteristic changes of each patient in response to the liver by drugs.
With the arrival of winter, concerns about the transmission of several viruses, especially the flu, increase. When people think of viruses, they quickly associate them with diseases or chemical weapons. However, for us, biotechnologists, they can also be important tools, as we can use their ability to infiltrate and exploit living systems in favor of society. Calm down, I’ll explain to you how this is possible!
Well, initially it is necessary for you to understand that viruses are basically composed of a genetic material inside a protein capsule, thus, they are not considered living beings, as they cannot replicate by themselves. Once they infect cells that allow them to replicate, they lose their identity of origin and act under viral command.
Now that you know how viruses replicate, it’s important to know that even bacteria are targets for these smarties: phages (or bacteriophages) are viruses that only infect bacteria. This is exactly where biotechnology comes in, and we think: Now, if phages are capable of killing bacteria, it can become an advantage for humans, who can use them to kill unwanted bacteria.
Since then, they have been extensively researched for complementary use in antibiotic therapy, since they are immune to the resistance mechanism and specific to their host (each phage only infects one strain of bacteria). This feature prevents the “beneficial” bacteria from being destroyed. However, in order to use this treatment it is necessary to carry out laboratory tests to identify precisely which species of bacteria caused the infection. Studies are also needed to monitor, in the long run, whether bacteria can evolve into phage resistance. However, when bacteria become resistant to one phage, they become susceptible to another. In this way there is almost an endless supply of possible new treatments.
Until recently, there was no way to kill cancer cells without harming healthy cells in the rest of the body, due to the difficulty of targeting a treatment that affected only those affected. However, biotechnology has revolutionized this scenario by developing viruses that selectively destroy tumors. Amgen’s T-VEC is a herpes oncolytic virus, genetically modified to treat melanoma, killing cancer cells in the skin without affecting healthy cells. This is possible because the modified herpes virus can only replicate within cancer cells. They are injected directly into the tumor until the cancer subsides, for approximately four months.
In Germany, ParvOryxo was developed, which selectively kills tumor cells from a wide variety of tumors including glioblastoma and pancreatic cancer. It is able to pass the blood-brain barrier, which protects the brain, directly killing tumor cells, in addition to altering the tumor’s microenvironment, making it more visible to the immune system and increasing its vulnerability to immuno-oncology approaches.
“Pigeons carrier” of genetic material (viral vectors)
When removing the pathogenic components of the virus genome, they can be used as true “pigeons”, delivering genes of interest in genetic therapies. Luxturna, for example, is a viral vector that carries a functional copy of the RPE65 gene in retinal cells, restoring the vision of patients with progressive vision loss due to a mutation.
Although its sinister reputation can never be completely erased, there is no denying that viruses are far from just carrying disease and death. They can act as fantastic biotechnological tools, capable of providing powerful treatments that would be impossible without your help.
There are many methods consist on the identifcation of the repiratory virus.
Viral respiratory infection can be caused by nemerous viruses:
- RSV A and RSV B (Respiratory Syncytial Virus).
- Parainfluenza Virus (types 1–4).
- Numerous Adenoviruses.
- Avian Influenza Virus (H5N1 and H7N9).
- Coronaviruses; including SARS (Severe Acute Respiratory Virus) and SARS-COV2 (The novel coronavirus which is responsible for COVID-19.
The above listed viruses causes different respiratory infection with symptoms from mild to severe, and thus form runny nose and sneezing to pharyngitis, laryngitis, bronchitis, or pneumonia.
The severity of disease varies depending on the level of immunity of the individual.
There are many methods for the diagnosis of the respiratory viruses; we can say that there is traditional methods and molecular methods.
The traditional methods are:
This method consist on:
- Isolation of the virus in cell cultures
- Incubation of specimen with these cell cultures in tubes.
- Placing the tubes in roller drum (Rotate for almost 10 days).
- Observing daily the cells under the microscopes, the damaged cells indicate the presence of the virus.
The inconvenient of this method is that not all viruses are culturable, and this method is not sensitive enough when antibodies in the specimen neutralize the virus.
Direct Fluorescent Antibody (FDA)
This methode consit on staining or the presence of virus-infected cells.
- collection of epithelial cells from a nasopharyngeal swab.
- fixing the epithelial cells to a glass microscope slide.
- Staining with individual antibodies labeled with a fluorescent tag.
- Viewing the slide with a fluorescent microscope.
Shell Vial Culture
This method consist on:
- Inoculation of an aliquot of the specimen onto a preformed cell monolayer in a small vial containing a mixture of two susceptible cells.
- Centrifugation to enhance virus attachment and entry.
- The centrifugation-assisted inoculation of the cells increases the amount of viral proteins produced.
- This allows staining to be performed at 24–48 h and thus providing a test result to be obtained significantly earlier than the 7–10 days necessary for traditional cell culture.
Enzyme-linked immunosorbent assays (ELISA)
The rapid enzyme-linked immunosorbent assays (ELISAs) consist on using a monoclonal conjugated antibody to an enzyme to quantify and detect the presence of a specific antigen in a sample.
The molecular methods are:
Nucleic Acid Amplification Tests (NAAT)
This technique started in the late 1980s, developped for the the first time for the influenza, In 1983; 1983 by Kary B. Mullis ( used a nucleic acid amplification method called Polymerase Chain Reaction (PCR).
Within a decade, NAATs were developed for all of the respiratory viruses.
The most used technique is PCR, but there are other techniques:
- Strand Displacement Amplification (SDA).
- Nucleic Acid–Sequence-Based Amplification (NASBA).
- Transcription-Mediated Amplification (TMA).
- Loop-Mediated Isothermal Amplification (LAMP).
These all NAATs techniques consist on:
- Extraction of the nucleic acid from the respiratory tract specimen.
- Copying the viral ribobucleic acid (RNA) into a complementary deoxyribonucleic acid (cDNA) by the enzyme Reverse transcriptase.
- Amplifying the cDNA by PCR using a virus-specific oligonucleotide primers.
- The result is a billion copies of DNA.
- These DNAs can then easily detected by different laboratory methods.
Molecular methods are more sensitive than traditional methods, they are also efficient and give results in a very short time.