Cisplatin is an effective chemotherapeutic agent, but its use is limited by nephrotoxicity. Cisplatin accumulates in kidney cells via transporters OCT2 and Ctr1. In kidney cells, cisplatin undergoes biotransformation to a more toxic form. Cisplatin causes DNA and protein damage, inducing both necrosis and apoptosis in proximal and distal tubule cells. Apoptosis occurs via the extrinsic pathway through TNF-α activation and the intrinsic mitochondrial pathway. Preventing cisplatin accumulation and activation, as well as inhibiting apoptosis and inflammation, may reduce nephrotoxicity. Volume expansion remains the primary clinical prevention strategy.

1. Molecular mechanism involved in
cisplatin induced nephrotoxicity
By:
Saloni Verma
M. pharm pharmacology
Central university of Punjab, bathinda

2. contents
• Introduction
• History
• Mechanism
• Cell death
• Apoptotic pathways

3. Introduction
• Cisplatin (cis-diamminedichloroplatinum II, CDDP) is one of the most
effective chemotherapeutic agents.
• its clinical use is limited due to the severe side effects, including
nephrotoxicity and acute kidney injury (AKI) which develop due to
renal accumulation and biotransformation of CDDP.
• Most drug found to cause nephrotoxicity exert toxic effects
by more than one pathogenic pathways.
• These include altered intraglomerular, hemodynamics, tubular cell
toxicity, inflammation, crystal, nephropathy etc.,
• Pathophysiological mechanism of cisplatin induced nephrotoxicity
is chronic interstitial nephritis, tubular cell toxicity.

4. Renal manifestations of cisplatin treatment
• Acute kidney injury
• Hypomagnesemia
• Fanconi like syndrome
• Distal renal tubule acidosis
• Hypocalcaemia
• Renal salt wasting
• Renal concentrating defect
• Hyperuricemia
• Transient proteinuria

5. history
• This chemical had first been synthesized in 1845 and was known as
peyrone’s chloride
• Cisplatin is platinum containing drug first approved as an
antineoplastic agent in 1978.
• Cisplatin was first shown to inhibit cell division in 1965.
• By 1969, cisplatin was found to have anti-tumor effects in animal
models.
• The first report of nephrotoxicity in animal studies was in 1971,which
demonstrated histopathologic changes of acute tubular necrosis along
with azotemia

6. MECHANISMS OF CISPLATIN NEPHROTOXICITY
1. Accumulation of cisplatin in kidney cells
• Cisplatin is cleared by the kidney by both glomerular filtration and tubular secretion.
• Studies using kidney slices, cultured renal epithelial cells and isolated perfused proximal tubule
segments have provided evidence for basolateral-to-apical transport of cisplatin.
• Two different membrane transporters capable of transporting cisplatin into cells:
I. Ctr1 and OCT2. Ctr1 is a copper transporter which was also shown to mediate cisplatin uptake
into mammalian cells, including ovarian cancer cells. Ctr1 is highly expressed in adult kidney
and the protein localizes to the basolateral membrane of the proximal tubule,
II. the organic cation transporter OCT2 (SLC22A2) transports cisplatin. Cisplatin was shown to
inhibit the uptake of other OCT2 substrates, consistent with the view that these substrates
share a common transport pathway. Two recent observations point to an important role for
OCT2 in mediating renal cisplatin uptake and toxicity. First, knockout of the OCT2 gene
significantly reduced urinary cisplatin excretion and nephrotoxicity. Second, a nonsynonymous
single-nucleotide polymorphism (SNP) in the OCT2 gene (rs316019) was associated with
reduced cisplatin-induced nephrotoxicity in patients.

7. BIOTRANSFORMATION OF CISPLATIN IN THE KIDNEY
• Studies in rats and mice indicate that cisplatin undergoes metabolic activation in
the kidney to a more potent toxin.
• This process begins with the formation of glutathione conjugates in the
circulation, perhaps mediated by glutathione-S-transferase. As the glutathione-
conjugates pass through the kidney, they are cleaved to cysteinyl-glycine-
conjugates by gamma glutamyl transpeptidase (GGT) expressed on the surface of
the proximal tubule cells.
• The cysteinyl-glycine-conjugates are further metabolized to cysteine-conjugates
by amino dipeptidases, also expressed on the surface of the proximal tubule cells.
The cysteine-conjugates are transported into the proximal tubule cells, where
they are further metabolized by cysteine-S-conjugate beta-lyase to highly reactive
thiols.

8. CELLULAR TARGET OF CISPLATIN
• Platinum compounds are believed to mediate their cytotoxic effects through their
interaction with DNA.
• In an aqueous environment, the chloride ligands of cisplatin are replaced by
water molecules generating a positively charged electrophile.
• This electrophile reacts with nucleophilic sites on intracellular macromolecules to
form DNA, RNA, and protein adducts. Cisplatin binds to DNA leading to the
formation of inter- and intra strand cross-links, thereby arresting DNA synthesis
and replication in rapidly proliferating cells.

9. CELL DEATH IN CISPLATIN NEPHROTOXICITY(TYPES &
LOCATION)
• Renal tissue damage, which is tubular cell death, is a common histopathological feature of
cisplatin nephrotoxicity. In this condition, cell death in the form of both necrosis and apoptosis is
identified.
• Using cultured renal tubular cells, earlier observations by suggested ,dosage of cisplatin might
determine whether the cells die by necrosis or apoptosis.
• Necrotic cell death was observed when a high concentration of cisplatin (in millimolar) was used,
while lower concentrations of cisplatin (in micromolar) led to apoptosis. It is recognized that
renal tubules are the major sites of cell injury & death during cisplatin nephrotoxicity. Earlier
study suggested that the distal tubules were the primary site of apoptosis and recent studies
indicated that proximal tubular cells also undergo apoptosis during cisplatin nephrotoxicity.
• It was shown that many apoptotic cells were stained by phytohemagglutinin, a proximal tubule-
binding lectin, whereas significantly fewer apoptotic cells were stained by peanut lectin
agglutinin, a distal tubule-binding lectin. Thus, apoptosis occurs in both tubular segments, but the
majority is in proximal tubules.

10. APOPTOTIC PATHWAY OF CISPLATIN NEPHROTOXICITY
• The mechanisms of cisplatin-induced nephrotoxicity are complex and
involve multiple pathways and molecules.
• Several pathways of apoptosis have been implicated, including :
1. The extrinsic pathway mediated by death receptors(TNF-a)
2. The intrinsic pathway centered on mitochondria
3. The endoplasmic reticulum (ER)-stress pathway

11. Oct2/ctr1
Apoptosis
AIF
Caspase
independent
Caspase 12
activation
Cytochrome c
Caspase 9 activation
Caspase 8 activation
ER stress Death receptor pathway
Mitochondrial pathway

12. Extrinsic pathway
• The cisplatin activates the p38 kinases ( MAPK) , which
increases the production of tumor necrosis factor-a (TNF-a).
• TNF-α stimulates an inflammatory response in vivo which
exacerbates cisplatin nephrotoxicity
• The biological activities of TNF-a are mediated by two
functionally distinct receptors, TNFR1 (p55) and TNFR2 (p75).
• TNFR1 contains a conserved ‘death domain,’ which, upon
TNF-α ligation, can trigger the formation of a caspase-
activation complex, leading to apoptosis.
• TNFR2 plays a pathogenic role in stimulating cytokine and
chemokine expression and producing acute renal failure.
• In the extrinsic pathway, TNF-α activate caspase-8, which
further activate downstream caspases (caspase3/6/7) to
induce apoptosis.

13. Intrinsic or mitochondrial pathway
• The mitochondrial or intrinsic pathway is a key factor for renal tubular cell death in cisplatin-induced
nephrotoxicity.
• The p53 tumor suppressor induces apoptosis in response to DNA damage by cisplatin.
• Two targets of p53 transcriptional regulation, p53 up-regulated modulator of apoptosis-alpha (PUMA-α) and
p53-induced protein with a death domain (PIDD), may mediate p53 actions in cisplatin cell death.
• PUMA-α and PIDD are proapoptotic Bcl-2 family protein which are induced by cisplatin in a p53-dependent
manner
• BCL-2 family pro-apoptotic proteins (BAX and BAK) function as 'molecular integrators' to the mitochondrial
pathway.
• After exposure to cisplatin, pro-apoptotic proteins BAX and BAK undergo structural modifications and alter
the integrity of the mitochondrial membrane to cause the release of apoptogenic factors such as
• cytochrome C (caspases activator) and
• apoptosis-inducing factor (AIF), a caspase-independent cell death promoter.
• Cytochrome c activate caspase 9 which lead to apoptosis.
• In contrast, AIF, after being released from mitochondria, accumulates in the nucleus to induce apoptosis in a
caspase-independent manner.

14. Flow chart cisplatin
DNA damage
PIDD/PUMA-α
BAX/BAK
Mitochondria
AIF Cytochrome C
Caspase 9
Apoptosis
p53
Caspase independent

15. Prevention of cisplatin nephrotoxicity
• Volume expansion with sodium chloride has been the primary means
to reduce cisplatin nephrotoxicity.
• Though many hydration regimens include the use of mannitol or
furosemide, there is no proper evidence that diuretics provide any
added benefit. In fact, one comparative trial found greater
nephrotoxicity in patients who received saline plus mannitol
compared with saline alone.
• Hypertonic (3%) saline has also been advocated. some studies
showed decreases in GFR despite the use of 3% saline. Recently
published clinical guidelines recommend prehydration with 0.9%
saline and avoidance of diuretics.

16. EXPERIMENTAL STRATGIES TO PREVENT CISPLATIN
NEPHROTOXICITY.
Reduced renal cisplatin
accumulation or activation
Anti-oxidants Anti-apoptosis Anti-inflammation
OCT2 inhibitors, e.g., Cimetidine Amifostine P53 inhibitors TLR4 antagonists
Ctr1 inhibitors, e.g., copper BNP7787 HDAC inhibitors P38 inhibitors
Micellar cisplatin N-acetyl cysteine Caspase inhibitors JNK inhibitors
Gamma-glutamyl transpeptidase
inhibitors
Catalase CDK2 inhibitors Salicylates
Glutathione transferase
inhibitors
Superoxide dismutase